MAX6383XR23D7+T中文资料

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MAX832中文资料

NUAL KIT MA ATION U EET L H A S V A E T WS DA FOLLO
___________________________Features
o Input Range: Up to 30V o 1A On-Chip Power Switch o Adjustable Output (MAX830) Fixed Outputs: 5V (MAX831) 3.3V (MAX832) 3V (MAX833) o 100kHz Switching Frequency o Excellent Dynamic Characteristics o Few External Components o 8mA Quiescent Current o 16-Pin SO Package o Evaluation Kit Available
__________Typical Operating Circuit
__________________Pin Configuration
TOP VIEW
INPUT 8V TO 30V 100µF VIN VSW
100µH*
OUTPUT 5V AT 1A
V IN 1 V IN 2 V IN 3
16 V SW 15 V SW 14 V SW
_______________________Applications
Distributed Power from High-Voltage Buses High-Current, High-Voltage Step-Down Applications Multiple-Output Buck Converter
MAX831
VC 10k 0.047µF SENSE

MAX6303中文资料

( ) ARE FOR MAX6302/MAX6304.
* Patents pending
________________________________________________________________ Maxim Integrated Products 1
For free samples & the latest literature: , or phone 1-800-998-8800
MAX6301–MAX6304
________________________Applications
Medical Equipment Intelligent Instruments Portable Equipment Battery-Powered Computers/Controllers Embedded Controllers Critical µP Monitoring Set-Top Boxes Computers
ELECTRICAL CHARACTERISTICS
(VCC = +2V to +5.5V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) PARAMETER Operating Voltage Range (Note 1) Supply Current (Note 2) RESET TIMER Reset Input Threshold Voltage Reset Input Hysteresis Reset Input Leakage Current Reset Output Voltage High (MAX6302/MAX6303/MAX6304) VTH VHYST IRESET IN VCC ≥ 4.5V, ISOURCE = 0.8mA VOH VCC = 2V, ISOURCE = 0.4mA MAX6302/MAX6304, VCC = 1.31V, RL = 10kΩ VCC ≥ 4.5V, ISINK = 3.2mA VCC = 2V, ISINK = 1.6mA Reset Output Voltage Low (MAX6301/MAX6303/MAX6304) VOL MAX6301/ MAX6303 VCC = 1V, ISINK = 50µA, TA = 0°C to +70°C VCC = 1.2V, ISINK = 100µA, TA = -40°C to +85°C 63 26 2.8 4.0 5.2 ±1 ±1 VCC - 0.3 0.4 0.4 0.3 0.3 µs µs ms µA V VCC - 0.4 VCC - 0.4 V VRESET IN falling, VCC = 5.0V VRESET IN rising, VCC = 5.0V 1.195 1.220 1.240 20 ±0.01 ±1 1.245 1.265 V mV nA SYMBOL VCC ICC CONDITIONS MAX6301C/MAX6303C MAX6301E/MAX6303E MAX6302/MAX6304 No load MIN 1.00 1.20 1.31 4.0 TYP MAX 5.50 5.50 5.50 7.0 µA V UNITS

MAX6387XS33D7-T中文资料

General DescriptionThe MAX6381–MAX6390 microprocessor (µP) supervisory circuits monitor power supply voltages from +1.8V to +5.0V while consuming only 3µA of supply current at +1.8V. Whenever V CC falls below the factory-set reset thresholds, the reset output asserts and remains assert-ed for a minimum reset timeout period after V CC rises above the reset threshold. Reset thresholds are available from +1.58V to +4.63V, in approximately 100mV incre-ments. Seven minimum reset timeout delays ranging from 1ms to 1200ms are available.The MAX6381/MAX6384/MAX6387 have a push-pull active-low reset output. The MAX6382/MAX6385/MAX6388 have a push-pull active-high reset output,and the MAX6383/MAX6386/MAX6389/MAX6390 have an open-drain active-low reset output. The MAX6384/MAX6385/MAX6386 also feature a debounced manual reset input (with internal pullup resistor). The MAX6387/MAX6388/MAX6389 have an auxiliary input for monitoring a second voltage. The MAX6390 offers a manual reset input with a longer V CC reset timeout period (1120ms or 1200ms) and a shorter manual reset timeout (140ms or 150ms).The MAX6381/MAX6382/MAX6383 are available in 3-pin SC70 packages and the MAX6384–MAX6390 are avail-able in 4-pin SC70 packages.________________________ApplicationsComputers ControllersIntelligent InstrumentsCritical µP and µC Power Monitoring Portable/Battery-Powered Equipment Dual Voltage SystemsFeatureso Factory-Set Reset Threshold Voltages Ranging from +1.58V to +4.63V in Approximately 100mV Increments o ±2.5% Reset Threshold Accuracy Over Temperature (-40°C to +125°C)o Seven Reset Timeout Periods Available: 1ms,20ms, 140ms, 280ms, 560ms, 1120ms, 1200ms (min)o 3 Reset Output OptionsActive-Low Push-Pull Active-High Push-Pull Active-Low Open-Draino Reset Output State Guaranteed Valid Down to V CC = 1Vo Manual Reset Input (MAX6384/MAX6385/MAX6386)o Auxiliary RESET IN(MAX6387/MAX6388/MAX6389)o V CC Reset Timeout (1120ms or 1200ms)/Manual Reset Timeout (140ms or 150ms) (MAX6390)o Negative-Going V CC Transient Immunity o Low Power Consumption of 6µA at +3.6V and 3µA at +1.8V o Pin Compatible withMAX809/MAX810/MAX803/MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX6348, and MAX6711/MAX6712/MAX6713o Tiny 3-Pin SC70 and 4-Pin SC70 PackagesMAX6381–MAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits________________________________________________________________Maxim Integrated Products1Pin Configurations19-1839; Rev 1; 04/01Ordering InformationOrdering Information continued at end of data sheet.Typical Operating Circuit appears at end of data sheet.Selector Guide appears at end of data sheet.Note:Insert reset threshold suffix (see Reset Threshold table)after "XR" or "XS". Insert reset timeout delay (see Reset Timeout Delay table) after "D" to complete the part number. Sample stock is generally held on standard versions only (seeStandard Versions table). Standard versions have an order increment requirement of 2500 pieces. Nonstandard versions have an order increment requirement of 10,000 pieces.Contact factory for availability of nonstandard versions.*MAX6390 is available with D4 or D7 timing only.For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .M A X 6381–M A X 6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICSStresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.V CC to GND..........................................................-0.3V to +6.0V RESET Open-Drain Output....................................-0.3V to +6.0V RESET , RESET (Push-Pull Output).............-0.3V to (V CC + 0.3V)MR , RESET IN.............................................-0.3V to (V CC + 0.3V)Input Current (V CC ).............................................................20mA Output Current (All Pins).....................................................20mAContinuous Power Dissipation (T A = +70°C)3-Pin SC70 (derate 2.9mW/°C above +70°C)........235mW 4-Pin SC70 (derate 3.1mW/°C above +70°C)........245mW Operating Temperature Range .........................-40°C to +125°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°CMAX6381–MAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits_______________________________________________________________________________________3M A X 6381–M A X 6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 4______________________________________________________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)215436789-40-105-25203550658095110125SUPPLY CURRENT vs. TEMPERATURE(NO LOAD)TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )25292735333137394143-40-105-25203550658095110125POWER-DOWN RESET DELAYvs. TEMPERATURETEMPERATURE (°C)P O W E R -D O W N R E S E T D E L A Y (µs )0.940.980.961.021.001.061.041.08-40-10520-253550658095110125NORMALIZED POWER-UP RESET TIMEOUTvs. TEMPERATUREM A X 6381/90 t o c 03TEMPERATURE (°C)N O R M A L I Z E D R E S E T T I M E O U T P E R I O D0.9900.9851.0150.9950.9901.0001.0051.0101.020-40-10520-253550958011065125M A X 6381/90 t o c 04TEMPERATURE (°C)N O R M A L I Z E D R E S E TT H R E S H O L D NORMALIZED RESET THRESHOLDvs. TEMPERATURE00.40.20.80.61.01.2063912OUTPUT VOLTAGE LOW vs. SINK CURRENTI SINK (mA)V O L (V )01.00.52.01.52.53.00500750250100012501500OUTPUT VOLTAGE HIGH vs. SOURCE CURRENTI SOURCE (µA)V O H (V )45001100010010MAXIMUM TRANSIENT DURATION vs. RESET COMPARATOR OVERDRIVE15050350250500200100400300RESET COMPARATOR OVERDRIVE, V TH - V CC (mV)M A X I M U M T R A N S I E N T D U R A T I O N (µs )3.53.93.74.54.34.14.74.95.35.15.5-40-105-25203550658095110125RESET IN TO RESET DELAYvs. TEMPERATUREM A X 6381/90 t o c 08TEMPERATURE (°C)R E S E T I N D E L A Y (µs )MAX6381–MAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits_______________________________________________________________________________________5M A X 6381–M A X 6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 6_______________________________________________________________________________________Detailed DescriptionRESET OutputA µP reset input starts the µP in a known state. These µP supervisory circuits assert reset to prevent code execution errors during power-up, power-down, or brownout conditions.Reset asserts when V CC is below the reset threshold;once V CC exceeds the reset threshold, an internal timer keeps the reset output asserted for the reset timeout period. After this interval, reset output deasserts. Reset output is guaranteed to be in the correct logic state for V CC ≥1V.Manual Reset Input (MAX6384/MAX6385/MAX6386/MAX6390)Many µP-based products require manual reset capabil-ity, allowing the operator, a test technician, or external logic circuitry to initiate a reset. A logic low on MR asserts reset. Reset remains asserted while MR is low,and for the reset active timeout period (t RP ) after MR returns high. This input has an internal 63k Ωpullup resistor (1.35k Ωfor MAX6390), so it can be left uncon-nected if it is not used. MR can be driven with TTL or CMOS logic levels, or with open-drain/collector outputs.Connect a normally open momentary switch from MR to G ND to create a manual-reset function; external debounce circuitry is not required. If MR is driven from long cables or if the device is used in a noisy environ-ment, connecting a 0.1µF capacitor from MR to G ND provides additional noise immunity.RESET IN Comparator(MAX6387/MAX6388/MAX6389)RESET IN is compared to an internal +1.27V reference.If the voltage at RESET IN is less than 1.27V, reset asserts. Use the RESET IN comparator as a user-adjustable reset detector or as a secondary power-sup-ply monitor by implementing a resistor-divider at RESET IN (shown in Figure 1). Reset asserts when either V CC or RESET IN falls below its respective threshold volt-age. Use the following equation to set the threshold:V INTH = V THRST (R1/R2 + 1)where V THRST = +1.27V. To simplify the resistor selec-tion, choose a value of R2 and calculate R1:R1 = R2 [(V INTH /V THRST ) - 1]Since the input current at RESET IN is 50nA (max),large values can be used for R2 with no significant loss in accuracy.___________Applications InformationNegative-Going V CC TransientsIn addition to issuing a reset to the µP during power-up,power-down, and brownout conditions, the MAX6381–MAX6390 are relatively immune to short dura-tion negative-going V CC transients (glitches).The Typical Operating Characteristics section shows the Maximum Transient Durations vs. Reset Comparator Overdrive, for which the MAX6381–MAX6390 do not generate a reset pulse. This graph was generated usinga negative-going pulse applied to V CC , starting above the actual reset threshold and ending below it by the magni-tude indicated (reset comparator overdrive). The graph indicates the typical maximum pulse width a negative-going V CC transient may have without causing a reset pulse to be issued. As the magnitude of the transient increases (goes farther below the reset threshold), the maximum allowable pulse width decreases. A 0.1µF capacitor mounted as close as possible to V CC provides additional transient immunity.Ensuring a Valid RESET Output Down to V CC = 0The MAX6381–MAX6390 are guaranteed to operate properly down to V CC = 1V. In applications that require valid reset levels down to V CC = 0, a pulldown resistor to active-low outputs (push/pull only, Figure 2) and a pullup resistor to active-high outputs (push/pull only) will ensure that the reset line is valid while the reset output can no longer sink or source current. This scheme doesnot work with the open-drain outputs of the MAX6383/MAX6386/MAX6389/MAX6390. The resistor value used is not critical, but it must be small enough not to load the reset output when V CC is above the reset threshold. For most applications, 100k Ωis adequate.MAX6381–MAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits_______________________________________________________________________________________7M A X 6381–M A X 6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 8Selector GuideChip InformationTRANSISTOR COUNT: 647PROCESS: BiCMOS*MR is for MAX6384/MAX6385/MAX6386/MAX6390**RESET IN is for MAX6387/MAX6388/MAX6389( ) are for MAX6382/MAX6385/MAX6388Pin Configurations (continued)MAX6381–MAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits_______________________________________________________________________________________9Ordering Information(continued)Note:Insert reset threshold suffix (see Reset Threshold table)after "XR" or "XS". Insert reset timeout delay (see Reset Timeout Delay table) after "D" to complete the part number. Sample stock is generally held on standard versions only (seeStandard Versions table). Standard versions have an order increment requirement of 2500 pieces. Nonstandard versions have an order increment requirement of 10,000 pieces.Contact factory for availability of nonstandard versions.*MAX6390 is available with D4 or D7 timing only.M A X 6381–M A X 6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 10______________________________________________________________________________________Package InformationSC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsMaxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600____________________11©2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.MAX6381–MAX6390Package Information (continued)元器件交易网。

