改善开关瞬态非理想行为的A/D转换电路的设计

The Design of the A/D Converter Circuit for Improving the Transient non Ideal Behavior of the Switch

随着计算机技术和数字信号处理技术的飞速发展,在自动控制,测量和通信等领域中越来越普遍的情况就是把系统中输入进去的模拟信号转化成数字信号再进行相关的处理。但是,有的时候又有相关的操作要求系统在输出的时候要把已经处理过的数字信号转换成对应的模拟信号。这样,在模拟信号与数字信号之间,或在模拟信号与数字信号之间,需要有一个接口电路——A/D转换器或D/A转换器。在现今多媒体和通信技术的发展之中,得到大量应用的就是高精度A/D转换器。比如直接数字频率合成、高清晰度电视、无线通信系统信号发射等技术中都有高精度A/D转换器的应用实例。在转换的过程中要具有很好的动态性能指标这是高精度实用A/D转换所必须要求的,对电路设计的要求也偏高。由于要求增加转换精度和转换速率,误差也随之增大,这就给转换器的动态性能带来了巨大的影响。在这一系列的误差当中,影响最大的就是在开关的时候产生的瞬态非理想行为。本篇论文通过分析可能会影响到A/D转换器动态性能的此项误差和另外两项误差,根据分析提出了一种能够有效地改善开关瞬态非理想行为的新型电流源开关。在新型电流源开关电路的前提之下,我们提出了实用A/D转换电路的概念。

Along with the rapid development of computer technology and digital signal processing technology, the communication, measurement,automatic control and many other fields, to convert the input to the system of the analog signal to digital signal processing has been more and more prevalent. At the same time, and often require that the processing of digital signal is then converted to the corresponding analog signal, as the output of the system. Such, between analog signals and digital signals, or between analog signals and digital signals, need to have an interface circuit, d/a or a/d converter. The development of communication and multimedia technology high precision analog-to-digital converters to get a number of applications. Such as high definition television, direct digital frequency synthesis, wireless communication system signal emission and so on. High accuracy and practical analog-to-digital conversion requirement converter has good dynamic performance, also to the requirement of circuit design is on the high side. However, with the increase of conversion rate and conversion accuracy, dynamic performance is affected by the error more converter.One of the most important error is in the process of switch transient non-ideal behavior. In this paper, detailed analysis of the three kinds of error the effects on the dynamic performance da converter, and puts forward a new type of current source switch, effectively improve the switching transient non-ideal behavior. A new type of current source based on the proposed switching circuit, we put forward the concept of practical analog-to-digital conversion circuit.