本文介紹了UCC28070 主要特性，簡化方框圖和功能方框圖，以及采用兩個UCC28070的四相輸出應(yīng)用框圖，300W交叉PFC預(yù)穩(wěn)壓器參考設(shè)計主要指標，控制器電路圖和電源電路圖。

UCC28070是先進的功率因素修正器件，集成了兩個工作在180度反相的PWM。 這種PWM交叉工作能降低輸入和輸出紋波電流，使得導電EMI濾波變得更加容易，成本更低。可編程工作頻率從30 kHz 到300 kHz，有極好的效率和多種保護功能，主要用在高效服務(wù)器和臺式PC電源，通信整流器，白色家電和工業(yè)設(shè)備。

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 應(yīng)用：

High-Efficiency Server and Desktop Power Supplies

Telecom Rectifiers

White Goods and Industrial Equipment

圖1。UCC28070簡化方框圖

圖2。UCC28070功能方框圖

圖3。采用兩個UCC28070的四相輸出應(yīng)用框圖

UCC28070 300W交叉PFC預(yù)穩(wěn)壓器參考設(shè)計

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。

參考設(shè)計指標：

圖4。典型平均電流模式交叉PFC預(yù)穩(wěn)壓器電路圖

圖5。300W原型子板控制器電路圖

圖6。300W原型主板電源電路圖

[1].UCC28070 datasheethttp://www.dzsc.com/datasheet/UCC28070+_1137169.html.
[2].PFCdatasheethttp://www.dzsc.com/datasheet/PFC_1200255.html.