TI公司的UCC28810和UCC28811是通用照明電源控制器,能以臨界導通模式控制反激,降壓或升壓轉換器,集成了用于反饋誤差處理的跨導電壓放大器,參考電流發(fā)生器,電流檢測(PWM)比較器,PWM邏輯和用來驅動外接FET的圖騰柱驅動器.主要用在HB LED照明,工業(yè),商業(yè)和住宅區(qū)照明以及室外照明.本文介紹了UCC28810/1主要特性, 方框圖, 簡化應用電路圖以及110W離線AC/DC LED驅動器UCC28810EVM-003主要特性,電路圖,材料清單和PCB布局圖.
The UCC28810 and UCC28811 are general lighting power controllers for low to medium power lumens applications requiring power factor correction and EMC compliance. It is designed for controlling a flyback, buck or boost converter operating in critical conduction mode. It features a transconductance voltage amplifier for feedback error processing, a simple current reference generator for generating a current command proportional to the input voltage, a current-sense (PWM) comparator, PWM logic and a totem-pole driver for driving an external FET.
In the critical conduction mode operation, the PWM circuit is sELf-oscillating with the turn-on being governed by a transformer zero energy detector (TZE pin) and the turn-off being governed by the current sense comparator.
UCC28810/1主要特性:
Transition Mode Controller for Low Implementation Cost of AC Input LED Lighting Applications
Implements Single Stage Power Factor Corrected LED Driver
Enhanced Transient Response With Slew-Rate Comparator
Interfaces with Traditional Wall Dimmers
Accurate Internal VREF for Tight Output Regulation
Two UVLO Options
Overvoltage Protection (OVP), Open-Feedback Protection and Enable Circuits
±750-mA Peak Gate Drive Current
Low Start-Up and Operating Currents
Lead (Pb)-Free Packages
UCC28810/1應用:
AC Input General Lighting Applications Using HB LEDs
Industrial, Commercial and Residential Lighting Fixtures
Outdoor Lighting: Street, Roadway, Parking, Construction and Ornamental LED Lighting Fixtures
圖1. UCC28810/1方框圖
圖2. UCC28810/1簡化應用電路圖
110W離線AC/DC LED驅動器UCC28810EVM-003
The UCC28810EVM-003 is an 110-W offline AC-to-DC LED current driver with power factor correction. This design utilizes a three stage approach with a universal input boost PFC stage, a low-side buck stage providing a controlled current source and a half-bridge DC transformer stage to provide isolation to four LED strings.
This converter was designed to support up to four strings of 15 high brightness LED’s in series (58.5 V max per string). The converter will provide 500-mA average current to each string. The design incorporates an interface for microprocessor control to allow for shutdown into a low power mode (<0.5 W) and PWM dimming of the LED’s.
The boost, buck and DC half bridge multi-transformer stages are included on a UCC28810EVM-003 single board assembly.
UCC28810EVM-003主要特性:
90-VRMS to 265-VRMS Operation
Boost Follower or Fixed Output PFC Stage
PFC Disable
Output Current Disable
External or Internal PWM Dimming
Output Isolated from Line Input
Open Circuit Protection (If one LED string fails open the remaining strings stay on.)
UCC28810EVM-003典型應用:
• AC Input General Lighting Applications Using HB LEDs
• Industrial, Commercial and Residential Lighting Fixtures
• Outdoor Lighting: Street, Roadway, Parking, Construction and Ornamental LED Lighting Fixtures
• LCD TV LED Backlighting
圖3.UCC28810EVM-003外形圖
圖4.UCC28810EVM-003單板裝配圖
UCC28810EVM-003電性能指標:
圖5.UCC28810EVM-003 PFC級電路圖
圖6.UCC28810EVM-003降壓級電路圖
圖7.UCC28810EVM-003 DC變壓器電路圖
UCC28810EVM-003材料清單:
圖8.UCC28810EVM-003 PCB布局圖(上:頂層元件布局,中:頂層銅布線,下:底層銅布線)