UCC38502DW

Overview

The UCC38502DW is a BiCMOS Power Factor Correction (PFC) and PWM combination controller manufactured by Texas Instruments, originally developed by Unitrode. It integrates average current mode PFC control with a post-regulating PWM controller in a single package. The device operates within a supply voltage range of 9.7V to 18V and supports switching frequencies up to 120kHz. It features a maximum start-up current of 150µA and functions reliably across an industrial temperature range of -40°C to 85°C. The component is housed in a 20-pin SOIC package.

Feature Summary

• Integrates average current mode PFC control with a post-regulating PWM controller for combined power factor correction and DC-DC conversion.
• Utilizes BiCMOS technology to achieve low start-up current and reduced static operating power consumption.
• Supports synchronous operation between the PFC stage and the downstream PWM converter.

Applications

• Power factor correction pre-regulators for AC-DC converters
• Combined PFC and DC-DC power supply architectures
• Telecommunications power systems requiring high efficiency

Procurement Notes

Verify the manufacturer origin carefully, as the UCC38502 series was originally designed by Unitrode before its acquisition by Texas Instruments. Ensure the specific suffix matches the required packaging format, such as tape-and-reel or tube configurations. Confirm that the device meets RoHS compliance standards if required for the target application environment.

Selection Notes

Select this component when a single-chip solution for both power factor correction and secondary regulation is required. It is suitable for designs prioritizing average current mode control to achieve near-unity power factors. Consider the 20-SOIC package constraints and the 120kHz maximum frequency limit during thermal and layout planning.

Part Context

The UCC38502 belongs to the UCC38500/01/02/03 family of combination controllers. These devices were pioneered by Unitrode to simplify power supply designs by merging PFC and PWM functions. The UCC38502 specifically offers a fixed switching frequency configuration compared to other variants in the series.

Replacement Considerations

The UCC28502DW serves as a direct functional equivalent within the same product family. Both devices share identical pinouts and core control logic, differing primarily in manufacturing lot or minor suffix variations.