MAX6372KA-T中文资料

General DescriptionThe MAX6369–MAX6374 are pin-selectable watchdog timers that supervise microprocessor (µP) activity and signal when a system is operating improperly. During normal operation, the microprocessor should repeated-ly toggle the watchdog input (WDI) before the selected watchdog timeout period elapses to demonstrate that the system is processing code properly. If the µP does not provide a valid watchdog input transition before the timeout period expires, the supervisor asserts a watch-dog (WDO ) output to signal that the system is not exe-cuting the desired instructions within the expected time frame. The watchdog output pulse can be used to reset the µP or interrupt the system to warn of processing errors.The MAX6369–MAX6374 are flexible watchdog timer supervisors that can increase system reliability through notification of code execution errors. The family offers several pin-selectable watchdog timing options to match a wide range of system timing applications:•Watchdog startup delay: provides an initial delay before the watchdog timer is started.•Watchdog timeout period: normal operating watch-dog timeout period after the initial startup delay.•Watchdog output/timing options: open drain (100ms)or push-pull (1ms).The MAX6369–MAX6374 operate over a +2.5V to +5.5V supply range and are available in miniature 8-pin SOT23 packages.________________________ApplicationsEmbedded Control Systems Industrial ControllersCritical µP and Microcontroller (µC) Monitoring AutomotiveTelecommunications NetworkingFeatures♦Precision Watchdog Timer for Critical µP Applications ♦Pin-Selectable Watchdog Timeout Periods ♦Pin-Selectable Watchdog Startup Delay Periods ♦Ability to Change Watchdog Timing Characteristics Without Power Cycling ♦Open-Drain or Push-Pull Pulsed Active-Low Watchdog Output ♦Watchdog Timer Disable Feature ♦+2.5V to +5.5V Operating Voltage ♦8µA Low Supply Current♦No External Components Required ♦Miniature 8-Pin SOT23 PackageMAX6369–MAX6374Pin-Selectable Watchdog Timers19-1676; Rev 3; 11/05Ordering InformationPin Configuration appears at end of data sheet.Note:All devices are available in tape-and-reel only. Required order increment is 2,500 pieces.Devices are available in both leaded and lead-free packaging.Specify lead-free by replacing “-T” with “+T” when ordering.Selector GuideFor pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at1-888-629-4642, or visit Maxim’s website at .M A X 6369–M A X 6374Pin-Selectable Watchdog Timers 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V CC = +2.5V to +5.5V, SET_ = V CC or GND, T A = -40°C to +85°C, unless otherwise noted. Typical values are at T A = +25°C andStresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Terminal Voltage (with respect to GND)V CC .....................................................................-0.3V to +6V WDI.....................................................................-0.3V to +6V WDO (Open Drain: MAX6369/71/73).................-0.3V to +6V WDO (Push-Pull: MAX6370/72/74 .......-0.3V to (V CC + 0.3V)SET0, SET1, SET2................................-0.3V to (V CC + 0.3V)Maximum Current, Any Pin (input/output)...........................20mAContinuous Power Dissipation (T A = +70°C)SOT23-8 (derate 8.75mW/°C above +70°C)...............700mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Junction Temperature......................................................+150°C Lead Temperature (soldering, 10s).................................+300°C V CC Rise or Fall Rate......................................................0.05V/µsMAX6369–MAX6374Pin-Selectable Watchdog Timers_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)M A X 6369–M A X 6374Pin-Selectable Watchdog Timers 4_______________________________________________________________________________________461081214-4010-15356085SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (µA )Typical Operating Characteristics(Circuit of Figure 1, T A = +25°C, unless otherwise noted .)0.9970.9990.9981.0011.0001.0021.003-4010-15356085WATCHDOG TIMEOUT PERIODvs. TEMPERATUREM A X 6369/74-02TEMPERATURE (°C)N O R M A L I Z E D W A T C H D O G T I M E O U T P E R I O DELECTRICAL CHARACTERISTICS (continued)Note 2:Guaranteed by design.Note 3:In this setting the watchdog timer is inactive and startup delay ends when WDI sees its first level transition. See SelectingDevice Timing for more information.Note 4:After power-up, or a setting change, there is an internal setup time during which WDI is ignored.MAX6369–MAX6374Pin-Selectable Watchdog Timers_______________________________________________________________________________________5Pin DescriptionDetailed DescriptionThe MAX6369–MAX6374 are flexible watchdog circuits for monitoring µP activity. During normal operation, the internal timer is cleared each time the µP toggles the WDI with a valid logic transition (low to high or high to low) within the selected timeout period (t WD ). The WDO remains high as long as the input is strobed within the selected timeout period. If the input is not strobed before the timeout period expires, the watchdog output is asserted low for the watchdog output pulse width (t WDO ). The device type and the state of the three logic control pins (SET0, SET1, and SET2) determine watch-dog timing characteristics. The three basic timing varia-tions for the watchdog startup delay and the normalTable 1 for the timeout characteristics for all devices in the family):•Watchdog Startup Delay:Provides an initial delay before the watchdog timer is started.Allows time for the µP system to power up and initial-ize before assuming responsibility for normal watch-dog timer updates.Includes several fixed or pin-selectable startup delay options from 200µs to 60s, and an option to wait for the first watchdog input transition before starting the watchdog timer.M A X 6369–M A X 6374Pin-Selectable Watchdog Timers 6_______________________________________________________________________________________•Watchdog Timeout Period:Normal operating watchdog timeout period after the initial startup delay.A watchdog output pulse is asserted if a valid watch-dog input transition is not received before the timeout period elapses.Eight pin-selectable timeout period options for each device, from 30µs to 60s.Pin-selectable watchdog timer disable feature.•Watchdog Output/Timing Options:Open drain, active low with 100ms minimum watch-dog output pulse (MAX6369/MAX6371/MAX6373).Push-pull, active low with 1ms minimum watchdog output pulse (MAX6370/MAX6372/MAX6374).Each device has a watchdog startup delay that is initi-ated when the supervisor is first powered or after the user modifies any of the logic control set inputs. The watchdog timer does not begin to count down until theFigure 1. Functional Diagramcompletion of the startup delay period, and no watch-dog output pulses are asserted during the startup delay. When the startup delay expires, the watchdog begins counting its normal watchdog timeout period and waiting for WDI transitions. The startup delay allows time for the µP system to power up and fully ini-tialize before assuming responsibility for the normal watchdog timer updates. Startup delay periods vary between the different devices and may be altered by the logic control set pins. To ensure that the system generates no undesired watchdog outputs, the routine watchdog input transitions should begin before the selected minimum startup delay period has expired. The normal watchdog timeout period countdown is initi-ated when the startup delay is complete. If a valid logic transition is not recognized at WDI before the watchdog timeout period has expired, the supervisor asserts a watchdog output. Watchdog timeout periods vary between the different devices and may be altered by the logic control set pins. To ensure that the system generates no undesired watchdog outputs, the watch-dog input transitions should occur before the selected minimum watchdog timeout period has expired.The startup delay and the watchdog timeout period are determined by the states of the SET0, SET1, and SET2 pins, and by the particular device within the family. For the MAX6369 and MAX6370, the startup delay is equal to the watchdog timeout period. The startup and watchdog timeout periods are pin selectable from 1ms to 60s (minimum).For the MAX6371 and MAX6372, the startup delay is fixed at 60s and the watchdog timeout period is pin selectable from 1ms to 60s (minimum).The MAX6373/MAX6374 provide two timing variations for the startup delay and normal watchdog timeout. Five of the pin-selectable modes provide startup delays from 200µs to 60s minimum, and watchdog timeout delays from 3ms to 10s minimum. Two of the selectable modes do not initiate the watchdog timer until the device receives its first valid watchdog input transition (there is no fixed period by which the first input must be received). These two extended startup delay modesare useful for applications requiring more than 60s for system initialization.All the MAX6369–MAX6374 devices may be disabledwith the proper logic control pin setting (Table 1).Applications InformationInput Signal Considerations Watchdog timing is measured from the last WDI risingor falling edge associated with a pulse of at least 100nsin width. WDI transitions are ignored when WDO is asserted, and during the startup delay period (Figure2). Watchdog input transitions are also ignored for asetup period, t SETUP, of up to 300µs after power-up ora setting change (Figure 3).Selecting Device TimingSET2, SET1, and SET0 program the startup delay and watchdog timeout periods (Table 1). Timeout settingscan be hard wired, or they can be controlled with logicgates and modified during operation. To ensure smooth transitions, the system should strobe WDI immediately before the timing settings are changed. This minimizesthe risk of initializing a setting change too late in thetimer countdown period and generating undesired watchdog outputs. After changing the timing settings,two outcomes are possible based on WDO. If the change is made while WDO is asserted, the previous setting is allowed to finish, the characteristics of thenew setting are assumed, and the new startup phase is entered after a 300µs setup time (t SETUP) elapses. Ifthe change is made while WDO is not asserted, thenew setting is initiated immediately, and the new start-up phase is entered after the 300µs setup time elapses.MAX6369–MAX6374Pin-Selectable Watchdog Timers_______________________________________________________________________________________7 Figure 3. Setting Change TimingM A X 6369–M A X 6374Pin-Selectable Watchdog TimersSelecting 011 (SET2 = 0, SET1 = 1, SET0 = 1) disables the watchdog timer function on all devices in the family.Operation can be reenabled without powering down by changing the set inputs to the new desired setting. The device assumes the new selected timing characteris-tics and enter the startup phase after the 300µs setup time elapses (Figure 3).The MAX6373/MAX6374 offer a first-edge feature. In first-edge mode (settings 101 or 110, Table 1), the internal timer does not control the startup delay period.Instead, startup terminates when WDI sees a transition.If changing to first-edge mode while the device is oper-ating, disable mode must be entered first. It is then safe to select first-edge mode. Entering disable mode first ensures the output is unasserted when selecting first-edge mode and removes the danger of WDI being masked out.OutputThe MAX6369/MAX6371/MAX6373 have an active-low,open-drain output that provides a watchdog output pulse of 100ms. This output structure sinks current when WDO is asserted. Connect a pullup resistor from WDO to any supply voltage up to +5.5V.Select a resistor value large enough to register a logic low (see Ele ctrical Characte ristics ), and small enoughto register a logic high while supplying all input current and leakage paths connected to the WDO line. A 10k Ωpullup is sufficient in most applications. The MAX6370/MAX6372/MAX6374 have push-pull outputs that pro-vide an active-low watchdog output pulse of 1ms.When WDO deasserts, timing begins again at the beginning of the watchdog timeout period (Figure 2).Usage in Noisy EnvironmentsIf using the watchdog timer in an electrically noisy envi-ronment, a bypass capacitor of 0.1µF should be con-nected between V CC and GND as close to the device as possible, and no further away than 0.2 inches.________________Watchdog SoftwareConsiderationsTo help the watchdog timer monitor software execution more closely, set and reset the watchdog input at differ-ent points in the program, rather than pulsing the watch-dog input high-low-high or low-high-low. This technique avoids a stuck loop, in which the watchdog timer would continue to be reset inside the loop, keeping the watch-dog from timing out. Figure 4 shows an example of a flow diagram where the I/O driving the watchdog input is set high at the beginning of the program, set low at the end of every subroutine or loop, then set high again when the program returns to the beginning. If the pro-gram should hang in any subroutine, the problem would be quickly corrected, since the I/O is continually set low and the watchdog timer is allowed to time out, causing WDO to pulse.Figure 4. Watchdog Flow DiagramChip InformationTRANSISTOR COUNT: 1500PROCESS: BiCMOSPin ConfigurationMaxim cannot assume re sponsibility for use of any circuitry othe r than circuitry e ntire ly e mbodie d in a Maxim product. No circuit pate nt lice nse s are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.8_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©2005 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products, Inc.。

