Title
A 1.15 μW 200 kS/s 10-b Monotonic SAR ADC Using Dual On-Chip Calibrations and Accuracy Enhancement Techniques.
Abstract
Herein, we present an energy efficient successive-approximation-register (SAR) analog-to-digital converter (ADC) featuring on-chip dual calibration and various accuracy-enhancement techniques. The dual calibration technique is realized in an energy and area-efficient manner for comparator offset calibration (COC) and digital-to-analog converter (DAC) capacitor mismatch calibration. The calibration of common-mode (CM) dependent comparator offset is performed without using separate circuit blocks by reusing the DAC for generating calibration signals. The calibration of the DAC mismatch is efficiently performed by reusing the comparator for delay-based mismatch detection. For accuracy enhancement, we propose new circuit techniques for a comparator, a sampling switch, and a DAC capacitor. An improved dynamic latched comparator is proposed with kick-back suppression and CM dependent offset calibration. An accuracy-enhanced bootstrap sampling switch suppresses the leakage-induced error <180 V and the sampling error <150 V. The energy-efficient monotonic switching technique is effectively combined with thermometer coding, which reduces the settling error in the DAC. The ADC is realized using a 0.18 m complementary metal-oxide-semiconductor (CMOS) process in an area of 0.28 mm(2). At the sampling rate f(S) = 9 kS/s, the proposed ADC achieves a signal-to-noise and distortion ratio (SNDR) of 55.5 dB and a spurious-free dynamic range (SFDR) of 70.6 dB. The proposed dual calibration technique improves the SFDR by 12.7 dB. Consuming 1.15 W at f(S) = 200 kS/s, the ADC achieves an SNDR of 55.9 dB and an SFDR of 60.3 dB with a figure-of-merit of 11.4 fJ/conversion-step.
Year
DOI
Venue
2018
10.3390/s18103486
SENSORS
Keywords
Field
DocType
analog-to-digital converter,successive approximation register,comparator offset,capacitor mismatch calibration
Monotonic function,Electronic engineering,Successive approximation ADC,Engineering,Calibration
Journal
Volume
Issue
ISSN
18
10.0
1424-8220
Citations 
PageRank 
References 
1
0.43
13
Authors
6
Name
Order
Citations
PageRank
Jae-Hun Lee130.82
Dasom Park210.77
Woojin Cho310.43
Huu Nhan Phan410.43
Cong Luong Nguyen510.43
Jong-Wook Lee66611.45