IEICE Transactions on Electronics
Online ISSN : 1745-1353
Print ISSN : 0916-8524
Special Section on Analog Circuits and Their Application Technologies
Design and Experimental Verification of a 2.1nW 0.018mm2 Slope ADC-Based Supply Voltage Monitor for Biofuel-Cell-Powered Supply-Sensing Systems in 180-nm CMOS
Guowei CHENXujiaming CHENKiichi NIITSU
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2022 Volume E105.C Issue 10 Pages 565-570


This brief presents a slope analog-digital converter (ADC)-based supply voltage monitor (SVM) for biofuel-cell-powered supply-sensing systems operating in a supply voltage range of 0.18-0.35V. The proposed SVM is designed to utilize the output of energy harvester extracting power from biological reactions, realizing energy-autonomous sensor interfaces. A burst pulse generator uses a dynamic leakage suppression logic oscillator to generate a stable clock signal under the sub-threshold region for pulse counting. A slope-based voltage-to-time converter is employed to generate a pulse width proportional to the supply voltage with high linearity. The test chip of the proposed SVM is implemented in 180-nm CMOS technology with an active area of 0.018mm2. It consumes 2.1nW at 0.3V and achieves a conversion time of 117-673ms at 0.18-0.35V with a nonlinearity error of -5.5/+8.3mV, achieving an energy-efficient biosensing frontend.

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© 2022 The Institute of Electronics, Information and Communication Engineers
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