蜚声功放说明书

4. 信号指示灯此指示灯指示该通道的输出电平，亮度随输出电平幅度的大小变化而变化。
5. 安装孔用于安装到机柜时固定用。
6. 通道1的音量控制器功放工作于立体声或并接模式时由此控制器控制通道1的输出电平，功放工作于桥接模式时由此控制器控制输出电平，此时通道2的音量控制器失效。
7. 保护指示当此指示灯亮，处于保护状态，方便找出问题所在。指示的保护功能有：削峰压限保护、过热保护、过载保护、短路保护、直流保护功能。
11电压增益频率响应总谐波失真转换速率阻尼系数动态范围信噪比输入灵敏度输入阻抗平衡不平衡输出级电路类型保护功能高通滤波器低通滤波器散热气流方向输入电压频率外箱尺寸mm重量压限直流短路开关机零冲击开机软启动vhf甚高频保护压限直流短路开关机零冲击开机软启动从功放面板进风23kg29kg29kg33kg35kg38kg33kgl620xw585xh210max1200max2400max3600max4300max7200max7800650wx21250wx2450wx2675wx2800wx2975wx21650wx21950wx2520wx2450wx2300wx21100wx2max4800830wx21250wx2900w1350w1600w1950w3300w3900w2500w620wx21000wx21200wx21400wx22160wx22700wx21850wx2桥接功率1240w2000w2400w2800w43200w5400w3700wmax系列技术参数12注意
2. TRS输入座(平衡或不平衡)。连接到上一级的周边处理设备。 3. 直通插座
与XLR 输入并联，提供一个与输入信号一样的输出信号，用此平衡插座连接到另一台设备。（仅限于MAX4300、MAX4800、MAX7200、MAX7800） 4. 输入灵敏度开关此开关用于选择功放的输入灵敏度：0.775V、1.0V及1.4V。(仅限于MAX4300、MAX4800、MAX7200、 MAX7800）。 5. 工作模式选择开关用此开关去选择功放的工作模式： STEREO/立体声：两个通道完全独立。 PARALLEL/并接：信号共用通道1输入，音量独立控制，输出独立。 BRIDGE/桥接：信号共用通道1输入，音量由通道1控制，输出接通道1的SPEAKON。当使用到该工作模式时，背板的指示灯亮。注意：具体见下页的接线图。 6. 150Hz低通滤波器开关若系统中需要推动超低音的音箱时，将开关拨到“ON”的位置可以滤掉150Hz以上的信号，直接使用功放推动超低音的音箱，无需外加电子分频器。(仅限于MAX4300、MAX4800、MAX7200、MAX7800) 7. 音箱螺旋座输出这是功放螺旋座的输出端。1+接喇叭的正端，1-接喇叭的负端，桥接时1+接喇叭的正端、2+接喇叭的负端。 8. 喇叭接线柱输出这是功放喇叭接线柱的输出端。红色接喇叭的正端，黑色接喇叭的负端，桥接时只使用红色接喇叭的正端。 9. 保险管座此保险管座内装由标准规格的保险管，用于故障时保护功放，如果功放已经接上电源待机指示灯没有点亮时，请检查保险管的情况，如发现保险管已熔掉，在故障排除后，必须更换同一规格的保险管。 10. 散热的气流入口，不要有任何东西堵住。

