Print Email Facebook Twitter A 2.5-μW Beyond-the-Rails Current Sensor With a Tunable Voltage Reference and ±0.6% Gain Error From −40 ◦C to +85 ◦C Title A 2.5-μW Beyond-the-Rails Current Sensor With a Tunable Voltage Reference and ±0.6% Gain Error From −40 ◦C to +85 ◦C Author Brito Zamparette, R.L. (TU Delft Electronic Instrumentation) Makinwa, K.A.A. (TU Delft Microelectronics) Department Microelectronics Date 2022 Abstract This letter presents a low-power, fully integrated current sensor for Coulomb-counting. It employs a hybrid delta–sigma modulator ( ΔΣM ) with an FIR-DAC to digitize the voltage drop across a shunt. The modulator’s first stage consists of a capacitively coupled chopper amplifier, which enables a beyond-the-rails (−0.3 to 5 V) input common-mode voltage range from a 1.8-V supply. A tunable voltage reference is used to accurately compensate for the large temperature coefficient ( ∼3500 ppm/°C) of low-cost metal shunts. With a 20- mΩ on-chip shunt, ±2 A currents can be digitized with 0.35% gain error from −40°C to 85°C, after a 1-point trim. With a 3- mΩ PCB trace, currents up to ±15 A can be digitized with 0.6% gain error over the same temperature range. Fabricated in a standard 0.18- μm CMOS process, the sensor occupies 1.6 mm2 and consumes 2.5 μW , which is 3× less than the state of the art. It also achieves competitive energy efficiency, with a figure of merit (FoM) of 149 dB. Subject coulombcountingcurrent sensorFIR-DACFully-integratedhigh-sidehybrid delta-sigma modulatoron-chip shunt resistorPCB trace shunt resistor To reference this document use: http://resolver.tudelft.nl/uuid:78cf99d5-2ed0-4165-a27b-5243858da641 DOI https://doi.org/10.1109/LSSC.2022.3219214 Embargo date 2023-05-03 ISSN 2573-9603 Source IEEE Solid State Circuits Letters, 5, 264 - 267 Bibliographical note Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2022 R.L. Brito Zamparette, K.A.A. Makinwa Files PDF A_2.5_W_Beyond_the_Rails_ ... o_85_C.pdf 4.05 MB Close viewer /islandora/object/uuid:78cf99d5-2ed0-4165-a27b-5243858da641/datastream/OBJ/view