A 1.1 μW CMOS smart temperature sensor with an inaccuracy of ±0.2 °C (3σ) for clinical temperature monitoring

Man Kay Law, Sanfeng Lu, Tao Wu, Amine Bermak, Pui In Mak, Rui P. Martins

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

In this paper, an ultra-low power, high accuracy CMOS smart temperature sensor customized for clinical temperature monitoring based on substrate p-n-p bipolar junction transistors (BJTs) is presented. A power efficient analog front end with a sensing-range customized multi-ratio pregain stage is proposed to effectively utilize the input range of the incremental analog-to-digital converter to relax the conversion speed and resolution requirement. A block-based data weighted averaging technique is also proposed to achieve highly accurate pre-gain ratios while significantly reducing the implementation complexity. The complete temperature sensor is implemented in a standard 0.18 μm CMOS process occupying an active area of 0.198 mm. Measurement results from 20 test chips show that an inaccuracy of ±0.2 °C (3σ) is achieved from 25 °C to 45 °C after one-point calibration. The average power consumption is 1.1 μW at a conversion speed of 2 Sa/s.

Original languageEnglish
Article number6411595
Pages (from-to)2272-2281
Number of pages10
JournalIEEE Sensors Journal
Volume16
Issue number8
DOIs
Publication statusPublished - 15 Apr 2016

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Keywords

  • Block-based data weighted averaging (BDWA)
  • High accuracy
  • Incremental analog-to-digital converter (I-ADC)
  • Multi-ratio pre-gain
  • Smart temperature sensor
  • Ultra-low power

ASJC Scopus subject areas

  • Instrumentation
  • Electrical and Electronic Engineering

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