Design of a Low Power 10-b 8-MS/s Asynchronous SAR ADC with On-Chip Reference Voltage Generator

This paper presents an energy-efficient low power 10-b 8-MS/s asynchronous successive approximation register (SAR) analog-to-digital (ADC) converter. An inverted common-mode charge recovery technique is proposed to reduce the switching energy and to improve the linearity of the digital-to-analog con...

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Bibliographic Details
Main Authors: Khuram Shehzad, Deeksha Verma, Danial Khan, Qurat Ul Ain, Muhammad Basim, Sung Jin Kim, YoungGun Pu, Keum Cheol Hwang, Youngoo Yang, Kang-Yoon Lee
Format: Article
Language:English
Published: MDPI AG 2020-05-01
Series:Electronics
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Online Access:https://www.mdpi.com/2079-9292/9/5/872
Description
Summary:This paper presents an energy-efficient low power 10-b 8-MS/s asynchronous successive approximation register (SAR) analog-to-digital (ADC) converter. An inverted common-mode charge recovery technique is proposed to reduce the switching energy and to improve the linearity of the digital-to-analog converter (DAC). The proposed switching technique consumes only 149 CV<sub>REF</sub><sup>2</sup> switching energy for the 10-bit case. A rail-to-rail dynamic latch comparator is implemented with adaptive power control for better power efficiency. Additionally, to optimize the power consumption and performance of the logic part, a modified asynchronous type SAR control logic with digitally controllable delay cells is adopted. An on-chip reference voltage generator is also designed with an ADC core for practical use. The structure is realized using 55-nm complementary metal–oxide–semiconductor (CMOS) process technology. The proposed architecture achieves an effective number of bits (ENOB) of 9.56 bits and a signal-to-noise and distortion ratio (SNDR) level of 59.3 dB with a sampling rate of 8 MS/s at measurement level. The whole architecture consumes only 572 µW power when a power supply of 1 V is applied.
ISSN:2079-9292