一、引言模数(A/D)转换器在数字仪器和控制系统中都起着重要的作用。它担负着把工程技术中各种模拟信号变换为满足一定关系的数字信号的工作。随着电子器件集成化的发展,A/D转换器已得到广泛应用,不仅应用于测量和自动技术,而且通过传感器应用于压力、速度、流量、温度等方面的测量。脉冲调宽是A/D转换器中的一种形式。它和计数器、可逆计数器或电子计算机联合使用,可实现各种电量和非电量参数的测量 I. Introduction Analog-to-digital (A / D) converters play an important role in both digital instrumentation and control systems. It is responsible for the engineering and technical transformation of a variety of analog signals to meet a certain relationship between the digital signal. With the development of integrated electronic devices, A / D converters have been widely used not only in measurement and automation technologies, but also in sensors for pressure, speed, flow, temperature and other measurements. Pulse width modulation is a form of A / D converter. It is used in conjunction with counters, reversing counters, or electronic computers to enable the measurement of various power and non-power parameters