MAX6389XS29D4+T中文资料

General Description The MAX6381–MAX6390 microprocessor (µP) supervisory circuits monitor power-supply voltages from +1.8V to +5.0V while consuming only 3µA of supply current at +1.8V. Whenever V CC falls below the factory-set reset thresholds, the reset output asserts and remains assert-ed for a minimum reset timeout period after V CC rises above the reset threshold. Reset thresholds are available from +1.58V to +4.63V, in approximately 100mV incre-ments. Seven minimum reset timeout delays ranging from 1ms to 1200ms are available.The MAX6381/MAX6384/MAX6387 have a push-pull active-low reset output. The MAX6382/MAX6385/ MAX6388 have a push-pull active-high reset output, and the MAX6383/MAX6386/MAX6389/MAX6390 have an open-drain active-low reset output. The MAX6384/MAX6385/MAX6386 also feature a debounced manual reset input (with internal pullup resistor). The MAX6387/MAX6388/MAX6389 have an auxiliary input for monitoring a second voltage. The MAX6390 offers a manual reset input with a longer V CC reset timeout period (1120ms or 1200ms) and a shorter manual reset timeout (140ms or 150ms).The MAX6381/MAX6382/MAX6383 are available in 3-pin SC70 and6-pinµDFN packages and the MAX6384–MAX6390 are available in 4-pin SC70 andFeatures♦Factory-Set Reset Threshold Voltages Rangingfrom +1.58V to +4.63V in Approximately 100mVIncrements♦±2.5% Reset Threshold Accuracy OverTemperature (-40°C to +125°C)♦Seven Reset Timeout Periods Available: 1ms,20ms, 140ms, 280ms, 560ms, 1120ms,1200ms (min)♦3 Reset Output OptionsActive-Low Push-PullActive-High Push-PullActive-Low Open-Drain♦Reset Output State Guaranteed ValidDown to V CC= 1V♦Manual Reset Input (MAX6384/MAX6385/MAX6386)♦Auxiliary RESET IN(MAX6387/MAX6388/MAX6389)♦V CC Reset Timeout (1120ms or 1200ms)/ManualReset Timeout (140ms or 150ms) (MAX6390)♦Negative-Going V CC Transient Immunity♦Low Power Consumption of 6µA at +3.6Vand 3µA at +1.8V♦Pin Compatible withMAX809/MAX810/MAX803/MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX6348,and MAX6711/MAX6712/MAX6713♦Tiny 3-Pin/4-Pin SC70 and 6-Pin µDFN PackagesMAX6381–MAX6390 SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits ________________________________________________________________Maxim Integrated Products1Pin Configurations19-1839; Rev 4; 4/07Ordering InformationOrdering Information continued at end of data sheet.Typi cal Operati ng Ci rcui t appears at end of data sheet.Selector Guide appears at end of data sheet.after "XR", "XS", or "LT." Insert reset timeout delay (see ResetTimeout Delay table) after "D" to complete the part number.Sample stock is generally held on standard versions only (seeStandard Versions table). Standard versions have an orderincrement requirement of 2500 pieces. Nonstandard versionshave an order increment requirement of 10,000 pieces.Contact factory for availability of nonstandard versions.+Denotes a lead-free package.For pricing, delivery, and ordering information,please contact Maxim Direct at 1-888-629-4642,or visit Maxim’s website at .ComputersControllersIntelligent InstrumentsCritical µP and µCPower MonitoringPortable/Battery-Powered EquipmentDual Voltage SystemsM A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V CC = full range, T A = -40°C to +125°C, unless otherwise specified. Typical values are at T A = +25°C.) (Note 1)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.V CC to GND..........................................................-0.3V to +6.0V RESET Open-Drain Output....................................-0.3V to +6.0V RESET , RESET (push-pull output)..............-0.3V to (V CC + 0.3V)MR , RESET IN.............................................-0.3V to (V CC + 0.3V)Input Current (V CC ).............................................................20mA Output Current (all pins).....................................................20mAContinuous Power Dissipation (T A = +70°C)3-Pin SC70 (derate 2.9mW/°C above +70°C)..............235mW 4-Pin SC70 (derate 3.1mW/°C above +70°C)..............245mW 6-Pin µDFN (derate 2.1mW/°C above +70°C)..........167.7mW Operating Temperature Range .........................-40°C to +125°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°CMAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits_______________________________________________________________________________________3M A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 4______________________________________________________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)215436789-40-105-25203550658095110125SUPPLY CURRENT vs. TEMPERATURE(NO LOAD)TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )25292735333137394143-40-105-25203550658095110125POWER-DOWN RESET DELAYvs. TEMPERATURETEMPERATURE (°C)P O W E R -D O W N R E S E T D E L A Y (µs )0.940.980.961.021.001.061.041.08-40-10520-253550658095110125NORMALIZED POWER-UP RESET TIMEOUTvs. TEMPERATUREM A X 6381/90 t o c 03TEMPERATURE (°C)N O R M A L I Z E D R E S E T T I M E O U T P E R I O D0.9900.9851.0150.9950.9901.0001.0051.0101.020-40-10520-253550958011065125M A X 6381/90 t o c 04TEMPERATURE (°C)N O R M A L I Z E D R E S E T TH R E S H O L D NORMALIZED RESET THRESHOLDvs. TEMPERATURE00.40.20.80.61.01.2063912OUTPUT-VOLTAGE LOW vs. SINK CURRENTI SINK (mA)V O L (V )01.00.52.01.52.53.00500750250100012501500OUTPUT-VOLTAGE HIGH vs. SOURCE CURRENTI SOURCE (µA)V O H (V )45001100010010MAXIMUM TRANSIENT DURATION vs. RESET COMPARATOR OVERDRIVE15050350250500200100400300RESET COMPARATOR OVERDRIVE, V TH - V CC (mV)M A X I M U M T R A N S I E N T D U R A T I O N (µs )3.53.93.74.54.34.14.74.95.35.15.5-40-105-25203550658095110125RESET IN TO RESET DELAYvs. TEMPERATUREM A X 6381/90 t o c 08TEMPERATURE (°C)R E S E T I N D E L A Y (µs )MAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset CircuitsPin DescriptionM A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 6_______________________________________________________________________________________Detailed DescriptionRESET OutputA µP reset input starts the µP in a known state. These µP supervisory circuits assert reset to prevent code execution errors during power-up, power-down, or brownout conditions.Reset asserts when V CC is below the reset threshold;once V CC exceeds the reset threshold, an internal timer keeps the reset output asserted for the reset timeout period. After this interval, reset output deasserts. Reset output is guaranteed to be in the correct logic state for V CC ≥1V.Manual Reset Input (MAX6384/MAX6385/MAX6386/MAX6390)Many µP-based products require manual reset capabil-ity, allowing the operator, a test technician, or external logic circuitry to initiate a reset. A logic low on MR asserts reset. Reset remains asserted while MR is low,and for the reset active timeout period (t RP ) after MR returns high. This input has an internal 63k Ωpullup resistor (1.56k Ωfor MAX6390), so it can be left uncon-nected if it is not used. MR can be driven with TTL or CMOS logic levels, or with open-drain/collector outputs.Connect a normally open momentary switch from MR to G ND to create a manual-reset function; external debounce circuitry is not required. If MR is driven from long cables or if the device is used in a noisy environ-ment, connecting a 0.1µF capacitor from MR to G ND provides additional noise immunity.RESET IN Comparator(MAX6387/MAX6388/MAX6389)RESET IN is compared to an internal +1.27V reference.If the voltage at RESET IN is less than 1.27V, reset asserts. Use the RESET IN comparator as a user-adjustable reset detector or as a secondary power-sup-ply monitor by implementing a resistor-divider at RESET IN (shown in Figure 1). Reset asserts when either V CC or RESET IN falls below its respective threshold volt-age. Use the following equation to set the threshold:V INTH = V THRST (R1/R2 + 1)where V THRST = +1.27V. To simplify the resistor selec-tion, choose a value of R2 and calculate R1:R1 = R2 [(V INTH /V THRST ) - 1]Since the input current at RESET IN is 50nA (max),large values can be used for R2 with no significant loss in accuracy.___________Applications InformationNegative-Going V CC TransientsIn addition to issuing a reset to the µP during power-up,power-down, and brownout conditions, the MAX6381–MAX6390 are relatively immune to short dura-tion negative-going V CC transients (glitches).The Typical Operating Characteristics section shows the Maximum Transient Durations vs. Reset Comparator Overdrive, for which the MAX6381–MAX6390 do not generate a reset pulse. This graph was generated usinga negative-going pulse applied to V CC , starting above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). The graph indicates the typical maximum pulse width a neg-ative-going V CC transient may have without causing a reset pulse to be issued. As the magnitude of the tran-sient increases (goes farther below the reset threshold),the maximum allowable pulse width decreases. A 0.1µF capacitor mounted as close as possible to V CC provides additional transient immunity.Ensuring a Valid RESET Output Down to V CC = 0VThe MAX6381–MAX6390 are guaranteed to operate properly down to V CC = 1V. In applications that require valid reset levels down to V CC = 0V, a pulldown resistor to active-low outputs (push/pull only, Figure 2) and a pullup resistor to active-high outputs (push/pull only)will ensure that the reset line is valid while the reset out-put can no longer sink or source current. This schemedoes not work with the open-drain outputs of the MAX6383/MAX6386/MAX6389/MAX6390. The resistor value used is not critical, but it must be small enough not to load the reset output when V CC is above the reset threshold. For most applications, 100k Ωis ade-quate.MAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits_______________________________________________________________________________________7M A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 8_______________________________________________________________________________________Selector GuideOrdering Information (continued)Note:Insert reset threshold suffix (see Reset Threshold table)after "XR", "XS", or "LT." Insert reset timeout delay (see Reset Timeout Delay table) after "D" to complete the part number.Sample stock is generally held on standard versions only (see Standard Versions table). Standard versions have an order increment requirement of 2500 pieces. Nonstandard versions have an order increment requirement of 10,000 pieces.Contact factory for availability of nonstandard versions.*MAX6390 is available with D4 or D7 timing only.+Denotes a lead-free package.MAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits_______________________________________________________________________________________9Chip InformationTRANSISTOR COUNT: 647PROCESS: BiCMOSPin Configurations (continued)M A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 10______________________________________________________________________________________Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /packages .)MAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits______________________________________________________________________________________11Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /packages .)M A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 12______________________________________________________________________________________Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /packages .)SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset CircuitsMaxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600____________________13©2007 Maxim Integrated Productsis a registered trademark of Maxim Integrated Products, Inc.MAX6381–MAX6390Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /packages .)Revision HistoryPages changed at Rev 4: Title on all pages, 1, 2, 5,7–13。

