Transition-mode PFC controller - st.com

1 August 2007 Rev 31/2626L6562 ATransition-mode PFC controllerFeatures Proprietary multiplier design for minimum THD Very accurate adjustable output overvoltage protection Ultra-low (30 A) Start-up current Low ( ) quiescent current Digital leading-edge blanking on current sense Disable function on E/A input 1% (@ TJ = 25 C) internal reference voltage -600/+800mA totem pole gate driver with active pull-down during UVLO and voltage clamp DIP-8/SO-8 packagesApplicationsPFC pre-regulators for: IEC61000-3-2 compliant SMPS (Flat TV, monitors, desktop PC, games) HI-END AC-DC adapter/charger up to 400W Electronic ballast Entry level server & web Figure diagram Table 1. Device summaryOrder codesPackagePackagingL6562 ANDIP-8 TubeL6562 ADSO-8 TubeL6562 ADTRSO-8 Tape & ReelContentsL6562A2/26 Contents1 Description.

2 32 Pin settings .. connection .. description .. 43 Maximum ratings .. 54 Thermal data .. 55 Electrical characteristics .. 66 Typical electrical characteristic .. 97 Application information .. protection .. function .. optimizer circuit .. with no auxiliary winding on the boost inductor .. between the L6562A and the L6562 .. 178 Application examples and ideas .. 189 Package mechanical data .. 2210 Revision history .. 25L6562 ADescription 3/261 Description The L6562A is a current-mode PFC controller operating in Transition Mode (TM). Coming with the same pin-out as its predecessors L6561 and L6562, it offers improved highly linear multiplier includes a special circuit, able to reduce AC input current distortion, that allows wide-range-mains operation with an extremely low THD, even over a large load range.

3 The output voltage is controlled by means of a voltage-mode error amplifier and an accurate (1% @TJ = 25 C) internal voltage reference . The device features extremely low consumption (60 A max. before start-up and <5 mA operating) and includes a disable function suitable for IC remote ON/OFF, which makes it easier to comply with energy saving requirements (Blue Angel, EnergyStar, Energy2000, etc.).An effective two-step OVP enables to safely handle overvoltages either occurring at start-up or resulting from load totem-pole output stage, capable of 600 mA source and 800 mA sink current, is suitable to drive high current MOSFETs or IGBTs. This, combined with the other features and the possibility to operate with the proprietary Fixed-Off-Time control, makes the device an excellent low-cost solution for EN61000-3-2 compliant SMPS in excess of 350W.

4 Pin settingsL6562A4/26 2 Pin settings Pin connectionFigure connection (top view) Pin description ZCDINVCOMPMULTCSVccGDGND12348765 Table 2. Pin description Pin N NameDescription1 INVI nverting input of the error amplifier. The information on the output voltage of the PFC pre-regulator is fed into this pin through a resistor divider. The pin doubles as an ON/OFF control of the error amplifier. A compensation network is placed between this pin and INV to achieve stability of the voltage control loop and ensure high power factor and low THD. 3 MULTMain input to the multiplier. This pin is connected to the rectified mains voltage via a resistor divider and provides the sinusoidal reference to the current loop.

5 4 CSInput to the PWM comparator. The current flowing in the MOSFET is sensed through a resistor, the resulting voltage is applied to this pin and compared with an internal sinusoidal-shaped reference , generated by the multiplier, to determine MOSFET s turn-off. The pin is equipped with 200 ns leading-edge blanking for improved noise inductor s demagnetization sensing input for Transition-mode operation. A negative-going edge triggers MOSFET s Current return for both the signal part of the IC and the gate driver output. The totem pole output stage is able to drive power MOSFET s and IGBT s with a peak current of 600 mA source and 800 mA sink. The high-level voltage of this pin is clamped at about 12V to avoid excessive gate voltages in case the pin is supplied with a high Vcc.

6 8 VccSupply Voltage of both the signal part of the IC and the gate driver. The supply voltage upper limit is extended to 22V min. to provide more headroom for supply voltage changes. L6562 AMaximum ratings 5/263 Maximum ratings4 Thermal dataTable 3. Absolute maximum ratingsSymbolPinParameterValueUnitVCC8IC supply voltage (ICC 20mA)Self-limitedVIGD7 Output totem pole peak currentSelf-limitedA---1 to 4 Analog inputs & to 8 VIZCD5 Zero current detector max. current 10mATable 4. Thermal dataSymbolParameterValueUnitSO8 DIP8 RthJAMax. Thermal Resistance, Junction-to-ambient150100 C/WPTOTP ower Dissipation @TA = 50 Temperature Operating range-40 to 150 CTSTGS torage Temperature-55 to 150 CElectrical characteristicsL6562A6/26 5 Electrical characteristicsTable 5.

