脉冲宽度调制[1]（Pulse Width Modulation，缩写为PWM），简称脉宽调制，是利用微处理器的数字输出来对模拟电路进行控制的一种非常有效的技术，广泛应用在从测量、通信到功率控制与变换的许多领域中。脉冲宽度调制的一个优点是从处理器到被控系统信号都是数字形式的，无需进行数模转换-Pulse Width Modulation (PWM) [1] (Pulse Width Modulation, abbreviated as PWM) and Pulse Width Modulation for short, is the use of the microprocessor digital output to analog circuits to control a very effective technology, widely used in　measurement, communication to power control and transform in many areas. An advantage of pulse width modulation signal　the processor to be control system is digital form, without d/a conversion