L4981AD STMicroelectronics

L4981A L4981B POWER FACTOR CORRECTOR CONTROL BOOST PWM UP TO 0.99P.F. MULTIPOWER BCD TECHNOLOGY LIMIT LINE CURRENT DISTORTION TO < 5% UNIVERSAL INPUT MAINS FEED FORWARD LINE AND LOAD REGULA- TION AVERAGE CURRENT MODE PWM FOR MINIMUM NOISE SENSITIVITY HIGH CURRENT BIPOLAR AND DMOS TO- TEM POLE OUTPUT LOW START-UP CURRENT (0.3mA TYP.) DIP20 SO20 UNDER VOLTAGE LOCKOUT WITH HYS- TERESIS AND PROGRAMMABLE TURN ON THRESHOLD ORDERING NUMBERS: L4981X (DIP20) L4981XD (SO20) OVERVOLTAGE, OVERCURRENT PROTEC- TION PRECISE 2% ON CHIP REFERENCE EX- TERNALLY AVAILABLE SOFT START trol functions for designing a high efficiency-mode power supply with sinusoidal line current con- sumption. DESCRIPTION The L4981 can be easily used in systems with The L4981 I.C. provides the necessary features mains voltages between 85V to 265V without any to achieve a very high power factor up to 0.99. line switch. This new PFC offers the possibility to Realized in BCD 60II technology this power factor work at fixed frequency (L4981A) or modulated corrector (PFC) pre-regulator contains all the con- frequency (L4981B) optimizing the size of the in- BLOCK DIAGRAM 1/16 November 2001L4981A - L4981B put filter both the operating frequency modes soft start are included. To limit the number of the working with an average current mode PWM con- external components, the device integrates pro- troller, maintaining sinusoidal line current without tections as overvoltage and overcurrent. The slope compensation. overcurrent level can be programmed using a Besides power MOSFET gate driver, precise volt- simple resistor for L4981A. For a better precision age reference (externally available), error ampli- and for L4981B an external divider must be used. fier, undervoltage lockout, current sense and the ABSOLUTE MAXIMUM RATINGS Symbol Pin Parameter Value Unit VCC 19 Supply Voltage (ICC 50mA) (*) selflimit V IGDRV 20 Gate driv. output peak current (t = 1s) SINK 2 . SOURCE 1.5 A VGDRV Gate driv. output voltage t = 0.1s-1V Voltages at pins 3, 14, 7, 6, 12, 15 -0.3 to 9 V VVA-OUT 13 Error Amplifier Voltage -0.3 to 8.5 V IAC 4 AC Input Current 5 mA Voltages at pin 8, 9 -0.5 to 7 V VCA-OUT 5 Current Amplifier Volt. (Isource = -20mA Isink = 20mA) -0.3 to 8.5 V VROSC 17 Voltage at pin 17 -0.3 to 3 V 11, 18 Voltage at pin 11, 18 -0.3 to 7 V ICOSC 18 Input Sink Current 15 mA IFREQ-MOD 16 Frequency Modulation Sink Current (L4981B) 5 mA VSYNC 16 Sync. Voltage (L4981A) -0.3 to 7 V VIPK 2 Voltage at pin 2 -0.3 to 5.5 V Voltage at Pin 2 t = 1s -2 V Ptot Power Dissipation at T = 70C (DIP20) 1 W amb Power Dissipation at T = 70C (SO20) 0.6 W amb T Operating Ambient Temperature -40 to 125 C op Tstg StorageTemperature -55 to 150 C (*) Maximum package power dissipation limits must be observed. PIN CONNECTIONS (Top views) L4981A L4981B 2/16