A CMOS Thermistor- Embedded Continuous-Time Delta-Sigma Temperature Sensor With a Resolution FoM of 0.65 pJ°C2
Journal
IEEE Journal of Solid-State Circuits
Journal Volume
50
Journal Issue
11
Pages
18860-18871
Date Issued
2015
Author(s)
Abstract
In a smart temperature sensor system, two individual building blocks, a sensing front-end and an analog-to-digital converter, are cascaded to implement the temperature-to-digital conversion. In this work, a thermistor-embedded continuous-time delta-sigma modulator (CTDSM), which merges these two building blocks into one, is proposed for a hardware- and energy-efficient temperature acquisition. The thermistor-based sensing front-end is reused in a 2nd-order 1 bit CTDSM to attain a high-resolution, low hardware complexity, and energy-efficient temperature sensing. Furthermore, a resistor-ladder with a switch on-resistance compensation scheme is proposed to implement the trimming circuit. Over a range of -45 °C ∼ 125°C, the proposed smart temperature sensor consumes 64.5μW from 1.5 V supply voltage and achieves a resolution around 0.01 °C rms (1σ) temperature resolution with a single conversion time of 100 μs. The corresponding resolution FoM is 0.65 pJ °C2. With 1-point trimming, this design achieves ±1°C temperature inaccuracy; this inaccuracy can be further improved to ±0.4°C with additional batch calibration. © 1966-2012 IEEE.
Subjects
Modulation; Resistance; Resistors; Switches; Temperature sensors; Thermistors
SDGs
Other Subjects
Analog to digital conversion; Continuous time systems; Delta sigma modulation; Energy efficiency; Hardware; Modulators; Semiconductor junctions; Thermistors; Trimming; Analog to digital converters; Compensation scheme; Delta sigma modulator; Digital conversion; Hardware complexity; Smart temperature sensors; Temperature resolution; Temperature sensing; Temperature sensors
Type
journal article