一种可变基准的两步比较式A／D转换器

本论文提出了一种以模拟开关来改变基准电压，以流水线工作模式运行的两步比较Ａ／Ｄ新方案，革除了闪烁式需用大量高性能比较器和一般并－串式需要高速Ａ／Ｄ和高增益、高压摆率放大器的不足。这种改变基准电压Ａ／Ｄ转换器（ＣＲ ＡＤＣ）具有高的采样速率，并在获得相同性能和技术指标的前提下，应用的器件数降至最少。论文对此方案的原理、工作过程作了详细介绍。给出了性能测试方法和数值。

A Changeable Reference Two-step Analog-to-digital Converter

A novel technique of pipelined two- step analog-to-digital convertion, which is based on changing reference voltage by controlled analog switches, is introduced in the pa-per. This changeable reference analog-to-digital converter (CR ADC)has a higher sampling rate, and the number of devices on the same condition of performance and specifications is the least. While the conventional two-step convertion techniques require highspeed digital-to-analog converter (DAC) and operational amplifiers with highgain,largeslew rate the flash tech-nique requires a lot of high performance comparators. In this paper, the pinciple and operating course of the novel technique are discribed in detail. The circuit structure and parameter of a 8 -b, 10M-Sample/s CR ADC are showed. The testing methed of CR ADC is discussed, and its characteristic is given at the end of the paper.