智能开关电源集成电路TO PSw itch 的分析

近年来，由于便携设备的增多，对供电单元电路小型化的要求越来越迫切，各国政府对电源系统环保，节能的要求也更加严格，这些都要求有效率更高，集成度更高的开关电源加以配合，本文反向剖析了美国Power Integration公司的TOPSwitch系列智能开关电泊集成电路芯片，在系统地分析及全面的计算机仿真的基础之上，给出该电路的工作原理，设计方法及其应用，该集成电路除了一般的PWM控制功能外，还集成了自动重启功能，过渡，过热保护功能，大功能MOSFET等，具有效率高AC／DC转换效率可高达90％，外围元件少等特点，具有多项专利，是目前国际上最先进的智能开关电源产品之一，该电路的芯片生产工艺，更是集高压（700V）大功率（数十瓦），数模混合，双极／CMOS兼容等最先进的半导体技术于一体，世界上目前只有少数几家公司具有生产该类电路的能力。

Analysis of Smart Power IC TOPSwitch

Recent progress on electronic systems is forcing higher level integration in switching-power-supply chips. The most notable requirements are those involving size, weight and energy efficiency. New government energy-efficiency programs are further reshaping switching-power-supply designs. One of the first integrated switchers on the market was Power Integrations′ Topswitch family. The devices combine a high-voltage (up to 700 V) power MOSFET with a lowvoltage analog and digital controller in a three-terminal device. The internal functions that have been integrated into the controller include the oscillator, start-up bias-current source,cycle-by-cycle current limit, pulse width modulator (PWM), thermal shutdown, auto-restart and gate driver. This paper analysis its internal circuitry basing on reverse engineering and computer simulation. And also give a typical application of Topswitch device.