The Design Of AC/DC Switching Power Supply Management IC Based On BiCMOS Technology

Single-chip switching power supply management Integrated Circuit(IC) has shown strong vital energies since it came out in the 1990's,because the IC has many virtues such as high integration level,most cost effective,lowest component count switcher solution and high performance.The switching power IC is selected firstly in the design of high power switching power supply,precision switching power supply,application specific switching power supply and so on in the world,which has been making switching power supply short,small,light and thin.BiCMOS(Bipolar Complementary Metal-xide-Semieonduetor) technology combines bipolar device with CMOS device effectively,so it not only holds CMOS circuit's virtues,but also obtain bipolar circuit's merits.So the IC industry are increasingly attaching much importance to the new technology in recent years.A type of single-chip switching power supply management IC is designed for the switching power supply of AC/DC.It integrates low-voltage control portion such as PWM comparator,voltage reference circuit,sawtooth-wave generator,error amplifier,Soft activation circuit etc,and high-voltage power tube in the same Integrated Circuit.Adopting BiCMOS technology improves the performance of IC.In this paper,the sub-circuits are designed and emulated carefully using HSPICE and as result,the sub-circuit answer the requirements that was setted in advance.It works at high freqency with pulse width modulation(PWM) mode and the normal working temperature is 0℃～78℃;the working frequency is fixed at 130kHz.So far as the output signal of the single-chip IC is concerned,the maximun time proportion of its high level is 72 percent,but the minmum one is 8.5 percent,Conversion rate can reach the 87 percent.Lastly,the synthetic circuit is emulated about power-up working,normal working,automatic restart working and over-current working;the results of emulation meet the function requirement.The forward design of Single-chip switching power supply management IC has been finished.This management IC can be used in middle or low power switching power supply.