在各类测量、控制系统,特别是计算机控制系统中,经常需要在两个电气上互相隔离的电路之间线性地传输模拟信号。在这种情况下,通常应用调制式数据放大器。本文介绍一种使用半导体光耦合器件的隔离电路,它具有良好的线性度,并且在绝缘性能、可靠性、成本、体积和重量上为调制式数据放大器所不及。常用的半导体光耦合器是一个四端元件,其输出端(光敏管)工作在反向偏置态(图1)。当在输入端(发光二极管)通入正向电 In various types of measurement and control systems, especially computer control systems, it is often necessary to transmit analog signals linearly between two electrically isolated circuits. In this case, a modulated data amplifier is usually used. This article describes an isolated circuit using semiconductor optical coupling devices that has good linearity and is out of range for modulated data amplifiers in terms of insulation, reliability, cost, size and weight. Commonly used semiconductor optocoupler is a four-terminal device, the output (phototube) work in reverse bias state (Figure 1). When the input (light-emitting diode) into the positive electricity