UCC38503DW

Overview

The UCC38503DW is a BiCMOS power factor correction and PWM combination controller manufactured by Texas Instruments. It integrates control functions for an active power-factor-corrected preregulator and a second-stage DC-to-DC converter into a single package. The device utilizes average current-mode control to shape the AC input line current waveform, achieving near-unity power factor. The downstream converter employs peak current-mode control for step-down power conversion. It operates within a specified supply voltage range and supports surface-mount installation in a standard SOIC package.

Feature Summary

• Combines PFC and Downstream Converter Control
• Controls Boost Preregulator to Near-Unity Power Factor
• Accurate Power Limiting
• Improved Feedforward Line Regulation

Applications

• Active power-factor-corrected preregulators
• Second-stage DC-to-DC converters
• Power supplies requiring combined PFC and regulation

Procurement Notes

Verify the specific suffix against official documentation to confirm pinout and functional compatibility. Ensure the component meets required environmental operating temperatures and electrical ratings for the target application. Cross-reference with manufacturer datasheets to validate package dimensions and lead configurations before integration.

Selection Notes

Select this component when a single-chip solution for both power factor correction and downstream voltage regulation is required. It is suitable for designs needing near-unity power factor and accurate power limiting. Consider its integrated feedforward capabilities for improved line regulation across varying input voltages.

Part Context

This part belongs to the UCC2850x family of controllers designed for high-performance power supplies. It addresses the need for compact designs by integrating multiple control stages. The technology leverages BiCMOS processes to achieve precise control characteristics and efficient power management in a unified architecture.

Replacement Considerations

UC3854BDW

FAQ

How does the UCC38503DW achieve near-unity power factor?

It shapes the AC input line current waveform to correspond to the AC input-line voltage using average current-mode control.

What control method is used for the second stage?

The second stage uses peak current-mode control to perform the step-down power conversion.