MAX6368LKA23-T中文资料

General DescriptionThe MAX6365–MAX6368 supervisory circuits simplify power-supply monitoring, battery-backup control func-tions, and memory write protection in microprocessor (µP) systems. The circuits significantly improve the size,accuracy, and reliability of modern systems with an ultra-small integrated solution.These devices perform four basic system functions:1) Provide a µP reset output during V CC supply power-up, power-down, and brownout conditions.2) Internally control V CC to backup-battery switching tomaintain data or low-power operation for CMOS RAM, CMOS µPs, real-time clocks, and other digital logic when the main supply fails.3) Provide memory write protection through internalchip-enable gating during supply or processor faults.4) Include one of the following options: a manual resetinput (MAX6365), a watchdog timer function (MAX6366), a battery-on output (MAX6367), or an auxiliary user-adjustable reset input (MAX6368).The MAX6365–MAX6368 operate from V CC supply volt-ages as low as 1.2V. The factory preset reset threshold voltages range from 2.32V to 4.63V (see Ordering Information ). In addition, each part is offered in three reset output versions: push-pull active low, open-drain active low, or open-drain active high (see Selector Guide ). The MAX6365–MAX6368 are available in minia-ture 8-pin SOT23 packages.ApplicationsCritical µP/µC Power Portable/Battery-Monitoring Powered Equipment Fax Machines Set-Top Boxes Industrial Control POS EquipmentComputers/ControllersFeatureso Low +1.2V Operating Supply Voltage (V CC or V BATT )o Precision Monitoring of +5.0V, +3.3V, +3.0V, and +2.5V Power-Supply Voltageso On-Board Gating of Chip-Enable Signals, 1.5ns Propagation Delayo Debounced Manual Reset Input (MAX6365)o Watchdog Timer, 1.6s Timeout (MAX6366)o Battery-On Output Indicator (MAX6367)o Auxiliary User-Adjustable RESET IN (MAX6368)o Low 10µA Quiescent Supply Current o Three Available Output StructuresPush-Pull RESET Open-Drain RESET Open-Drain RESETo RESET/RESET Valid Down to 1.2V Guaranteed (V CC or V BATT )o Power-Supply Transient Immunity o 150ms min Reset Timeout Period o Miniature 8-Pin SOT23 PackageMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating________________________________________________________________Maxim Integrated Products1Pin Configurations19-1658; Rev 1; 6/01For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .Ordering Information*These parts offer a choice of reset threshold voltages. From the Reset Threshold Ranges table, insert the desired threshold volt-age code in the blank to complete the part number. SOT parts come in tape-and-reel only and must be ordered in 2500-piece increments. See Device Marking Codes for a complete parts list,including SOT top marks and standard threshold versions. See Selector Guide for a listing of device features.Typical Operating Circuit appears at end of data sheet.M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable GatingABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V = +2.4V to +5.5V, V = +3.0V, CE IN = V , reset not asserted, T = -40°C to +85°C. Typical values are at T = +25°C,Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Terminal Voltages (with respect to GND)V CC , BATT, OUT.......................................................-0.3V to +6V RESET (open drain), RESET (open drain)................-0.3V to +6V BATT ON, RESET (push-pull), RESET IN,WDI, CE IN, CE OUT...........................-0.3V to (V OUT + 0.3V)MR ..............................................................-0.3V to (V CC + 0.3V)Input CurrentV CC Peak ..............................................................................1A V CC Continuous.............................................................250mA BATT Peak.....................................................................250mA BATT Continuous.............................................................40mAGND...............................................................................75mA Output CurrentOUT...............................Short-Circuit Protected for up to 10s RESET, RESET , BATT ON, CE OUT...............................20mA Continuous Power Dissipation (T A = +70°C)8-Pin SOT23 (derate 8.75mW/°C above +70°C)........700mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Junction Temperature .....................................................+150°C Lead Temperature (soldering, 10s).................................+300°CMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)(V CC = +2.4V to +5.5V, V BATT = +3.0V, CE IN = V CC , reset not asserted, T A = -40°C to +85°C. Typical values are at T A = +25°C,M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 4_______________________________________________________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)8109121115141316-400-2020406080SUPPLY CURRENTvs. TEMPERATURE (NO LOAD)TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )0.20.60.40.81.01.2BATTERY SUPPLY CURRENT (BACKUP MODE) vs. TEMPERATURETEMPERATURE (°C)B A T T E R Y S U P P L YC U R R E N T (µA )-402040-200608021437658-40-2020406080BATT-TO-OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)B A T T -T O -O U T O N -R E S I S T A NC E (Ω)ELECTRICAL CHARACTERISTICS (continued)(V= +2.4V to +5.5V, V = +3.0V, CE IN = V , reset not asserted, T = -40°C to +85°C. Typical values are at T = +25°C,Note 2:V BATT can be 0 anytime, or V CC can go down to 0 if V BATT is active (except at startup).Note 3:RESET is pulled up to OUT. Specifications apply for OUT = V CC or OUT = BATT.Note 4:The chip-enable resistance is tested with V CC = V TH(MAX)and CE IN = V CC /2.MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________5Typical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)00.40.20.80.61.21.01.4-4020-20406080V CC TO OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)V C C T O O U T O N -R E S I S T A N C E (Ω)190195205200210RESET TIMEOUT PERIOD vs. TEMPERATUREM A X 6365/8-05TEMPERATURE (°C)R E S E T T I M E O U T P E R I O D (m s )-402040-206080301575604513512010590TEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )-402040-206080V CC vs. TEMPERATURE2.03.02.55.04.54.03.5RESET THRESHOLD vs. TEMPERATURETEMPERATURE (°C)T H R E S H O L D (V )-402040-206080110010100010,000MAXIMUM TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVERESET THRESHOLD OVERDRIVE V TH - V CC (mV)M A X I M U M T R A N S I E N T D U R A T I O N (µs )40030035025020005015010003215498761000.5 1.0 1.5 2.0 2.5 3.0 3.5BATTERY SUPPLY CURRENT vs. SUPPLY VOLTAGEV CC (V)B A T T E R Y S U P P L YC U R R E N T (µA )M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 6_______________________________________________________________________________________1.2341.2351.236MAX6368RESET IN THRESHOLD vs. TEMPERATUREM A X 6365/8 -10TEMPERATURE (°C)V R T H (V )-402040-2060801.01.91.61.32.82.52.2MAX6368RESET IN TO RESET PROPAGATION DELAYvs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )-402040-206080013245C LOAD (pF)P R O P A G A T I O N D E L A Y (n s )10050150200CHIP-ENABLE PROPAGATION DELAY vs. CE OUT LOAD CAPACITANCE515102025-40-2020406080TEMPERATURE (°C)C E I N T O C E O U T O N -R E S I S T A N C E (Ω)CE IN TO CE OUT ON-RESISTANCEvs. TEMPERATURE1.01.31.21.11.51.41.91.81.71.62.0-40-2020406080TEMPERATURE (°C)W A T C H D O G T I M E O U T P E R I O D (s )MAX6366WATCHDOG TIMEOUT PERIODvs. TEMPERATURETypical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________7M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 8_______________________________________________________________________________________Detailed DescriptionThe Typical Operating Circuit shows a typical connec-tion for the MAX6365–MAX6368. OUT powers the static random-access memory (SRAM). If V CC is greater than the reset threshold (V TH ), or if V CC is lower than V TH but higher than V BATT , V CC is connected to OUT. If V CC is lower than V TH and V CC is less than V BATT ,BATT is connected to OUT. OUT supplies up to 150mA from V CC . In battery-backup mode, an internal MOSFET connects the backup battery to OUT. The on-resistance of the MOSFET is a function of backup-battery voltage and is shown in the BATT-to-OUT On-Resistance vs.Temperature graph in the T ypical Operating Char-acteristics .Chip-Enable Signal GatingThe MAX6365–MAX6368 provide internal gating of CE signals to prevent erroneous data from being written toCMOS RAM in the event of a power failure. During nor-mal operation, the CE gate is enabled and passes all CE transitions. When reset asserts, this path becomes disabled, preventing erroneous data from corrupting the CMOS RAM. All of these devices use a series trans-mission gate from CE IN to CE OUT. The 2ns propaga-tion delay from CE IN to CE OUT allows the devices to be used with most µPs and high-speed DSPs.During normal operation, CE IN is connected to CE OUT through a low on-resistance transmission gate.This is valid when reset is not asserted. If CE IN is high when reset is asserted, CE OUT remains high regard-less of any subsequent transitions on CE IN during the reset event.If CE IN is low when reset is asserted, CE OUT is held low for 12µs to allow completion of the read/write oper-ation (F igure 1). After the 12µs delay expires, the CEFunctional DiagramMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________9OUT goes high and stays high regardless of any sub-sequent transitions on CE IN during the reset event.When CE OUT is disconnected from CE IN, CE OUT is actively pulled up to OUT.The propagation delay through the chip-enable circuit-ry depends on both the source impedance of the drive to CE IN and the capacitive loading at CE OUT. The chip-enable propagation delay is production tested from the 50% point of CE IN to the 50% point of CE OUT, using a 50Ωdriver and 50pF load capacitance.Minimize the capacitive load at CE OUT to minimize propagation delay, and use a low-output-impedance driver.Backup-Battery SwitchoverIn a brownout or power failure, it may be necessary to preserve the contents of the RAM. With a backup bat-tery installed at BATT, the MAX6365–MAX6368 auto-matically switch the RAM to backup power when V CC falls. The MAX6367 has a BATT ON output that goes high in battery-backup mode. These devices require two conditions before switching to battery-backup mode:1) V CC must be below the reset threshold.2) V CC must be below V BATT .Table 1 lists the status of the inputs and outputs in bat-tery-backup mode. The devices do not power up if theonly voltage source is on BATT. OUT only powers up from V CC at startup.Many µP-based products require manual reset capabili-ty, allowing the user or external logic circuitry to initiate a reset. For the MAX6365, a logic low on MR asserts reset.Reset remains asserted while MR is low and for a mini-mum of 150ms (t RP ) after it returns high. MR has an inter-nal 20k Ωpullup resistor to V CC . This input can be driven with TTL/CMOS logic levels or with open-drain/collector outputs. Connect a normally open momentary switch from MR to GND to create a manual reset function; exter-nal debounce circuitry is not required. If MR is driven from long cables or the device is used in a noisy environ-ment, connect a 0.1µF capacitor from MR to GND to pro-vide additional noise immunity.Figure 1. Reset and Chip-Enable TimingM A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 10______________________________________________________________________________________Watchdog Input (MAX6366 Only)The watchdog monitors µP activity through the watch-dog input (WDI). If the µP becomes inactive, reset asserts. To use the watchdog function, connect WDI to a bus line or µP I/O line. A change of state (high to low,low to high, or a minimum 100ns pulse) resets the watchdog timer. If WDI remains high or low for longer than the watchdog timeout period (t WD ), the internal watchdog timer runs out and a reset pulse is triggered for the reset timeout period (t RP ). The internal watchdog timer clears whenever reset asserts or whenever WDI sees a rising or falling edge. If WDI remains in either a high or low state, a reset pulse asserts periodically after every t WD (F igure 2). Leave WDI unconnected to dis-able the watchdog function.BATT ON Indicator (MAX6367 Only)BATT ON is a push-pull output that drives high when in battery-backup mode. BATT ON typically sinks 3.2mA at 0.1V saturation voltage. In battery-backup mode, this terminal sources approximately 10µA from OUT. Use BATT ON to indicate battery-switchover status or to supply base drive to an external pass transistor for higher current applications (Figure 3).RESET IN Comparator (MAX6368 Only)RESET IN is compared to an internal 1.235V reference.If the voltage at RESET IN is less than 1.235V, reset asserts. Use the RESET IN comparator as an undervolt-age detector to signal a failing power supply or as a secondary power-supply reset monitor.To program the reset threshold (V RTH ) of the secondary power supply, use the following (see Typical Operating Circuit ):V RTH = V REF (R1 / R2 + 1)where V REF = 1.235V. To simplify the resistor selection,choose a value for R2 and calculate R1:R1 = R2 [(V RTH / V REF ) - 1]Since the input current at RESET IN is 25nA (max),large values (up to 1M Ω) can be used for R2 with no significant loss in accuracy. For example, in the Typical Operating Circuit , the MAX6368 monitors two supply voltages. To monitor the secondary 5V logic or analog supply with a 4.60V nominal programmed reset thresh-old, choose R2 = 100k Ω, and calculate R1 = 273k Ω.Reset OutputA µP ’s reset input starts the µP in a known state. The MAX6365–MAX6368 µP supervisory circuits assert a reset to prevent code-execution errors during power-up, power-down, and brownout conditions. RESET is guaranteed to be a logic low or logic high, depending on the device chosen (see Ordering Information ).RESET or RESET asserts when V CC is below the reset threshold and for at least 150ms (t RP ) after V CC rises above the reset threshold. RESET or RESET also asserts when MR is low (MAX6365) and when RESET IN is less than 1.235V (MAX6368). The MAX6366 watch-dog function will cause RESET (or RESET ) to assert in pulses following a watchdog timeout (Figure 2).Applications InformationOperation Withouta Backup Power SourceThe MAX6365–MAX6368 provide battery-backup func-tions. If a backup power source is not used, connect BATT to GND and OUT to V CC .Watchdog Software ConsiderationsOne way to help the watchdog timer monitor the soft-ware execution more closely is to set and reset the watchdog at different points in the program rather than pulsing the watchdog input periodically. F igure 4shows a flow diagram in which the I/O driving theFigure 2. MAX6366 Watchdog Timeout Period and Reset Active TimeMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating______________________________________________________________________________________11watchdog is set low in the beginning of the program,set high at the beginning of every subroutine or loop,and set low again when the program returns to the beginning. If the program should hang in any subrou-tine, the problem would be quickly corrected.Replacing the Backup BatteryWhen V CC is above V TH , the backup power source can be removed without danger of triggering a reset pulse.The device does not enter battery-backup mode when V CC stays above the reset threshold voltage.Negative-Going V CC TransientsThese supervisors are relatively immune to short-dura-tion, negative-going V CC transients. Resetting the µP when V CC experiences only small glitches is usually not desirable.The T ypical Operating Characteristics section has a Maximum Transient Duration vs. Reset Threshold Overdrive graph for which reset is not asserted. The graph was produced using negative-going V CC pulses,starting at V CC and ending below the reset threshold by the magnitude indicated (reset threshold overdrive).The graph shows the maximum pulse width that a neg-ative-going V CC transient can typically have without triggering a reset pulse. As the amplitude of the tran-sient increases (i.e., goes further below the reset threshold), the maximum allowable pulse width decreases. Typically, a V CC transient that goes 100mV below the reset threshold and lasts for 30µs will not trig-ger a reset pulse.A 0.1µF bypass capacitor mounted close to the V CC pin provides additional transient immunity.M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 12______________________________________________________________________________________standard versions only. Contact factory for availability of nonstandard versions.MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating______________________________________________________________________________________13Pin Configurations (continued)M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 14______________________________________________________________________________________Typical Operating CircuitChip InformationTRANSISTOR COUNT: 729PROCESS: CMOSSOT23, Low-Power µP Supervisory Circuitswith Battery Backup and Chip-Enable GatingMAX6365–MAX6368Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________15©2001 Maxim Integrated Products Printed USAis a registered trademark of Maxim Integrated Products.Package Information。

