TOP开关芯片资料
TOP系列应用指南
ENTER APPLICATION VARIABLES
VACMIN
VACMAX
fL
VO PO_AVG PO_PEAK Heatsink Type Enclosure n Z VB tC CIN
85 265
50 5.00 35.00
External Adapter
0.80 0.50
12 3.00 68.0
的EcoSmart®技术令使用TOPSwitch-JX产品系列设计的电源， 其空载功耗小于100 mW，并在整个输入电压及负载范围内保持恒 定的效率。TOPSwitch-JX系列解决方案能够轻松满足欧盟行为准 则(CoC)、欧盟委员会用能产品生态设计指令(EC EuP)及能源之星 等能效标准。
基本电路结构
图2显示了在两个不同的峰值负载条件下如何计算所要求的平均 输出功率。
从表2当中确定输入电压范围。 额定输入电压(VAC)
VACMIN
VACMAX
100/115
85
132
230
195
265
通用电压范围
85
265
其
中
P
X
表
示
不
同
的
输
出
功
率
，
∆
t
表
X
示
每
个
峰
值
功
率
的
持
续
时
间，T为脉冲负载循环一次所需的时间。
特定应用的个别要求，如恒流、恒定输出功率等不在本设计指南 的讨论范围。但是，可以在本文所示的基本转换器电路当中增加 额外的电路来实现这些特别的要求。有关其它电路功能、设计范 例的更多信息及其它信息，请访问Power Integrations的网站或联 系您的PI销售代表。
开关电源top224芯片
绪论开关电源（Switched Mode Power Supply，SMPS）是一种由占空比控制的开关电路构成的电能变换装置，用于交流—直流或直流—直流电能的变换。
其功率从零点几瓦到数十千瓦，被广泛用于生活、生产、科研、军事等各个领域。
比如：小到彩色电视机、DVD播放机等家用电器、大到飞机、卫星、导弹、舰船中，都大量采用了开关电源。
开关电源的核心为电力电子开关电路，根据负载对电源提出的输出稳压或稳流特性的要求，利用反馈控制电路，采用占空比控制方法，对开关电路进行控制。
脉宽调制（PWM）技术的发展，导致了PWM开关电源问世（PWM开关电源的特点是用20KHz的载波进行脉冲宽度调制，电源的效率可达65%～70%），大幅度节约了能源，引起了人们的广泛关注，在电源技术发展史上被誉为20KHz革命。
高频化使开关电源装置空前的小型化，并使其进入更广泛的领域，特别是推动了高新技术产品的小型化、轻便化，在节约资源及保护环境方面具有深远的意义。
随着电子技术的高速发展，电子设备的应用领域越来越广，与人们的工作、生活的关系日益密切。
但是，任何电子设备都离不开可靠的电源，它们对电源的要求也越来越高。
并且，随着集成芯片尺寸的不断减小，处理速度越来越高，需要更加小型化、轻量化的电源（磁性元件和电容的体积、重量应随之减小）；未来的绿色电源要求开关电源的效率更高，性能更好，可靠性更高等。
这一切将促进开关电源的不断发展和进步。
开关电源体积小、效率高，被誉为高效节能电源，现已成为稳压电源的主导产品。
当今开关电源正向着集成化、智能化的方向发展。
高度集成、功能强大的开关型稳压电源代表着开关电源发展的主流方向。
本论文主要围绕当前流行的集成开关电源芯片进行小功率开关型稳压电源特性的研究。
本文采用TOP224Y研制了一款单片开关电源，论文给出了外围电路各部分的详细设计方法，并进行了参数计算，通过实测结果分析，验证了理论的可行性。
具有较强的适用性。
TOP414中文资料
TPO414中文资料1：三端DC-DC脉宽调制开关。
2：产品亮点。
分离转换开关的低成本替代品。
只有较少的15个元件，降低成本，提高可靠性。
允许12毫米以下更小更轻的所有表面装载元件解决方案。
3：在反击式拓扑中有80%的能效。
内置的启动和电流限制，减少DC电流损耗。
低电容的MOSFET（金属氧化物半导体场效应晶体管）CMOS（互补金属氧化物半导体）控制器/门驱动器的消耗只有7Mw.70%的最大占空比最大限度的降低了传导损耗。
4：简化设计，缩短上市时间集成的脉宽调制控制器和大功率的MOSFET（金属氧化物半导体场效应晶体管）只需要一个补偿电容。
旁路和启动/自动重启的功能。
5：系统电平错误保护特征自动重启和逐周期电流限制（逐周期电流感测）即时性电流限制功能。
处理初级和次级的错误。
在线的片锁热关断保护整个系统，预防过载。
6：高度灵活，多功能实现降压，升压，反激式和正激式拓扑。
轻松接口，同时包含OPTO和初级反馈。
支持连续和不连续的运作模式。
指定用于DC16V以下输入。
7：说明TOPS开关系列，实现只有3个终端，为所有DC-DC所必须的功能：高电压N沟道功率MOSFET（金属氧化物半导体场效应晶体管），包含受控的启动门驱动，电压模式的脉宽调节控制器有内部集成的120KHZ的震荡器。
高电压启动偏置电路，能隙带派生参考，并联分流稳压器，误差放大器电路是为环路补偿和错误保护的，相比分离的MOSFET 和控制器或字激的开关转换器解决方案，TOPS开关集成电路能降低总成本，元件的数量，尺寸，和重量，同时提高效率和系统可靠性，这个器件非常适合电信，电报，和其他DC-DC的高达21W的输出功率。
在内部，SMD-8的引线框架，使用6个引脚将热量从芯片传递到电路板上，减少了散热片的成本。
8：典型应用9：输出能力：10：引脚功能描述。
漏极引脚：输出MOSFET的漏极连接，在启动运行时候，通过内部开关式的高压电流源。
提供内部的偏置电流。
TOP224
Figure 1. Typical Flyback Application.easier. The standard 8L PDIP package option reduces cost in lower power, high efficiency applications. The internal lead frame of this package uses six of its pins to transfer heat from the chip directly to the board, eliminating the cost of a heat sink.TOPSwitch incorporates all functions necessary for a switched mode control system into a three terminal monolithic IC: power MOSFET, PWM controller, high voltage start up circuit, loop compensation and fault protection circuitry.Product Highlights•Lowest cost, lowest component count switcher solution •Cost competitive with linears above 5W•Very low AC/DC losses – up to 90% efficiency •Built-in Auto-restart and Current limiting•Latching Thermal shutdown for system level protection •Implements Flyback, Forward, Boost or Buck topology •Works with primary or opto feedback•Stable in discontinuous or continuous conduction mode •Source connected tab for low EMI•Circuit simplicity and Design Tools reduce time to marketDescriptionThe second generation TOPSwitch-II family is more cost effective and provides several enhancements over the first generation TOPSwitch family. The TOPSwitch-II family extends the power range from 100W to 150W for 100/115/230 VAC input and from 50W to 90W for 85-265 VAC universal input.This brings TOPSwitch technology advantages to many new applications, i.e. TV, Monitor, Audio amplifiers, etc. Many significant circuit enhancements that reduce the sensitivity to board layout and line transients now make the design evenNotes: 1. Package outline: TO-220/3 2. Package Outline: DIP-8 or SMD-8 3. 100/115 VAC with doubler input 4. Assumes appropriateheat sinking to keep the maximum TOPSwitch junction temperature below 100 °C. 5. Soldered to 1 sq. in.