UNISONIC TECHNOLOGIES CO., LTD

UC3842B/3843B

LINEAR INTEGRATED CIRCUIT

www.unisonic.com.tw

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Copyright © 2008 Unisonic Technologies Co., Ltd

QW-R103-012.D

HIGH PERFORMANCE

CURRENT MODE

CONTROLLERS

DESCRIPTION

The UTC UC3842B/3843B are specifically designed for off-line

and dc-to-dc converter applications offering the designer a

cost-effective solution with minimal external components.

The UC3842B has UVLO thresholds 16V (on) and 10V(off),

ideally suited for off-line converters. The UC3843B is tailored for

lower voltage applications having UVLO thresholds of 8.4V(on)

and 7.6V(off).

FEATURES

* Trimmed oscillator for precise frequency control

* Oscillator frequency guaranteed at 250kHz

* Current mode operation to 500kHz

* Automatic feed forward compensation

* Latching PWM for cycle-by-cycle current limiting

* Internally trimmed reference with undervoltage lockout

* High current totem pole output

* Undervoltage lockout with hysteresis

* Low startup and operating current

Lead-free:

UC3842BL

UC3843BL

Halogen-free: UC3842BP

UC3843BP

ORDERING INFORMATION

Ordering Number

Normal

Lead Free

Halogen Free

Package

Packing

UC3842B-D08-T

UC3842BL-D08-T

UC3842BP-D08-T

DIP-8

Tube

UC3842B-S08-R

UC3842BL-S08-R

UC3842BP-S08-R

SOP-8

Tape Reel

UC3843B-D08-T

UC3843BL-D08-T

UC3843BP-D08-T

DIP-8

Tube

UC3843B-S08-R

UC3843BL-S08-R

UC3843BP-S08-R

SOP-8

Tape Reel