Main Circuits Of High Efficiency PWM Eco-converter Based On HVCMOS

Simple switching power supply management IC was popular used in computer,electronic equipment, communications equipment for its low power consumption,highefficiency, lowest component count switcher solution. Electronic equipment becomessmaller and lower cost, which has been making switching power supply light, small, thin and high efficiency.Based on SinoMOS technology and using Composer and Spectre tools of Cadence EDA,a type of single-chip controller is designed for the fly-back switching power supply of AC/DC. It works at 50kHZ with (PWM),22kHZ in Burst Mode; And the max duty is 80 percent. The power consumption is decrease greatly because Green-mode and powerlimiting is included in this single-chip controller.Green-mode which provides off-time modulation to linearly decrease the workingfrequency under light-load conditions and power limiting which will turn of thetransistor when peak current of inductor reaches the threshold current.This paper introduces the basic theory of fly-back topography andPWM firstly. Then the total structure of the single-chip controller is present according to the functionrequirement and the working theory and the working principle are showed based on its actual application. In chapter three, the all sub-circuits including UVLO, current bias, oscillator, green mode, slop compensation, power limiting, PWM,OVP, blanking time generator, logic controller are designed and simulated.As a result,all of the sub-circuits are satisfied the requirements. The synthetic circuit is also simulated about normal working, green mode working and so on; the results of simulation meet the function requirement.The single-chip designed in this paper is summarized and the development trend ofswitching power supply is introduced at last.