MAX238CWG+T中文资料

General DescriptionThe MAX220–MAX249 family of line drivers/receivers is intended for all EIA/TIA-232E and V.28/V.24 communica-tions interfaces, particularly applications where ±12V is not available.These parts are especially useful in battery-powered sys-tems, since their low-power shutdown mode reduces power dissipation to less than 5µW. The MAX225,MAX233, MAX235, and MAX245/MAX246/MAX247 use no external components and are recommended for appli-cations where printed circuit board space is critical.________________________ApplicationsPortable Computers Low-Power Modems Interface TranslationBattery-Powered RS-232 Systems Multidrop RS-232 NetworksNext-Generation Device Features♦For Low-Voltage, Integrated ESD ApplicationsMAX3222E/MAX3232E/MAX3237E/MAX3241E/MAX3246E: +3.0V to +5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Using Four 0.1µF External Capacitors (MAX3246E Available in a UCSP™Package)♦For Low-Cost ApplicationsMAX221E: ±15kV ESD-Protected, +5V, 1µA,Single RS-232 Transceiver with AutoShutdown™MAX220–MAX249+5V-Powered, Multichannel RS-232Drivers/Receivers________________________________________________________________Maxim Integrated Products 1Selection Table19-4323; Rev 15; 1/06Power No. of NominalSHDN RxPart Supply RS-232No. of Cap. Value & Three-Active in Data Rate Number (V)Drivers/Rx Ext. Caps (µF)State SHDN (kbps)FeaturesMAX220+52/240.047/0.33No —120Ultra-low-power, industry-standard pinout MAX222+52/2 4 0.1Yes —200Low-power shutdownMAX223 (MAX213)+54/54 1.0 (0.1)Yes ✔120MAX241 and receivers active in shutdown MAX225+55/50—Yes ✔120Available in SOMAX230 (MAX200)+55/04 1.0 (0.1)Yes —120 5 drivers with shutdownMAX231 (MAX201)+5 and2/2 2 1.0 (0.1)No —120Standard +5/+12V or battery supplies; +7.5 to +13.2same functions as MAX232MAX232 (MAX202)+52/24 1.0 (0.1)No —120 (64)Industry standardMAX232A+52/240.1No —200Higher slew rate, small caps MAX233 (MAX203)+52/20— No —120No external capsMAX233A+52/20—No —200No external caps, high slew rate MAX234 (MAX204)+54/04 1.0 (0.1)No —120Replaces 1488MAX235 (MAX205)+55/50—Yes —120No external capsMAX236 (MAX206)+54/34 1.0 (0.1)Yes —120Shutdown, three stateMAX237 (MAX207)+55/34 1.0 (0.1)No —120Complements IBM PC serial port MAX238 (MAX208)+54/44 1.0 (0.1)No —120Replaces 1488 and 1489MAX239 (MAX209)+5 and3/52 1.0 (0.1)No —120Standard +5/+12V or battery supplies;+7.5 to +13.2single-package solution for IBM PC serial port MAX240+55/54 1.0Yes —120DIP or flatpack package MAX241 (MAX211)+54/54 1.0 (0.1)Yes —120Complete IBM PC serial port MAX242+52/240.1Yes ✔200Separate shutdown and enableMAX243+52/240.1No —200Open-line detection simplifies cabling MAX244+58/104 1.0No —120High slew rateMAX245+58/100—Yes ✔120High slew rate, int. caps, two shutdown modes MAX246+58/100—Yes ✔120High slew rate, int. caps, three shutdown modes MAX247+58/90—Yes ✔120High slew rate, int. caps, nine operating modes MAX248+58/84 1.0Yes ✔120High slew rate, selective half-chip enables MAX249+56/1041.0Yes✔120Available in quad flatpack packageFor pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .Ordering InformationOrdering Information continued at end of data sheet.*Contact factory for dice specifications.AutoShutdown and UCSP are trademarks of Maxim Integrated Products, Inc.M A X 220–M A X 249+5V-Powered, Multichannel RS-232Drivers/Receivers 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGS—MAX220/222/232A/233A/242/243ELECTRICAL CHARACTERISTICS—MAX220/222/232A/233A/242/243Note 1:For the MAX220, V+ and V- can have a maximum magnitude of 7V, but their absolute difference cannot exceed 13V.Note 2:Input voltage measured with T OUT in high-impedance state, SHDN or V CC = 0V.Note 3:Maximum reflow temperature for the MAX233A is +225°C.Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Supply Voltage (V CC )...............................................-0.3V to +6V V+ (Note 1)..................................................(V CC - 0.3V) to +14V V- (Note 1).............................................................+0.3V to +14V Input VoltagesT IN ..............................................................-0.3V to (V CC - 0.3V)R IN (Except MAX220)........................................................±30V R IN (MAX220).....................................................................±25V T OUT (Except MAX220) (Note 2).......................................±15V T OUT (MAX220)...............................................................±13.2V Output VoltagesT OUT ...................................................................................±15V R OUT .........................................................-0.3V to (V CC + 0.3V)Driver/Receiver Output Short Circuited to GND.........Continuous Continuous Power Dissipation (T A = +70°C)16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)..842mW18-Pin Plastic DIP (derate 11.11mW/°C above +70°C)..889mW 20-Pin Plastic DIP (derate 8.00mW/°C above +70°C)..440mW 16-Pin Narrow SO (derate 8.70mW/°C above +70°C)...696mW 16-Pin Wide SO (derate 9.52mW/°C above +70°C)......762mW 18-Pin Wide SO (derate 9.52mW/°C above +70°C)......762mW 20-Pin Wide SO (derate 10.00mW/°C above +70°C)....800mW 20-Pin SSOP (derate 8.00mW/°C above +70°C)..........640mW 16-Pin CERDIP (derate 10.00mW/°C above +70°C).....800mW 18-Pin CERDIP (derate 10.53mW/°C above +70°C).....842mW Operating Temperature RangesMAX2_ _AC_ _, MAX2_ _C_ _.............................0°C to +70°C MAX2_ _AE_ _, MAX2_ _E_ _..........................-40°C to +85°C MAX2_ _AM_ _, MAX2_ _M_ _.......................-55°C to +125°C Storage Temperature Range.............................-65°C to +160°C Lead Temperature (soldering, 10s) (Note 3)...................+300°CMAX220–MAX249+5V-Powered, Multichannel RS-232Drivers/Receivers_______________________________________________________________________________________3Note 4:MAX243 R2OUT IN ELECTRICAL CHARACTERISTICS—MAX220/222/232A/233A/242/243 (continued)M A X 220–M A X 249+5V-Powered, Multichannel RS-232Drivers/Receivers 4_________________________________________________________________________________________________________________________________Typical Operating CharacteristicsMAX220/MAX222/MAX232A/MAX233A/MAX242/MAX243108-1051525OUTPUT VOLTAGE vs. LOAD CURRENT-4-6-8-2642LOAD CURRENT (mA)O U T P U T V O L T A G E (V )1002011104104060AVAILABLE OUTPUT CURRENTvs. DATA RATE65798DATA RATE (kb/s)O U T P U T C U R R E N T (m A )203050+10V-10VMAX222/MAX242ON-TIME EXITING SHUTDOWN+5V +5V 0V0V 500μs/div V +, V - V O L T A G E (V )ELECTRICAL CHARACTERISTICS—MAX220/222/232A/233A/242/243 (continued)(V CC = +5V ±10%, C1–C4 = 0.1µF‚ MAX220, C1 = 0.047µF, C2–C4 = 0.33µF, T A = T MIN to T MAX ‚ unless otherwise noted.)MAX220–MAX249+5V-Powered, Multichannel RS-232Drivers/Receivers_______________________________________________________________________________________5V CC ...........................................................................-0.3V to +6V V+................................................................(V CC - 0.3V) to +14V V-............................................................................+0.3V to -14V Input VoltagesT IN ............................................................-0.3V to (V CC + 0.3V)R IN ......................................................................................±30V Output VoltagesT OUT ...................................................(V+ + 0.3V) to (V- - 0.3V)R OUT .........................................................-0.3V to (V CC + 0.3V)Short-Circuit Duration, T OUT ......................................Continuous Continuous Power Dissipation (T A = +70°C)14-Pin Plastic DIP (derate 10.00mW/°C above +70°C)....800mW 16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)....842mW 20-Pin Plastic DIP (derate 11.11mW/°C above +70°C)....889mW 24-Pin Narrow Plastic DIP(derate 13.33mW/°C above +70°C)..........1.07W24-Pin Plastic DIP (derate 9.09mW/°C above +70°C)......500mW 16-Pin Wide SO (derate 9.52mW/°C above +70°C).........762mW20-Pin Wide SO (derate 10.00mW/°C above +70°C).......800mW 24-Pin Wide SO (derate 11.76mW/°C above +70°C).......941mW 28-Pin Wide SO (derate 12.50mW/°C above +70°C) .............1W 44-Pin Plastic FP (derate 11.11mW/°C above +70°C).....889mW 14-Pin CERDIP (derate 9.09mW/°C above +70°C)..........727mW 16-Pin CERDIP (derate 10.00mW/°C above +70°C)........800mW 20-Pin CERDIP (derate 11.11mW/°C above +70°C)........889mW 24-Pin Narrow CERDIP(derate 12.50mW/°C above +70°C)..............1W24-Pin Sidebraze (derate 20.0mW/°C above +70°C)..........1.6W 28-Pin SSOP (derate 9.52mW/°C above +70°C).............762mW Operating Temperature RangesMAX2 _ _ C _ _......................................................0°C to +70°C MAX2 _ _ E _ _...................................................