L6598高功率IC

1/16L6598February 2000s HIGH VOLTAGE RAIL UP TO 600V s dV/dt IMMUNITY ±50V/ns IN FULL TEMPERATURE RANGEsDRIVER CURRENT CAPABILITY:250mA SOURCE 450mA SINKs SWITCHING TIMES 80/40ns RISE/FALL WITH 1nF LOADs CMOS SHUT DOWN INPUT s UNDER VOLTAGE LOCK OUTs SOFT START FREQUENCY SHIFTING TIMINGs SENSE OP AMP FOR CLOSED LOOP CONTROL OR PROTECTION FEATURES s HIGH ACCURACY CURRENT CONTROLLED OSCILLATORs INTEGRATED BOOTSTRAP DIODE s CLAMPING ON VssSO16,DIP16PACKAGESDESCRIPTIONThe L6598is manufactured with the BCD OFF LINEtechnology,able to ensure voltage ratings up to 600V,making it perfectly suited for AC/DC Adapters and wherever a Resonant Topology can be benefi-cial.The device is intended to drive two Power MOS,in the classical Half Bridge Topology.A dedicated Timing Section allows the designer to set Soft Start Time,Soft Start and Minimum Frequency.An Error Amplifier,together with the two Enable inputs,are made available.In addition,the integrated Bootstrap Diode and the Zener Clamping on low voltage sup-ply,reduces to a minimum the external parts needed in the applications.DIP16SO16NORDERING NUMBERS:L6598L6598DHIGH VOLTAGE RESONANT CONTROLLERBLOCK DIAGRAMGND V REFIfminRfminVCOEN1Vthe1Vthe2EN2V SV BOOT OUTC BOOTLOADH.V.LVGUVDETECTIONVsHVGBOOTSTRAP DRIVERHVG DRIVERLVG DRIVERCssV REFIfstartRfstartCfOP AMP+ -OPOUT OPIN- OPIN+DEAD TIME DRIVING LOGICCONTROL LOGICIss+- + - LEVEL SHIFTERD98IN887A125 6 74231 9810111415 16L65982/16PIN CONNECTIONTHERMAL DATAPIN FUNCTIONSymbol ParameterSO16N DIP16Unit R th j-ambThermal Resistance Junction to Ambient12080°C/W Function1C SS Soft Start Timing Capacitor2R fstart Soft Start Frequency Setting -Low Impedance Voltage Source -See also C f 3C f Oscillator Frequency Setting -see also R fmin ,R fstart4R fmin Minimum Oscillation Frequency Setting -Low Impedance Voltage Source -See also C f 5OP out Sense OP AMP Output -Low Impedance 6OP on-Sense Op Amp Inverting Input -High Impedance 7OP on+Sense Op Amp Non Inverting Input -High Impedance 8EN1Half Bridge Latched Enable 9EN2Half Bridge Unlatched Enable 10GND Ground11LVG Low Side Driver Output12V s Supply Volatge with Internal Zener Clamp 13N.C.Not Connected14OUT High Side Driver Reference 15HVG High Side Driver Output 16V bootBootstrapped Supply VoltageCss RfstartCf Rfmin OPOUT OPIN+OPIN-1324567GND V S LVG N.C.OUT HVG VBOOT 16151413121011EN18EN29D98IN888L6598ABSOLUTE MAXIMUM RATINGSSymbol Parameter Value UnitI S Supply Current at V cl(*)25mAV LVG Low Side Output14.6V V OUT High Side Reference-1to V BOOT-18V V HVG High Side Output-1to V BOOT V V BOOT Floating Supply Voltage618VdV BOOT/dt VBOOT pin Slew Rate(repetitive)±50V/ns dV OUT/dt OUT pin Slew Rate(repetitive)±50V/ns V ir Forced Input Voltage(pins Rfmin,Rfstart)-0.3to5V V ic Forced Input Volatge(pins Css,Cf)-0.3to5VV EN1,V EN2Enable Input Voltage-0.3to5VI EN1,I EN2Enable Input Current±3mAV opc Sense Op Amp Common Mode Range-0.3to5V V opd Sense Op Amp Differential Mode Range-5to5V V opo Sense Op Amp Output Voltage(forced) 4.6V T stg Storage Temperature-40to+150°C T j Junction Temperature-40to+150°C T amb Ambient Temperature-40to+125°C (*)The device is provided of an internal Clamping Zener between GND and the Vs pin,It must not be supplied by a low impedance voltage source.Note:ESD immunity for pins14,15and16is guaranteed up to900(Human Body Model).RECOMMENDED OPERATING CONDITIONSSymbol Parameter Value Unit V S Supply Voltage10to V cl V V out(*)High Side Reference-1to Vboot-V cl V V boot(*)Floating Supply Rail500Vf max Maximum Switching Frequency400kHz (*)If the condition Vboot-Vout<18is guaranteed,Vout can range from-3to580V.3/16L65984/16ELECTRICAL CHARACTERISTCS (V S =12V;V BOOT -V OUT =12V;T amb =25°C)SymbolPinParameterTest ConditionMin.Typ.Max.UnitSUPPLY VOLTAGE V suvp 12V S