( 6.45 cm 2), 2 oz. copper clad (610 gm/m 2) 6. P MAX is the maximum practical continuous power output level for conditions shown. The continuous power capability in a given application depends on thermal environment, transformer design, efficiency required, minimum specified input voltage, input storage capacitance, etc. 7. Refer to key application considerations section when using TOPSwitch-II in an existing TOPSwitch design.July 2001Figure 2. Functional Block Diagram.Pin Functional DescriptionDRAIN Pin:Output MOSFET drain connection. Provides internal biascurrent during start-up operation via an internal switched high-voltage current source. Internal current sense point.CONTROL Pin:Error amplifier and feedback current input pin for duty cyclecontrol. Internal shunt regulator connection to provide internalbias current during normal operation. It is also used as theconnection point for the supply bypass and auto-restart/compensation capacitor.SOURCE Pin:Y package – Output MOSFET source connection for highvoltage power return. Primary side circuitcommon and reference point.P and G package – Primary side control circuit common andreference point.SOURCE (HV RTN) Pin: (P and G package only)Output MOSFET source connection for high voltage power return.Figure 3. Pin Configuration.D 7/01TOPSwitch-II Family Functional DescriptionTOPSwitch is a self biased and protected linear control current-to-duty cycle converter with an open drain output. High efficiency is achieved through the use of CMOS and integration of the maximum number of functions possible. CMOS process significantly reduces bias currents as compared to bipolar or discrete solutions. Integration eliminates external power resistors used for current sensing and/or supplying initial start-up bias current.During normal operation, the duty cycle of the internal output MOSFET decreases linearly with increasing CONTROL pin current as shown in Figure 4. To implement all the required control, bias, and protection functions, the DRAIN and CONTROL pins each perform several functions as described below. Refer to Figure 2 for a block diagram and to Figure 6 for timing and voltage waveforms of the TOPSwitch integrated circuit.Figure 4. Relationship of Duty Cycle to CONTROL Pin Current.Figure 5. Start-up Waveforms for (a) Normal Operation and (b) Auto-restart.Control Voltage SupplyCONTROL pin voltage VCis the supply or bias voltage for thecontroller and driver circuitry. An external bypass capacitorclosely connected between the CONTROL and SOURCE pinsis required to supply the gate drive current. The total amountof capacitance connected to this pin (CT) also sets the auto-restart timing as well as control loop compensation. VCisregulated in either of two modes of operation. Hystereticregulation is used for initial start-up and overload operation.Shunt regulation is used to separate the duty cycle error signalfrom the control circuit supply current. During start-up,CONTROL pin current is supplied from a high-voltage switchedcurrent source connected internally between the DRAIN andCONTROL pins. The current source provides sufficient currentto supply the control circuitry as well as charge the totalexternal capacitance (CT).The first time VCreaches the upper threshold, the high-voltagecurrent source is turned off and the PWM modulator and outputtransistor are activated, as shown in Figure 5(a). During normaloperation (when the output voltage is regulated) feedbackcontrol current supplies the VCsupply current. The shuntregulator keeps VCat typically 5.7 V by shunting CONTROLpin feedback current exceeding the required DC supply currentthrough the PWM error signal sense resistor RE. The lowdynamic impedance of this pin (ZC) sets the gain of the erroramplifier when used in a primary feedback configuration. Thedynamic impedance of the CONTROL pin together with theexternal resistance and capacitance determines the control loopcompensation of the power system.If the CONTROL pin total external capacitance (CT) shoulddischarge to the lower threshold, the output MOSFET is turnedoff and the control circuit is placed in a low-current standbymode. The high-voltage current source turns on and charges theexternal capacitance again. Charging current is shown with anegative polarity and discharging current is shown with apositive polarity in Figure 6. The hysteretic auto-restartcomparator keeps VCwithin a window of typically 4.7 to 5.7 Vby turning the high-voltage current source on and off as shownin Figure 5(b). The auto-restart circuit has a divide-by-8counter which prevents the output MOSFET from turning onagain until eight discharge-charge cycles have