A Novel Low Distortion Switch Used in A/D Converter for Directly Sampling Bipolar Voltage Signals
In order to directly and accurately sample a bipolar voltage signal into a unipolar supply A/D converter with normal CMOS technology, a novel low distortion switch is proposed. This novel switch is composed of only four PMOS transistors, one capacitor and one normal switch. It can directly sample a bipolar signal without a conventional used voltage level shift circuit and makes the circuit free of noise, distortion and temperature characteristics problems that are caused by voltage level shift circuit. This switch is one type of high linear bootstrapped switches, of which the source to gate voltage is kept to a constant value to reduce nonlinearity. A sample/hold circuit with this novel switch is implemented in a 12-bit ΣΔ A/D converter with a standard 0.5μm mixed mode CMOS process. By simulation, this sample/hold circuit achieves a 120dB SFDR when sampling a 1V peak-to-peak, 156 KHz bipolar signal under 10MS/s sampling rate.
Cui MAO Le-nian HE Xiao-lang YAN
Institute of VLSI design Department of Electronic Engineering Zhejiang University Hangzhou, Zhejiang, China
国际会议
2006 International Conference on Communications,Circuits and Systems(第四届国际通信、电路与系统学术会议)
广西桂林
英文
2230-2234
2006-06-25（万方平台首次上网日期，不代表论文的发表时间）