基于TOP266EG的27W LCD监视器电源设计方案

TOPSwitch-JX 系列TOP266EG是高性价比器件，它集成了725V　功率MOSFET，高压开关电流源，多模式PWM控制，振荡器，热关断电路，故障保护以及其它控制电路．265 VAC时无负载的功耗低于100 mW，工作频率132 kHz，降低了变压器尺寸和电源的体积．本文介绍了TOPSwitch-JX 系列主要特性，产品亮点，功能方框图，以及65W 19V和30W 12V通用输入反激电源电路图，27W LCD监视器电源参考设计主要指标，电路图以及所用材料清单(BOM)．

    Power Supply Using TOP266EG
    90 VAC–265 VAC Input; 5V, 2.5A and　14.5V, 1A Outputs
    Application LCD Monitor
  
    TOPSwitch-JX cost effectively incorporates a 725 V power MOSFET, high voltage switched current source, multi-mode PWM control, oscillator, thermal shutdown circuit, fault protection and other control circuitry onto a monolithic device.
  
    TOP266EG产品亮点：
  
    · EcoSmart® - Energy Efficient
  
    · Energy efficient over entire load range
  
    · No-load consumption below 100 mW at 265 VAC
  
    · Up to 750 mW standby output power for 1 W input at 230 VAC High Design Flexibility for Low System Cost
  
    · Multi-mode PWM control maximizes efficiency at all loads
  
    · 132 kHz operation reduces transformer and power supply size
  
    · 66 kHz option for highest efficiency requirements
  
    · Accurate programmable current limit
  
    · Optimized line feed-forward for line ripple rejection
  
    · Frequency jittering reduces EMI filter cost
  
    · Fully integrated soft-start for minimum startup stress
    · 725 V rated MOSFET
  
    · Simplifies meeting design derating requirements Extensive Protection Features
  
    · Auto-restart limits power delivery to <3% during overload faults
  
    · Output short-circuit protection (SCP)
  
    · Output over-current protection (OCP)
  
    · Output overload protection (OPP)
  
    · Output overvoltage protection (OVP)
  
    · User programmable for hysteretic/latching shutdown
  
    · Simple fast AC reset
  
    · Primary or secondary sensed
  
    · Line undervoltage (UV) detection prevents turn-off glitches
  
    · Line overvoltage (OV) shutdown extends line surge withstand
  
    · Accurate thermal shutdown with large hysteresis (OTP) Advanced Package Options
  
    · eDIP&trade;-12 package:
  
    · Low profile horizontal orientation for ultra-slim designs
  
    · Heat transfer to both PCB and heat sink
  
    · Optional external heat sink provides thermal impedance equivalent to a TO-220
  
    · eSIP&reg;-7C package:
  
    · Vertical orientation for minimum PCB footprint
  
    · Simple heat sink mounting using clip provides thermal impedance equivalent to a TO-220
  
    · Extended creepage to DRAIN pin
  
    · Heat sink is connected to SOURCE for low EMI

      
   
  
    图１．TOP266EG 功能方框图(E和V封装)
  
   
  
    图２．采用TOP266EG的65W 19V通用输入反激电源电路图
  
   
  
    图３．采用TOP266EG的30W 12V通用输入反激电源电路图
  
    27W LCD监视器电源设计方案
  
    This document is an engineering report describing a 5 V / 2.5 A, 14.5 V / 1 A power supply utilizing a TOP266EG. The TOP266EG is part of the TOPSwitch-JX IC family from Power Integrations. The document contains the power supply specification, schematic, bill of materials, transformer documentation, printed circuit layout, and performance data.

      
  
  

  图４．27W LCD监视器电源参考设计外形图
    
       27W LCD监视器电源参考设计指标：
   
      
   
   
   
        图５．27W LCD监视器电源参考设计电路图
   
  



      
   
  
  图６．参考设计中的变压器电方框图
    
   
       27W LCD监视器电源参考设计材料清单（ＢＯＭ）：


  
  


  
  

  图７．27W LCD监视器电源参考设计ＰＣＢ布局图