elapsed. Thecounter effectively limits TOPSwitch power dissipation byreducing the auto-restart duty cycle to typically 5%. Auto-restart continues to cycle until output voltage regulation isagain achieved.Bandgap ReferenceAll critical TOPSwitch internal voltages are derived from atemperature-compensated bandgap reference. This referenceis also used to generate a temperature-compensated currentsource which is trimmed to accurately set the oscillator frequencyOscillatorThe internal oscillator linearly charges and discharges theinternal capacitance between two voltage levels to create asawtooth waveform for the pulse width modulator. The oscillatorsets the pulse width modulator/current limit latch at the beginningof each cycle. The nominal frequency of 100 kHz was chosento minimize EMI and maximize efficiency in power supplyapplications. Trimming of the current reference improves thefrequency accuracy.Pulse Width ModulatorThe pulse width modulator implements a voltage-mode controlloop by driving the output MOSFET with a duty cycle inverselyproportional to the current into the CONTROL pin whichgenerates a voltage error signal across RE. The error signalacross REis filtered by an RC network with a typical cornerfrequency of 7 kHz to reduce the effect of switching noise. Thefiltered error signal is compared with the internal oscillatorsawtooth waveform to generate the duty cycle waveform. Asthe control current increases, the duty cycle decreases. A clocksignal from the oscillator sets a latch which turns on the outputMOSFET. The pulse width modulator resets the latch, turningoff the output MOSFET. The maximum duty cycle is set by thesymmetry of the internal oscillator. The modulator has aminimum ON-time to keep the current consumption of theTOPSwitch independent of the error signal. Note that a minimumcurrent must be driven into the CONTROL pin before the dutycycle begins to change.Gate DriverThe gate driver is designed to turn the output MOSFET on at acontrolled rate to minimize common-mode EMI. The gate drivecurrent is trimmed for improved accuracy.Error AmplifierThe shunt regulator can also perform the function of an erroramplifier in primary feedback applications. The shunt regulatorvoltage is accurately derived from the temperature compensatedbandgap reference. The gain of the error amplifier is set by theCONTROL pin dynamic impedance. The CONTROL pinclamps external circuit signals to the VCvoltage level. TheCONTROL pin current in excess of the supply current isseparated by the shunt regulator and flows through REas avoltage error signal.Cycle-By-Cycle Current LimitThe cycle by cycle peak drain current limit circuit uses theoutput MOSFET ON-resistance as a sense resistor. A currentlimit comparator compares the output MOSFET ON-state drain-source voltage, VDS(ON)with a threshold voltage. High draincurrent causes VDS(ON)to exceed the threshold voltage and turnsthe output MOSFET off until the start of the next clock cycle.The current limit comparator threshold voltage is temperature TOPSwitch-II Family Functional Description (cont.)D 7/01compensated to minimize variation of the effective peak current limit due to temperature related changes in output MOSFET R DS(ON).The leading edge blanking circuit inhibits the current limit comparator for a short time after the output MOSFET is turned on. The leading edge blanking time has been set so that current spikes caused by primary-side capacitances and secondary-side rectifier reverse recovery time will not cause premature termination of the switching pulse.The current limit can be lower for a short period after the leading edge blanking time as shown in Figure 12. This is due to dynamic characteristics of the MOSFET. To avoid triggering the current limit in normal operation, the drain current waveform should stay within the envelope shown.Shutdown/Auto-restartTo minimize TOPSwitch power dissipation, the shutdown/auto-restart circuit turns the power supply on and off at an auto-restart duty cycle of typically 5% if an out of regulation condition persists. Loss of regulation interrupts the external current into the CONTROL pin. V C regulation changes from shunt mode to the hysteretic auto-restart mode described above.When the fault condition is removed, the power supply outputbecomes regulated, V C regulation returns to shunt mode, and normal operation of the power supply resumes.Overtemperature