A 12-b Asynchronous SAR Type ADC for Bio Signal Detection

• Published in: Journal of semiconductor technology and science Vol. 13; no. 2; pp. 108 - 113
• Main Authors: Lim, Shin-Il, Kim, Jin Woo, Yoon, Kwang-Sub, Lee, Sangmin
• Format: Journal Article
• Language: English
• Published: 대한전자공학회 01.04.2013
• Subjects: 전기공학; SAR type ADC; asynchronous control; biomedical; splitcapacitor array
• ISSN: 1598-1657; 2233-4866
• DOI: 10.5573/JSTS.2013.13.2.108

This paper describes a low powerasynchronous successive approximation register(SAR) type 12b analog-to-digital converter (ADC) forbiomedical applications in a 0.35 μm CMOStechnology. The digital-to-analog converter (DAC)uses a capacitive split-arrays consisting of 6-b mainarray, an attenuation capacitor C and a 5-b sub arrayfor low power consumption and small die area. Moreover, splitting the MSB capacitor into subcapacitorsand an asynchronous SAR reduce powerconsumption. The measurement results show that theproposed ADC achieved the SNDR of 68.32 dB, theSFDR of 79 dB, and the ENOB (effective number ofbits) of 11.05 bits. The measured INL and DNL were1.9LSB and 1.5LSB, respectively. The powerconsumption including all the digital circuits is 6.7μW at the sampling frequency of 100 KHz under 3.3V supply voltage and the FoM (figure of merit) is 49fJ/conversion-step. KCI Citation Count: 6