UCC38503N

Overview

The UCC38503N is a BiCMOS combination controller integrating power factor correction (PFC) and downstream DC-to-DC conversion. It employs average current-mode control for the boost preregulator to achieve near-unity power factor and peak current-mode control for the second stage. The device features programmable oscillator, leading-edge modulation for PFC, and trailing-edge synchronization for the PWM stage to minimize output ripple.

Feature Summary

• Combines PFC and downstream converter control in a single IC
• Utilizes average current-mode control for near-unity power factor
• Implements peak current-mode control for step-down power conversion
• Features synchronized second-stage startup with programmable soft-start

Applications

• Active power-factor-corrected preregulators
• Second-stage DC-to-DC converters
• Power supplies requiring near-unity power factor
• Applications with wide input-line voltage ranges

Procurement Notes

Verify component authenticity through authorized Texas Instruments channels or certified distributors. Confirm package integrity and pin alignment against official datasheet specifications. Ensure storage conditions comply with moisture sensitivity level requirements prior to assembly. Cross-reference ordering information with manufacturer documentation to avoid counterfeit components.

Selection Notes

Select this component for designs requiring integrated PFC and DC-to-DC control functions. Consider its capability to handle wide input-line voltage ranges using line feedforward. Evaluate the need for programmable oscillator frequencies and soft-start timing. Assess compatibility with external components for multiplier and filter circuits.

Part Context

Part of the UCC2850x family of BiCMOS controllers designed for high-performance power factor correction and switching regulation. This series integrates advanced control algorithms to reduce external component count and improve efficiency in AC-DC power supply architectures.

Replacement Considerations

UCC28503N