UC3843A Fairchild SMPS Controller Data Sheet

Download Datasheet for Fairchild Semiconductor UC3843A SMPS Controller [8 pages Rev.5.0 2000 pdf/zip]

SKU: UC3843AFAIRCHILDDS2000REV5 Category: Brand:

Description

The UC3843A is a fixed PWM controller for Off-Line and DC to DC converter applications. The internal circuits include UVLO, low start up current circuit, temperature compensated reference, high gain error amplifier, current sensing comparator, and high current totem-pole output for driving a POWER MOSFET. Also UC3843A provide low start up current below 0.3mA and short shutdown delay time typ. 100ns. The UC3843A has UVLO threshold of 8.4V(on) and 7.6V(off). The UC3843A can operate within 100% duty cycle.

FEATURES
– Low Start Current 0.2mA (typ)
– Operating Range Up To 500KHz
– Cycle by Cycle Current Limiting
– Under Voltage Lock Out With Hysteresis
– Short Shutdown Delay Time: typ.100ns
– High Current Totem-pole Output
– Output Swing Limiting: 22V

DATASHEET CONTAINS:

INTERNAL BLOCK DIAGRAM

UC3843A PINOUT

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS
– Reference Section
– Osillator Section
– Current Sense Section
– Error Amplifier Section
– Output Section
– Under Voltage Lockout Section
– PWM Section
– Total Standby Current

MECHANICAL DIMENSIONS

ORDERING INFORMATION