Title :
A Compact Temperature Sensor at 1.8µA per Hz Conversion Rate and 1.1 °C Accuracy for SOCs
Author :
Sen, Subhajit ; Babitch, Dan ; Dubash, Noshir
Author_Institution :
DAIICT, Gandhinagar, India
Abstract :
A compact (0.1 mm2 area) temperature-recording system that is suitable for easy integration into an SOC is described. It includes a PTAT sensor, a pre-amplifier, and a first-order sigma-delta modulator based ADC all operating at 1.2V supply. The switched-capacitor pre-amplifier uses an auto-zeroing scheme based upon capacitive reset to avoid the need for shorting the op-amp outputs and inputs during reset. Errors due to transistor leakage are eliminated by selective use of thick-oxide transistors in the design. Another contribution of the paper is to illustrate a scheme that uses two reference voltages in the sigma-delta modulator ADC corresponding to the minimum and maximum temperatures measured to improve its effective resolution.
Keywords :
capacitor switching; operational amplifiers; preamplifiers; sigma-delta modulation; system-on-chip; temperature sensors; ADC; Hz conversion rate; PTAT sensor; SOC; compact temperature sensor; current 1.8 muA; first- order sigma-delta modulator; op-amp outputs; switched-capacitor preamplifier; temperature 1.1 degC; temperature-recording system; thick-oxide transistors; transistor leakage; voltage 1.2 V; Modulation; Sigma delta modulation; System-on-a-chip; Temperature distribution; Temperature measurement; Temperature sensors; Transistors; MOSFET; PTAT (proportional to absolute temperature); auto-zeroing; sigma-delta modulator; sub-threshold leakage current; switched-capacitor; system-on-chip (SOC);
Conference_Titel :
VLSI Design (VLSID), 2012 25th International Conference on
Conference_Location :
Hyderabad
Print_ISBN :
978-1-4673-0438-2
DOI :
10.1109/VLSID.2012.67
