基于0.35μm工艺的Delta-Sigma ADC实现

Implementation of Delta-Sigma ADC based on 0.35μm PDK

在众多音频模数转换器中,Delta-Sigma是一种很流行的结构,其内部采用位A/D转换器,因此其对模拟信号处理部分的电路要求远远小于对整个电路的精度要求。在局部模块的精度较低时也能正常工作。Delta-Sigma A/D主要应用于中低带宽的音频信号,讨论采用AMS 0.35μm PDK实现模数转换电路。该电路核心部分采用Folded-Cascode结构的差动放大器,仿真结果表明该结构的电路能较稳定地工作于低频段。

Delta-Sigma modulation has become quite popular for achieving high resolution.One significant advantage of the method is that analog signals are eonverted by using only 1-hit ADC,and analog signal processing circuits have a precision that is usually much less than the resolution of the overall converter.This paper presents a structure based on Folded- Cascode Op-amp,the simulation results prove that it works well at low frequency by using the 0.35μm PDK.