Affiliation:
1. Zhongshan Institute, University of Electronic Science and Technology of China, Zhongshan 528402, China
2. School of Microelectronics, South China University of Technology, Guangzhou 510640, China
Abstract
A low-power SAR ADC with capacitor-splitting energy-efficient switching scheme is proposed for wearable biosensor applications. Based on capacitor-splitting, additional reference voltage Vcm, and common-mode techniques, the proposed switching scheme achieves 93.76% less switching energy compared to the conventional scheme with common-mode voltage shift in one LSB. With the switching scheme, the proposed SAR ADC can lower the dependency on the accuracy of Vcm and the complexity of digital control logic and DAC driver circuits. Furthermore, the SAR ADC employs low-noise and low-power dynamic comparators utilizing multi-clock control, low sampling error sampling switches based on the bootstrap technique, and dynamic SAR logic. The simulation results demonstrate that the ADC achieves a 61.77 dB SNDR and a 78.06 dB SFDR and consumes 4.45 μW of power in a 180 nm process with a 1 V power supply, a full-swing input signal frequency of 93.33 kHz, and a sampling rate of 200 kS/s.
Funder
National Natural Science Foundation of China
Key Field Project of Colleges and Universities in Guangdong Province
Key Project of Social Welfare and Basic Research Project in Zhongshan City
Construction Project of Professional Quality Engineering in 2020
Construction Project of Professional Quality Engineering in 2021
Subject
Electrical and Electronic Engineering,Mechanical Engineering,Control and Systems Engineering