A Versatile ± 25-A Shunt-Based Current Sensor With ± 0.25% Gain Error From − 40 ∘ C to 85 ∘ C

Journal article (2022)

Authors

Z. Tang Electronic Instrumentation - EEMCS
R.L. Brito Zamparette Electronic Instrumentation - EEMCS
Yoshikazu Furuta MIRISE Technologies Corporation
Tomohiro Nezuka MIRISE Technologies Corporation
K.A.A. Makinwa Microelectronics
Research Group
Electronic Instrumentation (EEMCS) (TU Delft)
Copyright: © 2022 Z. Tang, R.L. Brito Zamparette, Yoshikazu Furuta, Tomohiro Nezuka, K.A.A. Makinwa
DOI: https://doi.org/10.1109/JSSC.2022.3204520
Temperature compensation Current sensing Capacitively coupled amplifier (CCA) Delta-sigma () ADC Delta-sigma (ΔΣ) AD PCB trace Temperature coefficient (TC)
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Published Date

2022

Language

English

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Faculty

Electrical Engineering, Mathematics and Computer Science

Department

Microelectronics

Research Group

Electronic Instrumentation

Abstract

This article presents a versatile shunt-based current sensor for battery
management applications. It digitizes the current-induced voltage drop
across an external shunt resistor with the help of a 2
nd
-order delta-sigma (
ΔΣ

) ADC, whose summing node is implemented as a low-noise capacitively
coupled amplifier. To compensate for the shunt’s finite temperature
coefficient (TC), the TC of the ADC on-chip voltage reference can be
tuned. As a result, the sensor maintains high accuracy when used with
low-cost high TC shunts, such as PCB traces, as well as with more
expensive low TC shunts, such as metal-alloy resistors. Optimal gain
flatness over temperature is achieved by a two-current room-temperature
TC tuning scheme, which exploits the shunt’s self-heating at high
current levels. Fabricated in a standard 0.18-
μ
m CMOS process, the current sensor occupies 0.36 mm
2
and draws 265
μ
A from a 1.8-V supply. Over the industrial temperature range (
−
40
∘
C to 85
∘
C) and a
±
25-A current range, it achieves the state-of-the-art gain error (
±
0.25%) with both PCB (1.6 m
Ω
) and metal-alloy (2 m
Ω
) shunts. With these shunts, it achieves 5.3-mA/4.3-mA (rms) resolution in a 10-kHz bandwidth.