UC3842G_08

UNISONIC TECHNOLOGIES CO., LTD UC3842G HIGH PERFORMANCE CURRENT MODE CONTROLLER ■ DESCRIPTION LINEAR INTEGRATED CIRCUIT The UTC UC3842G of high performance current mode controller is specifically designed for off-line and DC-to-DC converter applications offering the designer a cost effective solution with minimal external components. This integrated circuit features approximately 300μA start up current, a precision reference trimmed the error amplifier input. Also included are protective features consisting of input and reference undervoltage lockouts each with hysteresis, cycle-by-cycle current limiting, and so on. ■ FEATURES Lead-free: UC3842GL Halogen-free: UC3842GP * Low startup and operating current * User defined switching frequency(Norm is 52kHz) * Power-saving mode for low power * Under voltage lockout with hysteresis * Over voltage protection * Latching PWM for Cycle-By-Cycle current limiting * Internally trimmed reference with undervoltage lockout ORDERING INFORMATION Normal UC3842G-S08-R UC3842G-S08-T UC3842G-D08-T Ordering Number Lead Free UC3842GL-S08-R UC3842GL-S08-T UC3842GL-D08-T Halogen Free UC3842GP-S08-R UC3842GP-S08-T UC3842GP-D08-T Package SOP-8 SOP-8 DIP-8 Packing Tape Reel Tube Tube www.unisonic.com.tw Copyright © 2008 Unisonic Technologies Co., Ltd 1 of 8 QW-R103-036.B UC3842G PIN CONFIGURATION LINEAR INTEGRATED CIRCUIT COMP 1 8 VREF FB 2 7 VCC CS 3 6 OUT CT 4 5 GND ■ PIN DESCRIPTION PIN NAME COMP FB CS CT GND OUT VCC VREF I/O O I I I O O Function This pin is error amplifier output The error amplifier inverting input Current sense input The capacitor controlling switch frequency Ground Output to the gate of external power MOS Supply voltage Inter 5V reference voltage output PIN NO. 1 2 3 4 5 6 7 8 UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 8 QW-R103-036.B UC3842G ■ BLOCK DIAGRAM LINEAR INTEGRATED CIRCUIT UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 8 QW-R103-036.B UC3842G ABSOLUTE MAXIMUM RATINGS (Ta＝25°C) LINEAR INTEGRATED CIRCUIT PARAMETER SYMBOL RATINGS UNIT Supply Voltage (Low Impedance Source) VCC 30 V Supply Voltage (ICC