基于UCC28070设计的300W PFC高效电源方案

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[p]

UCC28070 300W交叉PFC预稳压器参考设计

UCC28070 300-W Interleaved PFC Pre-Regulator Design Review

In higher power applications to utilize the full line power and reduce line current harmonics PFC Pre-regulators are generally required. In these high power applications interleaving PFC stages can reduce inductor volume and reduce input and output capacitor ripple current. This results in smaller overall magnetic volume and filter capacitor volume increasing the converters overall power density. This is made possible through distributing the power over two interleaved boost converters and the inductor ripple current cancellation that occurs with interleaving, reference [5]. This application note will review the design of a 300W two-phase interleaved power factor corrected (PFC) pre-regulator. This power converter achieves PFC with the use of the UCC28070 interleaved PFC controller, reference。

参考设计指标：



图4。典型平均电流模式交叉PFC预稳压器电路图

图5。300W原型子板控制器电路图

图6。300W原型主板电源电路图