7 Electrical characteristics ( -25 C < TJ < +125 C, VCC = 12V, Co = 1nF; unless otherwise specified)Symbol Parameter Test condition MinTypMaxUnitSupply voltageVCCO perating rangeAfter threshold(1) threshold(1) VoltageICC = currentIstart-upStart-up currentBefore turn-on, VCC = 11V3060 AIqQuiescent currentAfter supply current @ currentDuring OVP (either static or dynamic) or VINV inputIMULTI nput bias currentVMULT = 0 to 4V-1 AVMULTL inear operation range0 to 3 VOutput max. slopeVMULT = 0 to 1V, VCOMP = Upper (2)VMULT = 1V, VCOMP= 4V, amplifierVINVV oltage feedback input thresholdTJ = 25 < VCC < (1) regulationVCC = to bias currentVINV = 0 to 3V-1 AGvVoltage gainOpen loop6080dBGBGain-bandwidth product1 MHzICOMPS ource currentVCOMP = 4V, VINV = currentVCOMP = 4V, VINV = VMULT ---------------------L6562 AElectrical characteristics 7/26 Symbol Parameter Test condition MinTypMaxUnitVCOMPU pper clamp voltageISOURCE = clamp voltageISINK = (1)

8 VVINVdisDisable threshold150200250mVVINVenRestart threshold380450520mVOutput overvoltageIOVPD ynamic OVP triggering AHysHysteresis(3)20 AStatic OVP threshold(1) VCurrent sense comparatorICSI nput bias currentVCS = 0-1 AtLEBL eading edge blanking100200300nstd(H-L)Delay to output175nsVCS Current sense clampVCOMP = Upper clamp, Vmult = sense offsetVMULT = 0 25mVVMULT = 5 Zero current detectorVZCDHU pper clamp voltageIZCD = clamp voltageIZCD = - voltage(positive-going edge)(3) voltage(negative-going edge)(3) bias currentVZCD = 1 to AIZCDsrcSource current current timer period75190300 sTable 5. Electrical characteristics (continued)( -25 C < TJ < +125 C, VCC = 12V, Co = 1nF; unless otherwise specified)Electrical characteristicsL6562A8/26 Symbol Parameter Test condition MinTypMaxUnitGate driverVOLO utput low voltageIsink = high voltageIsource = source sink fall time3070nstrVoltage rise time60110nsVOclampOutput clamp voltageIsource = 5mA; Vcc = 20 V101215 VUVLO saturationVcc = 0 to VCCon, Isink = 2 All the parameters are in tracking2.

9 The multiplier output is given by: 3. Parameters guaranteed by design, functionality tested in 5. Electrical characteristics (continued)( -25 C < TJ < +125 C, VCC = 12V, Co = 1nF; unless otherwise specified)() VCOMPMULTcs = L6562 ATypical electrical characteristic 9/266 Typical electrical characteristic Figure current vs supply voltageFigure & UVLO vs TJ Figure consumption vs TJFigure 6. Vcc Zener voltage vs TJ (V)Icc (mA)Co = 1 nFf = 70 kHzTj = 25 Cpj910111213-50050100150Tj ( C)(V) ( C)Icc (mA)Before start-upDisabled or during OVPQ uiescentOpe r atingVcc = 12 VCo= 1 nFf = 70 kHz22232425262728-50050100150Tj ( C)VccZ (V)Typical electrical characteristicL6562A10/26 Figure reference vs TJFigure current vs TJ Figure output clamp levels vs TJFigure 10.

10 Delay-to-output vsTJ ( C)VREF (V)Vcc = 12Vj23242526272829303132333435-500501001 50Tj ( C)Iovp (uA)Vcc = 12V123456-50050100150Tj ( C)V COMP pin2 (V)Vcc = 12 VUppe r cla mpLower clamp0100200300-50050100150Tj ( C)tD (H-L) (ns)Vcc = 12VL6562 ATypical electrical characteristic 11/26 Figure 11. Multiplier characteristicFigure 12. Vcs clamp vs TJ Figure 13. ZCD clamp levels vs TJFigure 14. Start-up timer vs TJ (pin3) (V)Vcs (pin4) (V)V COMP (pin2) (V)Upper Volt. V3 ( C)Vcsx (V)Vcc = 12 VVCOMP = Upper clamppj-101234567-50050100150Tj ( C)Vzcd (V)Vcc = 12 VIZCD = mAUppe r cla mpLower clamppj150160170180190200-50050100150Tj ( C)Tstart (us)Vcc = 12 VTypical electrical characteristicL6562A12/26 Figure 15.