Turn On Threshold 1010.711.4V V suvn V S Turn Off Threshold 7.388.7V V suvh Supply Voltage Under Voltage hysteresis2.7V V cl Supply Voltage Clamping 14.615.616.6V I su Start Up Current V s <V suvn 250µA I qQuiescent Current,fout =60kHz,no loadV s >V suvp2mAHIGH VOLTAGE SECTION I bootleak 16BOOT pin Leakage Current V BOOT =580V 5mA I outleak 14OUT pin Leakage Current V OUT =562V5mA R don16Bootstrap Driver On Resistance150ΩHIGH/LOW SIDE DRIVERS I hvgso 15High Side Driver Source Current V HVG -V OUT =0170250mA I hvgsi High Side Driver Sink Current V HVG -V BOOT =0300450mA I lvgso 11Low Side Driver Source Current V LVG-GND =0170250mA I lvgsi Low Side Driver Sink CurrentV LVG -VS =0300450mA t rise 15,11Low/High Side Output Rise Time C load =1nF80120ns t fallC load =1nF4080nsOSCILLATOR DC 14Output Duty Cycle485052%f min Minimum Output Oscillation FrequencyC f =470pF;R fmin =50k 58.26061.8kHz f start Soft Start Output Oscillation FrequencyC f =470pF;R fmin =50k;R fstart =47k114120126kHz V ref 2,4Voltage to Current Converters Threshold22t d14Dead Time between Low and High Side Conduction0.20.270.35µsTIMING SECTION k ss1Soft Start Timing constantC ss =330nF0.1150.150.185s/µF5/16L6598Figure 1.EN2Timing DiagramsSENSE OP AMP l IB 6,7Input Bias Current 0.1µA V io Input Offset Voltage -1010mV R out 5Output Resistance 200300ΩI out-Source Output Current V out =4.5V 1mA I out+Sink Output CurrentV out =0.2V1mA V ic 6,7OP AMP input common mode range-0.23V GBW Sense Op Amp Gain Band Width Product 1MHz G dcDC Open Loop Gain80dBCOMPARATORS V the18Enabling Comparator Threshold 0.560.60.64V V the29Enabling Comparator Threshold 1.051.2 1.35V t pulse8,9Minimum Pulse lenght200nsSymbolPinParameterTest ConditionMin.Typ.Max.UnitV ST SS f startf minEN2V Cssf OUTT SSD98IN889ELECTRICAL CHARACTERISTCS (continued)L6598Figure2.EN1Timing DiagramsHVGLVGEN1EN2D98IN890Figure3.Oscillator/Output Timing DiagramC fHVGLVGD98IN897High/Low Side driving sectionAn High and Low Side driving Section provide the proper driving to the external Power MOS or IGBT.An high sink/source driving current(450/250mA typ)ensure fast switching times also when size4Power MOS are used. The internal logic ensures a minimum dead time to avoid cross-conduction of the power devices.Timing and Oscillator SectionThe L6598is provided of a soft start function.It consists in a period of time,T SS,in which the switching frequen-cy shifts from f start to f min.This feature is explained in the following description(ref.fig.4and fig.5).6/167/16L6598Figure 4.Soft Start and frequency shifting blockDuring the soft start time the current I SS charges the capacitor C SS ,generating a voltage ramp which is delivered to a transconductance amplifier,as shown in fig.4.Thus this voltage signal is converted in a growing current which is subtracted to I fstart .Therefore the current which drives the oscillator to set the frequency during the soft start is equal to:[1]where [2]At the start-up (t=0)the L6598oscillates at f start ,set by:[3]At the end of soft start (t =T SS )the second term of eq.1decreases to zero and the switching frequency is set only by I min (i.e.R fmin ):[4]Since the second term of eq.1is equal to zero,we have:[5]Note that there is not a fixed threshold of the voltage across C SS in which the soft start finishes (i.e.the end ofthe frequency shifting),and T SS depends on C SS ,I fstart ,g m ,and I SS (eq.5).Making T SS independent of I fstart ,the I SS current has been designed to be a fraction of I fstart ,so:[6]In this way the soft start time depends only on the capacitor C SS .The typical value of the k SS constant (SoftCssIfminIfstart Iss gmOSCIoscI oscI fmin I fstart g m V Css t ()–()+I fmin I fstart g m I ss Css--------------t – +==I fminV REF R fmin -------------I fsart ,V REFR