ProtectionTemperature protection is provided by a precision analog circuit that turns the output MOSFET off when the junction temperature exceeds the thermal shutdown temperature (typically 135 °C). Activating the power-up reset circuit by removing and restoring input power or momentarily pulling the CONTROL pin below the power-up reset threshold resets the latch and allows TOPSwitch to resume normal power supply operation. V C is regulated in hysteretic mode and a 4.7 V to 5.7 V (typical) sawtooth waveform is present on the CONTROL pin when the power supply is latched off.High-voltage Bias Current SourceThis current source biases TOPSwitch from the DRAIN pin and charges the CONTROL pin external capacitance (C T ) during start-up or hysteretic operation. Hysteretic operation occurs during auto-restart and overtemperature latched shutdown.The current source is switched on and off with an effective duty cycle of approximately 35%. This duty cycle is determined by the ratio of CONTROL pin charge (I C ) and discharge currents (I CD1 and I CD2). This current source is turned off during normal operation when the output MOSFET is switching.Figure 6. Typical Waveforms for (1) Normal Operation, (2) Auto-restart, and (3) Power Down Reset.Figure 7. Schematic Diagram of a 4 W TOPSwitch-II Standby Power Supply using an 8 lead PDIP.Application ExamplesFollowing are just two of the many possible TOPSwitchimplementations. Refer to the Data Book and Design Guidefor additional examples.4 W Standby Supply using 8 Lead PDIPFigure 7 shows a 4 W standby supply. This supply is used inappliances where certain standby functions (e.g. real timeclock, remote control port) must be kept active even while themain power supply is turned off.The 5 V secondary is used to supply the standby function andthe 12 V non-isolated output is used to supply power for thePWM controller of the main power supply and other primaryside functions.For this application the input rectifiers and input filter are sizedfor the main supply and are not shown. The input DC rail mayvary from 100 V to 380 V DC which corresponds to the fulluniversal AC input range. The TOP221 is packaged in an 8 pinpower DIP package.The output voltage (5 V) is directly sensed by the Zener diode(VR1) and the optocoupler (U2). The output voltage is determinedby the sum of the Zener voltage and the voltage drop across theLED of the optocoupler (the voltage drop across R1 is negligible).The output transistor of the optocoupler drives the CONTROLpin of the TOP221. C5 bypasses the CONTROL pin and providescontrol loop compensation and sets the auto-restart frequency.The transformer’s leakage inductance voltage spikes are snubbedby R3 and C1 through diode D1. The bias winding is rectifiedand filtered by D3 and C4 providing a non-isolated 12 V outputwhich is also used to bias the collector of the optocoupler’soutput transistor. The isolated 5 V output winding is rectified byD2 and filtered by C2, L1 and C3.D 7/0120 W Universal Supply using 8 Lead PDIPFigure 8 shows a 12 V, 20 W secondary regulated flyback power supply using the TOP224P in an eight lead PDIP package and operating from universal 85 to 265 VAC input voltage. This example demonstrates the advantage of the higher power 8 pin leadframe used with the TOPSwitch-II family. This low cost package transfers heat directly to the board through six source pins, eliminating the heatsink and the associated cost. Efficiency is typically 80% at low line input. Output voltage is directly sensed by optocoupler U2 and Zener diode VR2. The output voltage is determined by the Zener diode (VR2) voltage and the voltage drops across the optocoupler (U2) LED and resistor R1.Other output voltages are possible by adjusting the transformer turns ratio and value of Zener diode VR2.AC power is rectified and filtered by BR1 and C1 to create the high voltage DC bus applied to the primary winding of T1. The other side of the transformer primary is driven by the integrated TOPSwitch-II high-voltage MOSFET. D1 and VR1 clampleading-edge voltage spikes caused by transformer leakage inductance. The power secondary winding is rectified and filtered by D2, C2, L1, and C3 to create the 12 V output voltage.R2 and VR2 provide a slight pre-load on the 12 V output to improve load regulation at light loads. The bias winding is rectified and filtered by D3 and C4 to create a TOPSwitch