Title
A Sub-1 V Capacitively Biased BJT-Based Temperature Sensor With an Inaccuracy of ± 0.15 ∘ C (3 σ ) From − 55 ∘ C to 125 ∘ C
Author
Tang, Z. (TU Delft Electronic Instrumentation; Vango Technologies Inc., Hangzhou)
Pan, S. (TU Delft Electronic Instrumentation; Tsinghua University)
Grubor, M. (TU Delft Electronic Instrumentation; Analog Devices)
Makinwa, K.A.A. (TU Delft Microelectronics)
Department
Microelectronics
Date
2023
Abstract
This article presents a sub-1 V bipolar junction transistor (BJT)-based temperature sensor that achieves both high accuracy and high energy efficiency. To avoid the extra headroom required by conventional current sources, the sensor’s diode-connected BJTs are biased by precharging sampling capacitors to the supply voltage and then discharging them through the BJTs. This capacitive biasing technique requires little headroom ( ∼ 150 mV), and simultaneously samples the BJTs’ base–emitter voltages. The latter are then applied to a switched-capacitor (SC) ΔΣ ADC to generate a digital representation of temperature. For robust sub-1 V operation and high energy efficiency, the ADC employs auto-zeroed inverter-based integrators. Fabricated in a standard 0.18- μ m CMOS process, the sensor occupies 0.25 mm 2 and consumes 810 nW from a 0.95-V supply at room temperature. It achieves an inaccuracy of ± 0.15 ∘ C (3 σ ) from − 55 ∘ C to 125 ∘ C after a 1-point trim, which is at par with the state-of-the-art. It also achieves a resolution figure of merit (FoM) of 0.34 pJ ⋅ K 2 , which is more than 6 × lower than that of state-of-the-art BJT-based sensors with similar accuracy.
Subject
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capacitively biased bipolar junction transistor (BJT)
Capacitors
Energy efficiency
inverter-based amplifier
Mathematics
Switches
Switching circuits
temperature sensor
Temperature sensors
temperature to digital converter
Voltage
To reference this document use:
http://resolver.tudelft.nl/uuid:658e90b7-5846-4875-a723-9e947860c5a2
DOI
https://doi.org/10.1109/JSSC.2023.3308554
Embargo date
2024-05-28
ISSN
0018-9200
Source
IEEE Journal of Solid State Circuits, 58 (12), 3433-3441
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
© 2023 Z. Tang, S. Pan, M. Grubor, K.A.A. Makinwa