fstart---------------V REF ,2V ===I osc 0()I fmin I fstart +V REF 1R fm in -------------1R fstart----------------+ ==I osc T ss ()I fm in V REFR fmin-------------==I fstart g m I ss C ss --------------T SS –0T SS →C ss I fstart g m I ss------------------------==I SSI fstart K -------------T SS →C ss I fstart g m I fstart K --------------------------T SS →C ss g m K-----------T SS k SS C SS –→===L65988/16Start Timing Constant)is 0.15s/µF.The current I osc is fed to the oscillator as shown in fig.5.It is twice mirrored (x4and x8)generating the triangular wave on the oscillator capacitor C f .Referring to the internal structure of the oscillator (fig.5),a good relationship to compute an approximate value of the oscillator frequency in normal operation is:[7]The degree of approximation depends on the frequency value,but it remains very good in the range from 30kHzto 100kHz (figg.6-10)Figure 5.Oscillator Blockf min 1.41R fmin C f--------------------=X 8X 4Iosc Vth+Vth-S RCf++9/16L6598Figure 6.Typ.fmin vs.Rfmin @Cf =470pFFigure 7.Typ.(fstart-fmin)vs.Rfstar @Cf =470pFFigure 8.Typ.(fstart-fmin)vs.Rfstar @Cf =470pFFigure 9.Typ.(fstart-fmin)vs.Rfstar @Cf =470pFFigure 10.fmin @different Rf vs Cf20406080100R fmin (K Ω)20406080100f min (KHz)D98IN89120406080100R fstart (K Ω)20406080∆f (KHz)Rfmin=33K ΩD98IN89220406080100R fstart (K Ω)20406080100∆f (KHz)Rfmin=50K ΩD98IN89320406080100R fstart (K Ω)20406080100∆f (KHz)Rfmin=100K ΩD98IN894Cf (pF)4002000200400fmin (KHz)Rf=90Kohm -calc.Rf=19.9Ko hm -calc.Rf=90Kohm -meas.Rf=19.9Kohm -meas.L659810/16Bootstrap SectionThe supply of the high voltage section is obtained by means of a bootstrap circuitry.This solution normally re-quires an high voltage fast recovery diode for charging the bootstrap capacitor (fig.11a).In the L6568a patent-ed integrated structure,replaces this external diode.It is realised by means of a high voltage DMOS,driven synchronously with the low side driver (LVG),with in series a diode,as shown in fig.11b.Figure 11.ootstrap driverTo drive the synchronised DMOS it is necessary a voltage higher than the supply voltage Vs.This voltage is obtained by means of an internal charge pump (fig.11b).The diode connected in series to the DMOS has been added to avoid undesirable turn on of it.The introduction of the diode prevents any current can flow from the V boot pin to the V S one in case that the supply is quickly turned off when the internal capacitor of the pump is not fully discharged.The bootstrap driver introduces a voltage drop during the recharging of the capacitor C boot (i.e.when the low side driver is on),which increases with the frequency and with the size of the external power MOS.It is the sum of the drop across the R DSON and of the diode threshold voltage.At low frequency this drop is very small and can be neglected.Anyway increasing the frequency it must be taken in to account.In fact the drop,reducing the amplitude of the driving signal,can significantly increase the R DSON of the external power MOS (and so the dissipation).To be considered that in resonant power supplies the current which flows in the power MOS decreases increas-ing the switching frequency and generally the increases of R DSON is not a problem because power dissipation is negligible.The following equation is useful to compute the drop on the bootstrap driver:[8]where Q g is the gate charge of the external power MOS,R dson is the on resistance of the bootstrap DMOS,and T charge is the time in which the bootstrap driver remains on (about the semiperiod of the switching frequency minus the dead time).The typical resistance value of the bootstrap DMOS is 150Ohm.For example using a power MOS with a total gate charge of 30nC the drop on the bootstrap driver is about 3V,at a switching fre-quency