bias voltage. L2 and Y1-safety capacitor C7 attenuate common mode emission currents caused by high voltage switching waveforms on the DRAIN side of the primary winding and the primary to secondary capacitance. Leakage inductance of L2with C1 and C6 attenuates differential-mode emission currents caused by the fundamental and harmonics of the trapezoidal or triangular primary current waveform. C5 filters internal MOSFET gate drive charge current spikes on the CONTROL pin, determines the auto-restart frequency, and together with R1 and R3, compensates the control loop.Figure 8. Schematic Diagram of a 20 W Universal Input TOPSwitch-II Power Supply using an 8 lead PDIP.Key Application ConsiderationsGeneral Guidelines• Keep the SOURCE pin length very short. Use a Kelvinconnection to the SOURCE pin for the CONTROL pinbypass capacitor. Use single point grounding techniques atthe SOURCE pin as shown in Figure 9.• Minimize peak voltage and ringing on the DRAIN voltageat turn-off. Use a Zener or TVS Zener diode to clamp thedrain voltage below the breakdown voltage rating ofTOPSwitch under all conditions, including start-up andoverload. The maximum recommended clamp Zenervoltage for the TOP2XX series is 200 V and thecorresponding maximum reflected output voltage on theprimary is 135 V. Please see Step 4: AN-16 in the 1996-97Data Book and Design Guide or on our Web site.• The transformer should be designed such that the rate ofchange of drain current due to transformer saturation iswithin the absolute maximum specification (∆IDin 100 nsbefore turn off as shown in Figure 13). As a guideline, formost common transformer cores, this can be achieved bymaintaining the Peak Flux Density (at maximum ILIMITcurrent) below 4200 Gauss (420 mT). The transformerspreadsheets Rev. 2.1 (or later) for continuous and Rev.1.0(or later) for discontinuous conduction mode provide thenecessary information.• Do not plug TOPSwitch into a “hot” IC socket during test.External CONTROL pin capacitance may be charged toexcessive voltage and cause TOPSwitch damage.• While performing TOPSwitch device tests, do not exceedmaximum CONTROL pin voltage of 9 V or maximumCONTROL pin current of 100 mA.• Under some conditions, externally provided bias or supplycurrent driven into the CONTROL pin can hold theTOPSwitch in one of the 8 auto-restart cycles indefinitelyand prevent starting. To avoid this problem when doingbench evaluations, it is recommended that the VCpowersupply be turned on before the DRAIN voltage is applied.TOPSwitch can also be reset by shorting the CONTROLpin to the SOURCE pin momentarily.• CONTROL pin currents during auto-restart operation aremuch lower at low input voltages (< 36 V) which increasesthe auto-restart cycle time (see the ICvs. DRAIN VoltageCharacteristic curve).• Short interruptions of AC power may cause TOPSwitch toenter the 8-count auto-restart cycle before starting again.This is because the input energy storage capacitors are notcompletely discharged and the CONTROL pin capacitancehas not discharged below the internal power-up resetvoltage.• In some cases, minimum loading may be necessary to keepa lightly loaded or unloaded output voltage within thedesired range due to the minimum ON-time.Replacing TOPSwitch with TOPSwitch-IIThere is no external latching shutdown function inTOPSwitch-II. Otherwise, the functionality of theTOPSwitch-II devices is same as that of the TOPSwitch family.However, before considering TOPSwitch-II as a 'drop in'replacement in an existing TOPSwitch design, the designshould be verified as described below.The new TOPSwitch-II family offers more power capabilitythan the original TOPSwitch family for the same MOSFETRDS(ON). Therefore, the original TOPSwitch design must bereviewed to make sure that the selected TOPSwitch-IIreplacement device and other primary components are not overstressed under abnormal conditions.The following verification steps are recommended:• Check the transformer design to make sure that it meets the∆IDspecification as outlined in the General Guidelinessection above.• Thermal: Higher power capability of the TOPSwitch-IIwould in many instances allow use of a smaller MOSFETdevice (higher RDS(ON)) for reduced cost. This may affectTOPSwitch power dissipation and power supply efficiency.Therefore thermal performance of the power supply mustbe verified with the selected TOPSwitch-II device.