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.

2 Device summaryOrder codesPackagePackagingL6562 ANDIP-8 TubeL6562 ADSO-8 TubeL6562 ADTRSO-8 Tape & ReelContentsL6562A2/26 Contents1 Description .. 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.

3 178 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.

4 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.

5 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. 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.

6 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. 4 CSInput to the PWM comparator.

7 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.

8 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. 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.

9 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.

10 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.