-40°C to +85°C MAX2 _ _ M _ _......................................................-55°C to +125°C Storage Temperature Range.............................-65°C to +160°C Lead Temperature (soldering, 10s) (Note 4)...................+300°CABSOLUTE MAXIMUM RATINGS—MAX223/MAX230–MAX241ELECTRICAL CHARACTERISTICS—MAX223/MAX230–MAX241(MAX223/230/232/234/236/237/238/240/241, V CC = +5V ±10; MAX233/MAX235, V CC = 5V ±5%‚ C1–C4 = 1.0µF; MAX231/MAX239,V CC = 5V ±10%; V+ = 7.5V to 13.2V; T A = T MIN to T MAX ; unless otherwise noted.)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Note 4:Maximum reflow temperature for the MAX233/MAX235 is +225°C.M A X 220–M A X 249+5V-Powered, Multichannel RS-232Drivers/Receivers 6_______________________________________________________________________________________ELECTRICAL CHARACTERISTICS—MAX223/MAX230–MAX241 (continued)(MAX223/230/232/234/236/237/238/240/241, V CC = +5V ±10; MAX233/MAX235, V CC = 5V ±5%‚ C1–C4 = 1.0µF; MAX231/MAX239,V CC = 5V ±10%; V+ = 7.5V to 13.2V; T A = T MIN to T MAX ; unless otherwise noted.)MAX220–MAX249+5V-Powered, Multichannel RS-232Drivers/Receivers_______________________________________________________________________________________78.56.54.55.5TRANSMITTER OUTPUT VOLTAGE (V OH ) vs. V CC7.08.0V CC (V)V O H (V )5.07.57.46.02500TRANSMITTER OUTPUT VOLTAGE (V OH )vs. LOAD CAPACITANCE AT DIFFERENT DATA RATES6.46.27.27.0LOAD CAPACITANCE (pF)V O H (V )1500100050020006.86.612.04.02500TRANSMITTER SLEW RATE vs. LOAD CAPACITANCE6.05.011.09.010.0LOAD CAPACITANCE (pF)S L E W R A T E (V /μs )1500100050020008.07.0-6.0-9.04.55.5TRANSMITTER OUTPUT VOLTAGE (V OL ) vs. V CC-8.0-8.5-6.5-7.0V CC (V)V O L (V )5.0-7.5-6.0-7.62500TRANSMITTER OUTPUT VOLTAGE (V OL )vs. LOAD CAPACITANCE AT DIFFERENT DATA RATES-7.0-7.2-7.4-6.2-6.4LOAD CAPACITANCE (pF)V O L (V )150010005002000-6.6-6.810-105101520253035404550TRANSMITTER OUTPUT VOLTAGE (V+, V-)vs. LOAD CURRENT-2-6-4-886CURRENT (mA)V +, V - (V )420__________________________________________Typical Operating CharacteristicsMAX223/MAX230–MAX241*SHUTDOWN POLARITY IS REVERSED FOR NON MAX241 PARTSV+, V- WHEN EXITING SHUTDOWN(1μF CAPACITORS)MAX220-13SHDN*V-O V+500ms/divM A X 220–M A X 249+5V-Powered, Multichannel RS-232Drivers/Receivers 8_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGS—MAX225/MAX244–MAX249ELECTRICAL CHARACTERISTICS—MAX225/MAX244–MAX249(MAX225, V CC = 5.0V ±5%; MAX244–MAX249, V CC = +5.0V ±10%, external capacitors C1–C4 = 1µF; T A = T MIN to T MAX ; unless oth-erwise noted.)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Supply Voltage (V CC )...............................................-0.3V to +6V Input VoltagesT IN ‚ ENA , ENB , ENR , ENT , ENRA ,ENRB , ENTA , ENTB ..................................-0.3V to (V CC + 0.3V)R IN .....................................................................................±25V T OUT (Note 5).....................................................................±15V R OUT ........................................................-0.3V to (V CC + 0.3V)Short Circuit (one output at a time)T OUT to GND............................................................Continuous R OUT to GND............................................................ContinuousContinuous Power Dissipation (T A = +70°C)28-Pin Wide SO (derate 12.50mW/°C above +70°C).............1W 40-Pin Plastic DIP (derate 11.11mW/°C above +70°C)...611mW 44-Pin PLCC (derate 13.33mW/°C above +70°C)...........1.07W Operating Temperature RangesMAX225C_ _, MAX24_C_ _ ..................................0°C to +70°C MAX225E_ _, MAX24_E_ _ ...............................-40°C to +85°C Storage Temperature Range.............................-65°C to +160°C Lead Temperature (soldering,10s) (Note 6)....................+300°CNote 5:Input voltage measured with transmitter output in a high-impedance state, shutdown, or V CC = 0V.Note 6:Maximum reflow temperature for the MAX225/MAX245/MAX246/MAX247 is +225°C.MAX220–MAX249+5V-Powered, Multichannel RS-232Drivers/Receivers_______________________________________________________________________________________9Note 7:The 300Ωminimum specification complies with EIA/TIA-232E, but the actual resistance when in shutdown mode or V CC =0V is 10M Ωas is implied by the leakage specification.ELECTRICAL CHARACTERISTICS—MAX225/MAX244–MAX249 (continued)(MAX225, V CC = 5.0V ±5%; MAX244–MAX249, V CC = +5.0V ±10%, external capacitors C1–C4 = 1µF; T A = T MIN to T MAX ; unless oth-erwise noted.)M A X 220–M A X 249+5V-Powered, Multichannel RS-232Drivers/Receivers 10________________________________________________________________________________________________________________________________Typical Operating CharacteristicsMAX225/MAX244–MAX24918212345TRANSMITTER SLEW RATE vs. LOAD CAPACITANCE86416LOAD CAPACITANCE (nF)T R A N S M I T T E R S L E W R A T E (V /μs )14121010-105101520253035OUTPUT VOLTAGEvs. LOAD CURRENT FOR V+ AND V--2-4-6-88LOAD CURRENT (mA)O U T P U T V O L T A G E (V )64209.05.012345TRANSMITTER OUTPUT VOLTAGE (V+, V-)vs. LOAD CAPACITANCE AT DIFFERENT DATA RATES6.05.58.5LOAD CAPACITANCE (nF)V +, V (V )8.07.57.06.5MAX220–MAX249Drivers/ReceiversFigure 1. Transmitter Propagation-Delay Timing Figure 2. Receiver Propagation-Delay TimingFigure 3. Receiver-Output Enable and Disable Timing Figure 4. Transmitter-Output Disable TimingM A X 220–M A X 249Drivers/Receivers ENT ENR OPERATION STATUS TRANSMITTERSRECEIVERS00Normal Operation All Active All Active 01Normal Operation All Active All 3-State10Shutdown All 3-State All Low-Power Receive Mode 11ShutdownAll 3-StateAll 3-StateTable 1a. MAX245 Control Pin ConfigurationsENT ENR OPERATION STATUS TRANSMITTERS RECEIVERSTA1–TA4TB1–TB4RA1–RA5RB1–RB500Normal Operation All Active All Active All Active All Active 01Normal Operation All Active All Active RA1–RA4 3-State,RA5 Active RB1–RB4 3-State,RB5 Active 1ShutdownAll 3-StateAll 3-StateAll Low-Power Receive Mode All Low-Power Receive Mode 11Shutdown All 3-State All 3-StateRA1–RA4 3-State,RA5 Low-Power Receive ModeRB1–RB4 3-State,RB5 Low-Power Receive ModeTable 1b. MAX245 Control Pin ConfigurationsTable 1c. MAX246 Control Pin ConfigurationsENA ENB OPERATION STATUS TRANSMITTERS RECEIVERSTA1–TA4TB1–TB4RA1–RA5RB1–RB500Normal Operation All Active All Active All Active All Active 01Normal Operation All Active All 3-State All Active RB1–RB4 3-State,RB5 Active 1ShutdownAll 3-StateAll ActiveRA1–RA4 3-State,RA5 Active All Active 11Shutdown All 3-State All 3-StateRA1–RA4 3-State,RA5 Low-Power Receive ModeRB1–RB4 3-State,RA5 Low-Power Receive ModeMAX220–MAX249Drivers/ReceiversM A X 220–M A X 249_______________Detailed DescriptionThe MAX220–MAX249 contain four sections: dual charge-pump DC-DC voltage converters, RS-232 dri-vers, RS-232 receivers, and receiver and transmitter enable control inputs.Dual Charge-Pump Voltage ConverterThe MAX220–MAX249 have two internal charge-pumps that convert +5V to ±10V (unloaded) for RS-232 driver operation. The first converter uses capacitor C1 to dou-ble the +5V input to +10V on C3 at the V+ output. The second converter uses capacitor C2 to invert +10V to -10V on C4 at the V- output.A small amount of power may be drawn from the +10V (V+) and -10V (V-) outputs to power external circuitry (see the Typical Operating Characteristics section),except on the MAX225 and MAX245–MAX247, where these pins are not available. V+ and V- are not regulated,so the output voltage drops with increasing load current.Do not load V+ and V- to a point that violates the mini-mum ±5V EIA/TIA-232E driver output voltage when sourcing current from V+ and V- to external circuitry. When using the shutdown feature in the MAX222,MAX225, MAX230, MAX235, MAX236, MAX240,MAX241, and MAX245–MAX249, avoid using V+ and V-to power external circuitry. When these parts are shut down, V- falls to 0V, and V+ falls to +5V. For applica-tions where a +10V external supply is applied to the V+pin (instead of using the internal charge pump to gen-erate +10V), the C1 capacitor must not be installed and the SHDN pin must be tied to V CC . This is because V+is internally connected to V CC in shutdown mode.RS-232 DriversThe typical driver output voltage swing is ±8V when loaded with a nominal 5k ΩRS-232 receiver and V CC =+5V. Output swing is guaranteed to meet the EIA/TIA-232E and V.28 specification, which calls for ±5V mini-mum driver output levels under worst-case conditions.These include a minimum 3k Ωload, V CC = +4.5V, and maximum operating temperature. Unloaded driver out-put voltage ranges from (V+ -1.3V) to (V- +0.5V).Input thresholds are both TTL and CMOS compatible.The inputs of unused drivers can be left unconnected since 400k Ωinput pullup resistors to V CC are built in (except for the MAX220). The pullup resistors