1FEATURES

• Automatic Feed-Forward Compensation

• Programmable Pulse-by-Pulse Current

Limiting

• Automatic Symmetry Correction in Push-Pull

Configuration

• Enhanced Load-Response Characteristics

• Parallel Operation Capability for Modular

Power Systems

• Differential Current-Sense Amplifier With Wide

Common-Mode Range

• Double Pulse Suppression

• Undervoltage Lockout

• Soft-Start Capability

• Shutdown Terminal

DESCRIPTION

The UC1846 control IC provides all of the necessary features to implement fixed-frequency, current-mode control

schemes, while maintaining a minimum external parts count. The superior performance of this technique can be

measured in improved line regulation, enhanced load-response characteristics, and a simpler, easier-to-design

control loop. Topological advantages include inherent pulse-by-pulse current-limiting capability, automatic

symmetry correction for push-pull converters, and the ability to parallel power modules, while maintaining equal

current sharing.

Protection circuitry includes built-in undervoltage lockout and programmable current limit, in addition to soft-start

capability. A shutdown function is also available, which can initiate either a complete shutdown with automatic

restart or latch the supply off.

Other features include fully latched operation, double pulse suppression and deadline adjust capability.

The UC1846 features low outputs in the OFF state.