Print Email Facebook Twitter A 6.6-μW Wheatstone-Bridge Temperature Sensor for Biomedical Applications Title A 6.6-μW Wheatstone-Bridge Temperature Sensor for Biomedical Applications Author Pan, S. (TU Delft Electronic Instrumentation) Makinwa, K.A.A. (TU Delft Microelectronics) Department Microelectronics Date 2020 Abstract This letter presents a compact, energy-efficient, and low-power Wheatstone-bridge temperature sensor for biomedical applications. To maximize sensitivity and reduce power dissipation, the sensor employs a high-resistance (600 kΩ ) bridge that consists of resistors with positive (silicided-poly) and negative ( n -poly) temperature coefficients. Resistor spread is then mitigated by trimming the n -poly arms with a 12-bit DAC, which consists of a 5-bit series DAC whose LSB is trimmed by a 7-bit PWM generator. The bridge is readout by a second-order delta-sigma modulator, which dynamically balances the bridge by tuning the resistance of the silicided-poly arms via a 1-bit series DAC. As a result, the modulator's bitstream average is an accurate and near-linear function of temperature, which does not require further correction in the digital domain. Fabricated in a 180-nm CMOS technology, the sensor occupies 0.12 mm2. After a 1-point trim, it achieves +0.2 °C/-0.1 °C ( 3σ ) inaccuracy in a ±10 °C range around body temperature (37.5 °C). It consumes 6.6 μW from a 1.6-V supply, and achieves 200- μK resolution in a 40-ms conversion time, which corresponds to a state-of-the-art resolution FoM of 11 fJ K2. Duty cycling the sensor results in even lower average power: 700 nW at 10 conversions/s. Subject Biomedicalenergy efficiencylow powertemperature sensortrimming To reference this document use: http://resolver.tudelft.nl/uuid:7a407e68-bbb0-4fe7-9b37-138e4724d72e DOI https://doi.org/10.1109/LSSC.2020.3019078 Embargo date 2022-03-25 ISSN 2573-9603 Source IEEE Solid State Circuits Letters, 3, 334-337 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 © 2020 S. Pan, K.A.A. Makinwa Files PDF 09174947.pdf 1.78 MB Close viewer /islandora/object/uuid:7a407e68-bbb0-4fe7-9b37-138e4724d72e/datastream/OBJ/view