• Clamp Voltage: Reflected and Clamp voltages should beverified not to exceed recommended maximums for theTOP2XX Series: 135 V Reflected/200 V Clamp. Pleasesee Step 4: AN-16 in the Data Book and Design Guide andreadme.txt file attached to the transformer designspreadsheets.• Agency Approval: Migrating to TOPSwitch-II may requireagency re-approval.D 7/01Figure 9. Recommended TOPSwitch Layout.Design ToolsThe following tools available from Power Integrations greatly simplify TOPSwitch based power supply design.• Data Book and Design Guide includes extensive application information• Excel Spreadsheets for Transformer Design - Use of this tool is strongly recommended for all TOPSwitch designs.• Reference design boards – Production viable designs that are assembled and tested.All data sheets, application literature and up-to-date versions of the Transformer Design Spreadsheets can be downloaded from our Web site at . A diskette of the Transformer Design Spreadsheets may also be obtained by sending in the completed form provided at the end of this data sheet.D 7/01D 7/01NOTES:A.For specifications with negative values, a negative temperature coefficient corresponds to an increase in magnitude with increasing temperature, and a positive temperature coefficient corresponds to a decrease in magnitude with increasing temperature.B.The breakdown voltage and leakage current measurements can be accomplished as shown in Figure 15 by using the following sequence:i. The curve tracer should initially be set at 0 V. The base output should be adjusted through a voltage sequence of 0 V, 6.5 V, 4.3 V, and 6.5 V, as shown. The base current from the curve tracer should not exceed 100 mA. This CONTROL pin sequence interrupts the Auto-restart sequence and locks the TOPSwitch internal MOSFET in the OFF State.ii. The breakdown and the leakage measurements can now be taken with the curve tracer. The maximum voltage from the curve tracer must be limited to 700 V under all conditions.C.It is possible to start up and operate TOPSwitch at DRAIN voltages well below 36 V. However, the CONTROL pin charging current is reduced, which affects start-up time, auto-restart frequency, and auto-restart duty cycle. Refer to the characteristic graph on CONTROL pin charge current (I C ) vs. DRAIN voltage for low voltage operation characteristics.Figure 11. TOPSwitch CONTROL Pin I-V Characteristic. Figure 10. TOPSwitch Duty Cycle Measurement.Figure 12. Self-protection Current Limit Envelope.Figure 13. Example of ∆IDon Drain Current Waveform withSaturated Transformer.012683Time (µs)DRAINCurrent(normalized)PI-222-331457120100804020600246810CONTROL Pin Voltage (V)CONTROLPinCurrent(mA)D 7/01Figure 14. TOPSwitch General Test Circuit.Figure 15. Breakdown Voltage and Leakage Current Measurement Test Circuit.The following precautions should be followed when testingTOPSwitch by itself outside of a power supply. The schematicshown in Figure 14 is suggested for laboratory testing ofTOPSwitch.When the DRAIN supply is turned on, the part will be in theAuto-restart mode. The CONTROL pin voltage will beoscillating at a low frequency from 4.7 to 5.7 V and the DRAINis turned on every eighth cycle of the CONTROL pin oscillation.If the CONTROL pin power supply is turned on while in thisTypical Performance CharacteristicsAuto-restart mode, there is only a 12.5% chance that the controlpin oscillation will be in the correct state (DRAIN active state)so that the continuous DRAIN voltage waveform may beobserved. It is recommended that the VCpower supply beturned on first and the DRAIN power supply second if continuousdrain voltage waveforms are to be observed. The 12.5% chanceof being in the correct state is due to the 8:1 counter. Temporarilyshorting the CONTROL pin to the SOURCE pin will resetTOPSwitch, which then will come up in the correct state.21.21.6020*********DRAIN Voltage (V)CONTROLPinChargingCurrent(mA)I C vs. DRAIN VOLTAGEPI-1145-131940.40.81.11.00.9-50-250255075100125150Junction Temperature (°C)BreakdownVoltage(V)(Normalizedto25°C)BREAKDOWN vs. TEMPERATUREPI-176B-513911.21.00.80.60.40.2-50-250255075100125150Junction Temperature (°C)CURRENT LIMIT vs. TEMPERATUREPI-1125-331CurrentLimit(Normalizedto25°C)1.21.00.80.60.40.2-50-250255075100125150Junction Temperature (°C)FREQUENCY vs. TEMPERATUREPI-1123A-331OutputFrequency(Normalizedto25°C)D 7/01Typical Performance Characteristics (cont.)3246810DRAIN