UCC38503DWG4

Overview

The UCC38503DWG4 is a BiCMOS PFC and PWM combination controller from Texas Instruments, designed for active power-factor-corrected preregulators and second-stage DC-to-DC converters. It integrates average current-mode control for near-unity power factor and peak current-mode control for step-down conversion. The device features leading-edge modulation for the PFC stage and trailing-edge synchronization for the second stage to minimize output ripple. It includes line feedforward capabilities using IAC and an external filter to maintain constant input power across wide voltage ranges.

Feature Summary

• Combines PFC and downstream converter controls in a single IC
• Achieves near-unity power factor via average current-mode control
• Utilizes peak current-mode control for efficient step-down power conversion
• Incorporates line feedforward (VFF) to reduce external component count

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 the exact suffix against the manufacturer's official documentation to confirm package type and temperature range specifications. Ensure compatibility with your design requirements for lead-free processing and RoHS compliance standards before finalizing procurement decisions.

Selection Notes

Select this component when a combined PFC and PWM solution is required to simplify the bill of materials. It is suitable for designs needing high power factor correction and efficient downstream regulation without separate controllers. Consider the integrated line feedforward feature for cost-sensitive applications requiring fewer external components.

Part Context

This part belongs to the UCC2850x family of controllers, which are engineered to provide comprehensive control functions for AC-DC power conversion systems. The family is characterized by its ability to handle both power factor correction and secondary DC-DC conversion within a unified architecture, streamlining the design process for modern power supplies.

Replacement Considerations

Consult the manufacturer's datasheet for officially recommended substitutes or pin-compatible alternatives. Verify that any replacement maintains the same functional characteristics, including control modes and modulation types, to ensure circuit performance remains unchanged.