force the outputs of unused drivers low because all drivers invert.The internal input pullup resistors typically source 12µA,except in shutdown mode where the pullups are dis-abled. Driver outputs turn off and enter a high-imped-ance state—where leakage current is typically microamperes (maximum 25µA)—when in shutdownmode, in three-state mode, or when device power is removed. Outputs can be driven to ±15V. The power-supply current typically drops to 8µA in shutdown mode.The MAX220 does not have pullup resistors to force the outputs of the unused drivers low. Connect unused inputs to GND or V CC .The MAX239 has a receiver three-state control line, and the MAX223, MAX225, MAX235, MAX236, MAX240,and MAX241 have both a receiver three-state control line and a low-power shutdown control. Table 2 shows the effects of the shutdown control and receiver three-state control on the receiver outputs.The receiver TTL/CMOS outputs are in a high-imped-ance, three-state mode whenever the three-state enable line is high (for the MAX225/MAX235/MAX236/MAX239–MAX241), and are also high-impedance whenever the shutdown control line is high.When in low-power shutdown mode, the driver outputs are turned off and their leakage current is less than 1µA with the driver output pulled to ground. The driver output leakage remains less than 1µA, even if the transmitter output is backdriven between 0V and (V CC + 6V). Below -0.5V, the transmitter is diode clamped to ground with 1k Ωseries impedance. The transmitter is also zener clamped to approximately V CC + 6V, with a series impedance of 1k Ω.The driver output slew rate is limited to less than 30V/µs as required by the EIA/TIA-232E and V.28 specifica-tions. Typical slew rates are 24V/µs unloaded and 10V/µs loaded with 3Ωand 2500pF.RS-232 ReceiversEIA/TIA-232E and V.28 specifications define a voltage level greater than 3V as a logic 0, so all receivers invert.Input thresholds are set at 0.8V and 2.4V, so receivers respond to TTL level inputs as well as EIA/TIA-232E and V.28 levels.The receiver inputs withstand an input overvoltage up to ±25V and provide input terminating resistors withDrivers/ReceiversTable 2. Three-State Control of ReceiversMAX220–MAX249Drivers/Receiversnominal 5k Ωvalues. The receivers implement Type 1interpretation of the fault conditions of V.28 and EIA/TIA-232E.The receiver input hysteresis is typically 0.5V with a guaranteed minimum of 0.2V. This produces clear out-put transitions with slow-moving input signals, even with moderate amounts of noise and ringing. The receiver propagation delay is typically 600ns and is independent of input swing direction.Low-Power Receive ModeThe low-power receive mode feature of the MAX223,MAX242, and MAX245–MAX249 puts the IC into shut-down mode but still allows it to receive information. This is important for applications where systems are periodi-cally awakened to look for activity. Using low-power receive mode, the system can still receive a signal that will activate it on command and prepare it for communi-cation at faster data rates. This operation conserves system power.Negative Threshold—MAX243The MAX243 is pin compatible with the MAX232A, differ-ing only in that RS-232 cable fault protection is removed on one of the two receiver inputs. This means that control lines such as CTS and RTS can either be driven or left floating without interrupting communication. Different cables are not needed to interface with different pieces of equipment.The input threshold of the receiver without cable fault protection is -0.8V rather than +1.4V. Its output goes positive only if the input is connected to a control line that is actively driven negative. If not driven, it defaults to the 0 or “OK to send” state. Normally‚ the MAX243’s other receiver (+1.4V threshold) is used for the data line (TD or RD)‚ while the negative threshold receiver is con-nected to the control line (DTR‚ DTS‚ CTS‚ RTS, etc.). Other members of the RS-232 family implement the optional cable fault protection as specified by EIA/TIA-232E specifications. This means a receiver output goes high whenever its input is driven negative‚ left floating‚or shorted to ground. The high output tells the serial communications IC to stop sending data. To avoid this‚the control lines must either be driven or connected with jumpers to an appropriate positive voltage level.Shutdown—MAX222–MAX242On the MAX222‚ MAX235‚ MAX236‚ MAX240‚ and MAX241‚ all receivers are disabled during shutdown.On the MAX223 and MAX242‚ two receivers continue to operate in a reduced power mode when the chip is in shutdown. Under these conditions‚ the propagation delay increases to about 2.5µs for a high-to-low input transition. When in shutdown, the receiver acts as a CMOS inverter with no hysteresis. The MAX223 and MAX242 also have a receiver output enable input (EN for the MAX242 and EN for the MAX223) that allows receiver output control independent of SHDN (SHDN for MAX241). With all other devices‚ SHDN (SH DN for MAX241) also disables the receiver outputs.The MAX225 provides five transmitters and five receivers‚ while the MAX245 provides ten receivers and eight transmitters. Both devices have separate receiver and transmitter-enable controls. The charge pumps turn off and the devices shut down when a logic high is applied to the ENT input. In this state, the supply cur-rent drops to less than 25µA and the receivers continue to operate in a low-power receive mode. Driver outputs enter a high-impedance state (three-state mode). On the MAX225‚ all five receivers are controlled by the ENR input. On the MAX245‚ eight of the receiver out-puts are controlled by the ENR input‚ while the remain-ing two receivers (RA5 and RB5) are always active.RA1–RA4 and RB1–RB4 are put in a three-state mode when ENR is a logic high.Receiver and Transmitter EnableControl InputsThe MAX225 and MAX245–MAX249 feature transmitter and receiver enable controls.The receivers have three modes of operation: full-speed receive (normal active)‚ three-state (disabled)‚ and low-power receive (enabled receivers continue to function at lower data rates). The receiver enable inputs control the full-speed receive and three-state modes. The transmitters have two modes of operation: full-speed transmit (normal active) and three-state (disabled). The transmitter enable inputs also control the shutdown mode. The device enters shutdown mode when all transmitters are disabled. Enabled receivers function in the low-power receive mode when in shutdown.M A X 220–M A X 249Tables 1a–1d define the control states. The MAX244has no control pins and is not included in these tables. The MAX246 has ten receivers and eight drivers with two control pins, each controlling one side of the device. A logic high at the A-side control input (ENA )causes the four A-side receivers and drivers to go into a three-state mode. Similarly, the B-side control input (ENB ) causes the four B-side drivers and receivers to go into a three-state mode. As in the MAX245, one A-side and one B-side receiver (RA5 and RB5) remain active at all times. The entire device is put into shut-down mode when both the A and B sides are disabled (ENA = ENB = +5V).The MAX247 provides nine receivers and eight drivers with four control pins. The ENRA and ENRB receiver enable inputs each control four receiver outputs. The ENTA and ENTB transmitter enable inputs each control four drivers. The ninth receiver (RB5) is always active.The device enters shutdown mode with a logic high on both ENTA and ENTB .The MAX248 provides eight receivers and eight drivers with four control pins. The ENRA and ENRB receiver enable inputs each control four receiver outputs. The ENTA and ENTB transmitter enable inputs control four drivers each. This part does not have an always-active receiver. The device enters shutdown mode and trans-mitters go into a three-state mode with a logic high on both ENTA and ENTB .The MAX249 provides ten receivers and six drivers with four control pins. The ENRA and ENRB receiver enable inputs each control five receiver outputs. The ENTA and ENTB transmitter enable inputs control three dri-vers each. There is no always-active receiver. The device enters shutdown mode and transmitters go into a three-state mode with a logic high on both ENTA and ENTB . In shutdown mode, active receivers operate in a low-power receive mode at data rates up to 20kb/s.__________Applications InformationFigures 5 through 25 show pin configurations and typi-cal operating circuits. In applications that are sensitive to power-supply noise, V CC should be decoupled to ground with a capacitor of the same value as C1 and C2 connected as close as possible to the device.Drivers/Receivers。

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