Voltage (V)D R A I N C u r r e n t (A )OUTPUT CHARACTERISTICSP I -1940-03300112100010400200600DRAIN Voltage (V)D R A I N C a p a c i t a n c e (p F )C OSS vs. DRAIN VOLTAGE100P I -1941-033001500300400100200200400600DRAIN Voltage (V)P o w e r (m W )DRAIN CAPACITANCE POWERP I -1942-0330017/01Notes-1) Updated package references.2) Corrected Spelling.3) Corrected Storage Temperature θJCand updated nomenclature in parameter table.4) Added G package references to Self-Protection Current Limit parameter.5) Corrected font sizes in figures.Date12/977/01 RevisionCDKOREAPower IntegrationsInternational Holdings, Inc.Rm# 402, Handuk Building649-4 Yeoksam-Dong,Kangnam-Gu,Seoul, KoreaPhone:+82-2-568-7520Fax:+82-2-568-7474e-mail: koreasales@WORLD HEADQUARTERSAMERICASPower Integrations, Inc.5245 Hellyer AvenueSan Jose, CA 95138 USAMain:+1 408-414-9200Customer Service:Phone:+1 408-414-9665Fax:+1 408-414-9765e-mail: usasales@For the latest updates, visit our Web site:Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability. Power Integrations does not assume any liability arising from the use of any device or circuit described herein, nor does it convey any license under its patent rights or the rights of others.The PI Logo, TOPSwitch, TinySwitch and EcoSmart are registered trademarks of Power Integrations, Inc.©Copyright 2001, Power Integrations, Inc.JAPANPower Integrations, K.K.Keihin-Tatemono 1st Bldg.12-20 Shin-Yokohama 2-ChomeKohoku-ku, Yokohama-shiKanagawa 222-0033, JapanPhone:+81-45-471-1021Fax:+81-45-471-3717e-mail: japansales@TAIWANPower IntegrationsInternational Holdings, Inc.17F-3, No. 510Chung Hsiao E. Rd.,Sec. 5,Taipei, Taiwan 110, R.O.C.Phone:+886-2-2727-1221Fax:+886-2-2727-1223e-mail: taiwansales@EUROPE & AFRICAPower Integrations (Europe) Ltd.Centennial CourtEasthampstead RoadBracknellBerkshire, RG12 1YQUnited KingdomPhone:+44-1344-462-300Fax:+44-1344-311-732e-mail: eurosales@CHINAPower IntegrationsInternational Holdings, Inc.Rm# 1705, Bao Hua Bldg.1016 Hua Qiang Bei LuShenzhen, Guangdong 518031ChinaPhone:+86-755-367-5143Fax:+86-755-377-9610e-mail: chinasales@INDIA (Technical Support)Innovatech#1, 8th Main RoadVasanthnagarBangalore, India 560052Phone:+91-80-226-6023Fax:+91-80-228-9727e-mail: indiasales@APPLICATIONS HOTLINEWorld Wide +1-408-414-9660APPLICATIONS FAXWorld Wide +1-408-414-9760。
top242-250cn中文
1 November 2005
版本 O 11/05
TOP242-250
目录
功能结构图.................................................................................................................................................................... 3 引脚功能描述 ................................................................................................................................................................. 4 TOPSwitch-GX 产品系列功能描述................................................................................................................................ 5
TOP242 Y 或 F TOP243 P 或 G
TOP243 R TOP243 Y 或 F TOP244 P 或 G
TOP244 R TOP244 Y 或 F TOP245 P 或 G
TOP245 R TOP245 Y 或 F TOP246 P 或 G
TOP246 R TOP246 Y 或 F
TOP412-414三端DC-DC PWM开关电源
TOP412/414 三端DC/DC PWM 开关电源
Power lntegrations 公司继TOPSwitch－Ⅱ之后，于1999 年4 月又推出TOP412/414 三端DC/DCPWM 开关。
TOP412/414 采用SMD－8（G08A）封装，其中4 脚为控制脚，5 脚为MOSFET 漏极脚，1～3 脚为源极脚，6～8 脚是源
极高压回复（HVRTN）。
TOP412/414 集电压型PWM 控制器与N 沟道功
率MOSFET 于一体，集成了120kHz 振荡器、高压起动偏置电路、温度补偿、
并联调整器/误差放大器和故障保护等电路。
TOP412/414 的内部起动和电流限
制电路减少了直流损耗，CMOS 控制器/栅极驱动器仅消耗7mW 的功率，70％
的最大占空比使导通损耗最小化，低容量MOSFET 有效地降低了开关损耗，
从而使其在回扫拓扑应用中的效率在80％以上。
TOP412/414 的保护功能包括
自动再起动与电流限制和过热关闭等。
TOP412/414 可组成升压、BUCK、回扫
和正向拓扑，输入电压和输出功率如表1。
用TOP414G 设计的10WDC/DC 变换器如图1 所示。
该变换器的DC 输
入电压范围为36～72V，输出为5V/2A，工作环境温度为0～50℃,元件最大高
度是12mm。
图1 TOP414G 的典型应用电路
表1 TOP412/414 输入电压与输出功率
最低输入电压
输出功率
TOP412G
TOP414G
18V3W4W 24V5W6W 36V7W9W 48V9W12W 60V12W15W 72V15W18W。
电源管理芯片top221p参数
电源管理芯片top221p参数
电源管理芯片TOP221P是一款高性能的离线开关电源管理芯片，具有多种参数和特性，适用于各种电源管理应用。
以下是该芯片的
一些重要参数：
1. 输入电压范围，该芯片的输入电压范围为85V至265V，使
其适用于全球范围内的电源输入。
2. 输出功率，TOP221P芯片能够提供高达12W的输出功率，适
用于各种中小功率应用。
3. 工作频率，该芯片的工作频率范围广泛，从50kHz到
200kHz可调，能够在不同的应用场景下实现最佳的性能。
4. 内置保护功能，TOP221P芯片具有多种内置保护功能，包括
过载保护、过温保护和短路保护，确保电路的稳定和可靠性。
5. 封装类型，该芯片采用TO-220封装，便于安装和散热，适
用于各种工业和商业应用。
综合来看，电源管理芯片TOP221P具有宽输入电压范围、高输出功率、可调工作频率和多重保护功能等特点，适用于各种电源管理和开关电源应用。
它的性能稳定可靠，是电源管理领域的重要组成部分。
top开关电源设计及电路2
TOPSwitch-FX系列单片机开关电源的应用摘要：介绍TOPSwitch-FX系列产品在通用高效开关电源、机顶盒开关电源、PC 待机电源中的典型应用。
TOPSwitch-FX系列单片机电源集成电路，可广泛应用于各种通用及专用开关电源、待机电源、开关电源模块中。
一、能进行外部限流的12V、30W开关电源由TOP234Y构成12V、30W高效开关电源的电路如图1所示。
