UC3855BDWTR

Overview

The UC3855BDWTR is a single-phase power factor correction (PFC) controller manufactured by Texas Instruments. It operates within a supply voltage range of 15.0 V to 20 V and supports switching frequencies up to 500 kHz. The device features a maximum duty cycle of 95% and draws an operating supply current of 17 mA. Designed for surface-mount installation, it is housed in a 20-pin SOIC package. The component functions effectively across an ambient temperature range from 0°C to +70°C.

Feature Summary

• Implements average current mode control for high-performance power factor preregulation
• Integrates internal multiplier and error amplifier for precise line regulation
• Features built-in soft-start circuitry to limit inrush current during startup

Applications

• High-power-factor AC-DC power supplies
• Power factor correction preregulators
• Universal input power conversion systems

Procurement Notes

Verify the specific suffix 'DWTR' corresponds to the tape-and-reel packaging format when ordering. Confirm that the SOIC-20 footprint matches your PCB design constraints. Ensure thermal management strategies account for the specified operating temperature limits. Cross-reference the manufacturer part number with official datasheets to avoid confusion with similar variants in the UC385x family.

Selection Notes

Select this component for applications requiring high-efficiency power factor correction with average current mode control. It is suitable for designs needing a maximum switching frequency of 500 kHz. Consider the 20-pin SOIC package size for board space limitations. Evaluate the 15 V to 20 V supply requirement against your system's available rails.

Part Context

This device belongs to the UC385x series of power factor correction controllers from Texas Instruments. These components are designed to improve the efficiency of AC-DC power conversion by shaping the input current to follow the input voltage waveform. The UC3855 variant specifically targets single-phase applications requiring robust performance and simplified external component counts.

Replacement Considerations

The UC3855BDW is the tube-packaged equivalent of this reel-based component. Verify pin compatibility before substituting other PFC controllers from different manufacturers.