L4981A ® L4981B
POWER FACTOR CORRECTOR
CONTROL BOOST PWM UP TO 0.99P.F. LIMIT LINE CURRENT DISTORTION TO < 5% UNIVERSAL...
L4981A ® L4981B
POWER FACTOR CORRECTOR
CONTROL BOOST PWM UP TO 0.99P.F. LIMIT LINE CURRENT DISTORTION TO < 5% UNIVERSAL INPUT MAINS FEED FORWARD LINE AND LOAD REGULATION AVERAGE CURRENT MODE PWM FOR MINIMUM NOISE SENSITIVITY HIGH CURRENT BIPOLAR AND DMOS TOTEM POLE OUTPUT LOW START-UP CURRENT (0.3mA TYP.) UNDER
VOLTAGE LOCKOUT WITH HYSTERESIS AND PROGRAMMABLE TURN ON THRESHOLD OVER
VOLTAGE, OVERCURRENT PROTECTION PRECISE 2% ON CHIP REFERENCE EXTERNALLY AVAILABLE SOFT START
DESCRIPTION
The L4981 I.C. provides the necessary features to achieve a very high power factor up to 0.99. Realized in BCD 60II technology this power factor corrector (PFC) pre-regulator contains all the con-
BLOCK DIAGRAM
MULTIPOWER BCD TECHNOLOGY
DIP20
SO20
ORDERING NUMBERS: L4981X (DIP20) L4981XD (SO20)
trol functions for designing a high efficiency-mode power supply with sinusoidal line current consumption. The L4981 can be easily used in systems with mains
voltages between 85V to 265V without any line switch. This new PFC offers the possibility to work at fixed frequency (L4981A) or modulated frequency (L4981B) optimizing the size of the in-
November 2001
1/16
L4981A - L4981B
put filter; both the operating frequency modes working with an average current mode PWM controller, maintaining sinusoidal line current without slope compensation. Besides power
MOSFET gate driver, precise
voltage reference (externally available), error amplifier, under
voltage lockout, current sense and the
soft start are...