CACD是在五十年代中后期开始出现的。随着高速数字计算机的发展,在六十年代研制出许多网络和电路分析程序。在给定网络或电路的拓扑结构与元件特性的情况下,它们能对网络或电路进行直流、交流和瞬态等分析。这种分析过程就象用仪器对电路进行测量一样,所以又称为电路模拟,对这些分析程序又称为电路模拟器。进入七十年代以来,随着集成电路技术的迅速发展,集成电路的规模愈来愈大,功能愈来愈强,电路愈来愈复杂。从而对CACD CACD began in the late fifties. With the development of high-speed digital computers, many network and circuit analysis programs were developed in the 1960s. Given the topology and component characteristics of a network or circuit, they provide DC, AC, and transient analysis of the network or circuit. This analysis process is like measuring the circuit with the instrument, so it is also called circuit simulation. For these analysis programs, it is also called circuit simulator. Since entering seventies, with the rapid development of integrated circuit technology, the scale of integrated circuits is getting bigger and bigger, the functions are getting stronger and stronger, and the circuits are getting more complicated. Thus to CACD