Title :
A sub-1V BJT-based CMOS temperature sensor from −55 °C to 125 °C
Author :
Wang, Bo ; Law, Man Kay ; Tang, Fang ; Bermak, Amine
Author_Institution :
ECE Dept., Hong Kong Univ. of Sci. & Technol., Kowloon, China
Abstract :
In this paper, a smart temperature sensor working at a supply voltage as low as 0.9V over the full military temperature range is presented. Low voltage operation is achieved by biasing the front-end BJT pairs with different emitter currents for two different sensing ranges, from -55°C to 30°C and from 20°C to 125°C, respectively. A second-order inverter-based ΣΔADC with dynamic element matching (DEM) and input signal chopping to control the conversion error to within 0:2°C is used for digital readout. Front-end bias currents are selected during the design stage to minimize the induced sensing error. The proposed sensor is implemented using the TSMC 0.18μm 1P6M process. Simulation result shows that a +1°C=-0:1°C sensing error using one-point calibration can be achieved from -55°C to 125°C. At a sampling speed of 20 samples/s, the sensor consumes 3.4μA and 4.7μA in the low temperature range and the high temperature range, respectively.
Keywords :
CMOS integrated circuits; bipolar transistors; detector circuits; readout electronics; sigma-delta modulation; temperature sensors; BJT based CMOS temperature sensor; analog-digital converter; conversion error control; digital readout; dynamic element matching; input signal chopping; second order inverter based sigma-delta ADC; temperature -55 C to 125 C; CMOS integrated circuits; Calibration; Inverters; Noise; Temperature distribution; Temperature sensors;
Conference_Titel :
Circuits and Systems (ISCAS), 2012 IEEE International Symposium on
Conference_Location :
Seoul
Print_ISBN :
978-1-4673-0218-0
DOI :
10.1109/ISCAS.2012.6271980