本文介绍了UCC28070 主要特性，简化方框图和功能方框图，以及采用两个UCC28070的四相输出应用框图，300W交叉PFC预稳压器参考设计主要指标，控制器电路图和电源电路图。

UCC28070是先进的功率因素修正器件，集成了两个工作在180度反相的PWM。 这种PWM交叉工作能降低输入和输出纹波电流，使得导电EMI滤波变得更加容易，成本更低。可编程工作频率从30 kHz 到300 kHz，有极好的效率和多种保护功能，主要用在高效服务器和台式PC电源，通信整流器，白色家电和工业设备。

UCC28070 主要特性：

Interleaved Average Current-Mode PWM Control

with Inherent Current Matching

Advanced Current Synthesizer Current Sensing for

Superior Efficiency

Highly-Linear Multiplier Output with Internal Quantized

Voltage Feed-Forward Correction for Near-Unity PF

Programmable Frequency (30 kHz to 300 kHz)

Programmable Maximum Duty-Cycle Clamp

Programmable Frequency Dithering Rate and Magnitude

for Enhanced EMI Reduction

Magnitude: 3 kHz to 30 kHz

Rate: Up to 30 kHz

External Clock Synchronization Capability

Enhanced Load and Line Transient Response through Voltage

Amplifier Output Slew-Rate Correction

Programmable Peak Current Limiting

Bias-Supply UVLO, Over-Voltage Protection, Open-Loop Detection,

and PFC-Enable Monitoring

External PFC-Disable Interface

Open-Circuit Protection on VSENSE and VINAC pins

Programmable Soft Start

20-Lead TSSOP/SOIC Packages

UCC28070 应用：

High-Efficiency Server and Desktop Power Supplies

Telecom Rectifiers

White Goods and Industrial Equipment

图1。UCC28070简化方框图

图2。UCC28070功能方框图

图3。采用两个UCC28070的四相输出应用框图