一、前言线性电路,尤其是运算放大器,要求管子的耐压高(一般大于30V),还要求小电流工作有较大的电流放大系数,同时,电路中所用管子种类较多:有NPN 管、PNP 管(包括纵向PNP 和横向PNP ),还有MOS 管等等。由于这些特点,用PN 结隔离工艺做运算放大器,从工艺的选择到工艺本身都有一些需要解决的特殊问题。我们学习国内外的经验,经过试验摸索,逐步解决了一些问题。用PN 结隔离工艺生产了运算放大器FD42(相当于国外的μA741),主要技术指标均达到设计要求,产品经过筛选已交整机使用,性能良好,并做过抗辐照试验。FD42与国外近期产品μA741 I. INTRODUCTION Linear circuits, especially operational amplifiers, require tubes with high withstand voltage (typically greater than 30V) and also require large current amplification factors for low-current operation. At the same time, there are many types of tubes used in the circuit: NPN tubes, PNP tube (including vertical PNP and lateral PNP), there are MOS tubes and so on. Because of these characteristics, using the PN junction isolation process as an operational amplifier, from the process of choice to the process itself has some special problems to be solved. We study the experience both at home and abroad, after trial and error, and gradually solve some problems. Using PN junction isolation process to produce the operational amplifier FD42 (equivalent to the overseas μA741), the main technical indicators have reached the design requirements, the product has been selected by the machine to use, good performance, and anti-radiation tests done. FD42 and recent foreign products μA741