摘要
本文提出一种低功耗、高精度、低复杂度的SAR ADC(逐次逼近模数转换器)的DAC电容阵列开关切换方案。每一个电容只连接了两种参考电平,因此降低了逐次逼近逻辑电路和电容驱动电路的复杂度。在前两次开关切换过程中不需要消耗能量,并且是单边切换,有效的降低了开关能量的消耗。DAC电容阵列分为完全相同的两部分,即MSB电容阵列和主电容阵列。MSB电容采用分裂二进制电容阵列的形式,并且采用C-2C电容结构代替LSB单位电容C,减少电容失配,提高ADC的线性度。与传统的二进制加权DAC结构相比,该方案减少了75%的DAC电容阵列面积,降低了96.90%开关能耗。
In this letter,a more energy-efficient,area-efficient,high accuracy and low complexity DAC capacitor array switching scheme is proposed for SAR ADC.In each switching,only two reference voltages participate in the switching scheme,which reduces the complexity of digital control logic and capacitor drive circuit.In the first two switching,there is no need to consume energy,and it is one-side switching,which effectively reduces the switching energy consumption.The DAC capacitor array is divided into the identical two parts,the MSB capacitor array and the Main capacitor array.The MSB capacitor is in the form of a split binary capacitor array,and the C-2C capacitor structure replaces the LSB unit capacitor C to reduce the capacitor mismatch and improve the linearity of the ADC.Compared with the traditional binary weighted DAC structure,this method can reduce the area by 75%and reduce the switching energy consumption by 96.90%.
出处
《中国集成电路》
2020年第12期59-62,共4页
China lntegrated Circuit
关键词
SAR
ADC
分裂电容
开关切换
低功耗
高精度
低复杂度
SAR ADC
Split capacitor
Switching
Low power consumption
High precision
Low complexity