of 200kHz.In fact:To summarise,if a significant drop on the bootstrap driver (at high switching frequency when large power MOSare used)represents a problem,an external diode can be used,avoiding the drop on the R DSON of the DMOS.V S V BOOTLVGC BOOTV OUTV S V BOOTC BOOTV OUTD BOOTa bV drop I ch e arg R dson V diode V drop →+Q g T ch e arg -------------------R dsonV diode +==V drop 30nC 2.23µs------------------150Ω0.6V~2.6V +=11/16OP AMP SectionThe integrated OP AMP is designed to offer Low Output Impedance,wide band,High input Impedance and wide Common Mode Range.It can be readily used to implement protection features or a closed loop control.For this purpose the OP AMP Output can be properly connected to R fmin pin to adjust the oscillation frequency.ComparatorsTwo CMOS comparators are available to perform protection schemes.Short pulses (>=200ns)on Comparators Input are recognised.The EN1input (active High),has a threshold of 0.6V (typical value)forces the L6598in a latched shut down state (e.g.LVG Low,HVG low,Oscillator stopped),as in the Under Voltage Conditions.Nor-mal Operating conditions are resumed after a power-off power-on sequence.The EN2input (active high),with a threshold of 1.2V (typical value)restarts a Soft Start sequence (see Timing Diagrams).In addition the EN2Comparator,when activated,removes a latched shutdown caused by EN1.Figure 12.Switching Time Waveform DefinitionsFigure 13.Dead Time and Duty Cycle Waveform Definition90%90%10%10%t ft rLVG90%90%10%10%t ft rHVGD98IN898LVGHVGt d50%50%t d50%50%T 150%T periodDc =T periodT 1D98IN89912/16Figure 14.Typ.fmin vs.TemperatureFigure 15.Typ.fstart vs.TemperatureFigure 16.Vs thresholds and clamp vs temp.Figure 17.Start Up Current vs TemperatureFigure 18.Quiescent Current vs TemperatureFigure 19.HVG Source and Sink Current vs.Temperature-5005010040506070T(°C)f min (KHz)D98IN895-5050100100110120130T(°C)f fstart (KHz)D98IN896Vs (V)T (°C)-5005010068101214VclampVsuvpVsuvn-5005010010050150200Isu (µA)T (°C)-5050100T (°C)2.32.11.91.71.5Iq @12VIq @VclampIq (mA)-5050100T (°C)200300100400500Ihvg source curr.Ihvg sink curr.Ihvg (mA)13/16Figure 20.LVG Source and Sink Current vs.TemperatureFigure 21.Soft Start Timing Constant vs.Temperature200300100400500Ilvg (mA)-5050100T (°C)Ilvg source curr.Ilvg sink curr.-50050100T (°C)0.140.120.16kss (s/µF)Figure 22.Wide Range AC/DC Adapter ApplicationL656185to 270 VacVoTL431VCO & CONTROLDRIVERL6598ENABLED98IN874A14/16DIP16DIM.mm inch MIN.TYP.MAX.MIN.TYP.MAX.a10.510.020B 0.771.650.0300.065b 0.50.020b10.250.010D 200.787E 8.50.335e 2.540.100e317.780.700F 7.10.280I 5.10.201L 3.30.130Z1.270.050OUTLINE AND MECHANICAL DATA15/16SO16NarrowDIM.mm inch MIN.TYP.MAX.MIN.TYP.MAX.A 1.750.069a10.10.250.0040.009 a2 1.60.063b 0.350.460.0140.018b10.190.250.0070.010C 0.50.020c145°(typ.)D (1)9.8100.3860.394E 5.8 6.20.2280.244e 1.270.050e38.890.350F (1) 3.840.1500.157G 4.6 5.30.1810.209L 0.4 1.270.0160.050M 0.620.024S(1)D and F do not include mold flash or protrusion s.Mold flash or potrusions shall not exceed 0.15mm (.006inch).OUTLINE AND MECHANICAL DATA8°(max.)Information furnished is believed to be accurate and reliable.However,STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use.No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics.Specifications mentioned in this publication are subject to change without notice.This publication supersedes and replaces all information previously supplied.STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.The ST logo is a registered trademark of STMicroelectronics®2000STMicroelectronics-All Rights ReservedSTMicroelectronics GROUP OF COMPANIESAustralia-Brazil-China-Finland-France-Germany-Hong Kong-India-Italy-Japan-Malaysia-Malta-Morocco-Singapore-Spain-Sweden-Switzerland-United Kingdom-U.S.A.16/16。