其交流输入电压范围是AC85～265V，满载时电源效率可达80%。
交流电压u依次经过电磁干扰（EMI）滤波器（C10，L1）、输入整流滤波器（BR，C1）获得直流高压UI。
UI经过R1和R2分压后接M端，能使极限电流随UI升高而降低。
R1可提供电压前馈信号，当UI偏高时能自动降低最大占空比，以减小输出纹波。
R2为电流极限设定电阻，所设定的Ilimit≈0.7Ilimit=0.7×1.5A=1.05A，略高于低压输入时的峰值电流Ip值。
这里将系数取0.7是考虑到TOP234Y在宽范围输入时，最大连续输出功率Pom=45W,而实际输出功率P'om=30M，即P'om/Pom=30/45=0.67≈0.7。
采用这种设计方法允许高频变压器选用尺寸较小的磁芯，通过增加初级电感量Lp来降低TOP234Y的功耗，并防止出现磁饱和现象。
此外，由于采用了降低Dmax的电压前馈技术即使输入电压UI和初级感应电压UOR较高，开关电源也能正常工作。
它允许使用成本的R，C，VD型漏极钳位电路（R3，C7，VD1），以替代价格较高的TVS（瞬态电压抑制器）、VD型钳位电路，用于吸收在TOP234Y关断时由高频变压器漏感产生的尖峰电压，对漏极起到保护作用。
次级电压经过VD2，C2，C3，L2和C4整流滤波后，获得+12V、2.5A的稳压输出。
为减小整流管的损耗，VD2采用MBR1060型10A/60V肖特基二极管。
C9和R7并联在VD2两端，能防止VD2在高频开关状态下产生自激振荡（振铃）。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
TOP开关电源芯片工作原理及应用电路
--------------------------------------------------------------------------------
TOP开关电源芯片工作原理及应用电路
1.什么叫TOP开关电源芯片
TOP开关电源的芯片组是三端离线式脉宽调制单片开关集成电路TOP(ThreeterminalofflinePWM)的简称,TOP将PWM控制器与功率开关MOSFET合二为一封装在一起，。
采用TOP开关集成电路设计开关电源，可使电路大为简化，体积进一步缩小，成本也明显降低。
2.TOP开关结构及工作原理
2.1 结构
TOP开关集各种控制功能、保护功能及耐压700V的功率开关MOSFET于一体，采用TO220或8脚DIP封装。
少数采用8脚封装的TOP开关，除D、C两引脚外，其余6脚实际连在一起，作为S端，故仍系三端器件。
三个引出端分别是漏极端D、源极端S和控制端C。
其中，D是内装MOSFET的漏极，也是内部电流的检测点，起动操作时，漏极端由一个内部电流源提供内部偏置电流。
控制端C控制输出占空比，是误差放大器和反馈电流的输入端。
在正常操作时，内部的旁路调整端提供内部偏置电流，且能在输入异常时，自动锁定保护。
源极端S是MOSFET的源极，同时是TOP开关及开关电源初级电路的公共接地点及基准点。
图1 为TOP开关电源芯片的内部结构电路图
图1TOP开关内部工作原理框图
2.2工作原理
TOP包括10部分，其中Zc为控制端的动态阻抗，RE是误差电压检测电阻。
RA与CA构
成截止频率为7kHz的低通滤波器。
主要特点是：
（1）前沿消隐设计，延迟了次级整流二级管反向恢复产生的尖峰电流冲击；
（2）自动重起动功能，以典型值为5％的自动重起动占空比接通和关断；
（3）低电磁干扰性（EMI），TOP系列器件采用了与外壳的源极相连，使金属底座及散热器的dv/dt=0，从而降低了电压型控制方式与逐周期峰值电流限制;
（4）电压型控制方式与逐周期峰值电流限制。
下面简要叙述一下：
（1）控制电压源
控制电压Uc能向并联调整器和门驱动极提供偏置电压，而控制端电流IC则能调节占空比。
控制端的总电容用Ct表示，由它决定自动重起动的定时，同时控制环路的补偿，Uc有两种工作模式，一种是滞后调节，用于起动和过载两种情况，具有延迟控制作用；另一种是并联调节，用于分离误差信号与控制电路的高压电流源。
刚起动电路时由D C极之间的高压电流源提供控制端电流Ic，以便给控制电路供电并对Ct充电。
（2）带隙基准电压源
带隙基准电压源除向内部提供各种基准电压之外，还产生一个具有温度补偿并可调整的电流源，以保证精确设定振荡器频率和门极驱动电流。
（3）振荡器
内部振荡电容是在设定的上、下阈值UH、UL之间周期性地线性充放电，以产生脉宽调制器所需要的锯齿波（SAW），与此同时还产生最大占空比信号(DMAx)和时钟信号(CLOCK)。
为减小电磁干扰，提高电源效率，振荡频率（即开关频率）设计为100kHz，脉冲波形的占空比设定为D。
（4）放大器
误差放大器的增益由控制端的动态阻抗Zc来设定。
Zc的变化范围是10Ω～20Ω，典型值为15Ω。
误差放大器将反馈电压UF与5.7V基准电压进行比较后，输出误差电流Ir，在RE 上形成误差电压UR。
（5）脉宽调制器（PWM）
脉宽调制器是一个电压反馈式控制电路，它具有两层含义。
第一、改变控制端电流IC的大小，即可调节占空比D，实现脉宽调制。
第二、误差电压UR经由RA、CA组成截止频率为7kHz的低通滤波器，滤掉开关噪声电压之后，加至PWM比较器的同相输入端，再与锯齿波电压UJ进行比较，产生脉宽调制信号UB。
（6）门驱动级和输出级
门驱动级（F）用于驱动功率开关管(MOSFET)，使之按一定速率导通，从而将共模电磁干扰减至最小。
漏源导通电阻与产品型号和芯片结温有关。
MOSFET管的漏源击穿电压U(bo)ds≥700V。
（7）过流保护电路
过流比较器的反相输入端接阈值电压ULIMIT，同相输入端接MOSFET管的漏极。
此外，芯片还具有初始输入电流限制功能。
刚通电时可将整流后的直流限制在0.6A或0.75A。
（8）过热保护电路
当芯片结温TJ>135℃时，过热保护电路就输出高电平，将触发器Ⅱ置位，Q=1，Q=0，关断输出级。
此时进入滞后调节模式，Uc端波形也变成幅度为4.7V～5.7V的锯齿波。
若要重新起动电路，需断电后再接通电源开关；或者将控制端电压降至3.3V以下，达到Uc(reset)值，再利用上电复位电路将触发器Ⅱ置零，使MOSFET恢复正常工作。
（9）关断/自起动电路
一旦调节失控，关断/自动重起动电路立即使芯片在5％占空比下工作，同时切断从外部流入
C端的电流，Uc再次进入滞后调节模式。
倘若故障己排除，Uc又回到并联调节模式，自动重新起动电源恢复正常工作。
自动重起动的频率为1.2Hz。
（10）高压电流源
在起动或滞后调节模式下，高压电流源经过电子开关S1给内部电路提供偏置，并且对Ct 进行充电。
电源正常工作时S1改接内部电源，将高压电流源关断。
当TOP开关起动操作时，在控制端环路振荡电路的控制下，漏极端有电流流入芯片，提供开环输入。
该输入通过旁路调整器、误差放大器时，由控制端进行闭环调整，改变Ir，经由PWM控制MOSFET的输出占空比，最后达到动态平衡。
3. TOP开关的典型应用
3.1 12V/30W小功率开关电源
12V/30W小功率开关电源原理图如图2所示。
该电源特性是：简单，直接可与220V交流电源连接，经桥式整流电容滤波后产生300V直流高电压起动开关电源工作。
并且重量轻、体积小，接线简单外围元件少。
图2 12V/30W小功率开关电源原理图
该电路特点是利用三极管Q1，二极管D8及电阻R5、R6组成过低压保护电路，当输入电压降低到一定程度时，Q1导通，控制端C电位降低，TOP开关关闭，开关电源没有输出。
（1）输入电路
电网交流220V输入电压经桥式整流、电容滤波后产生300V直流高压起动开关电源工作。
（2）电源变换器部分
在该电路中，T2为高频变压器，其中
N1为初级绕组（35T）
N2为反馈绕组（15T）
N3为次级隔离输出绕组（7T）
开关电源工作后，反馈绕组N2经整流、滤波、限流后送至TOP开关控制极C，以调整TOP 开关内部PWM占空比。
当因某种原因如负载变轻引起输出电压升高时，N2电压将升高，即流入TOP开关控制端C的电流增加。
在振荡电路的控制下，漏极端D有电流流入芯片，提供开环输入，该输入通过旁路调整器、误差放大器，由控制端进行闭环调整，经由PWM 控制MOSFET的输出占空比，使其占空比线性减小，从而使输出电压下降，最后达到动态平衡，保持输出稳定。
电路中并接于初级绕组N1两端的瞬态电压抑制二极管D5、电容C4及快速二极管D6组成钳位削峰电路。
钳制电感放电脉冲的最高电位，减少漏感抗引起的漏
极端电压畸变。
在实际绕制高频电源变压器时，为了减小漏感的影响，可采用初级与次级相互交叉的绕制方法。
同时，采用自我屏蔽作用较为良好的罐形磁芯，将线圈都用磁芯封在里边。
（3）反馈控制回路
电容C6决定软起动恢复时间，C6、R5、R4、C5、D7决定控制回路的零点。
R4阻值过小，限流线性差，容易导致TOP开关损坏；过大则调整线性差。
在实验中取值为10kΩ
（4）输出回路
N3、D10、C8、D11构成输出回路。
肖特基势垒整流二极管D10对高频变压器次级的高频方波电压进行整流，经低ESR值的电解电容滤波及双向瞬态电压抑制二极管D11削峰稳压后，提供给负载电路。
R7既可改善电源本身的输出阻抗，又能小幅度地调整输出电压的范围，同时又可在电源空载时为电容C8提供放电回路。
R7取值为430Ω。
3.2 TOP204组成的12.5V/25W精密开关电源
12.5V/25W精密开关电源原理图如图3所示。
由TOP204构成隔离式＋12.5V、2A（25W）开关电源电路，该电源的特性为：当交流输入电压U从85V变化到265V时，电压调整率为±0.2％；当负载电流从10％(0.2A)变化到100％(2A)时，负载调整率也达±0.2％，可与线性集成稳压电源相媲美。
该电路的主要特点是利用一片TL431(IC3)与光电耦合器(IC2)构成外部误差放大器。
它再与片内误差放大器配合使用，对控制电流进行精细调整，从而大大提高了稳压性能。
图3 12.5V/25W精密开关电源原理图
4.结语
由于TOP芯片内部完全集成了SMPS的全部功能，所以利用它设计出的开关电源周期短，成本低，对于小功率电源，简单，体积小，重量轻。
随着TOP开关系列的不断发展与改进，其在开关电源及其它应用领域中必将有着更加灿烂的前景。