Title :
Temperature-to-frequency converter consisting of subthreshold mosfet circuits for smart temperature-sensor LSIs
Author :
Ueno, Ken ; Asai, Tetsuya ; Amemiya, Yoshihito
Author_Institution :
Dept. of Electr. Eng., Hokkaido Univ., Sapporo, Japan
Abstract :
An ultra-low-power temperature sensor circuit has been developed using a 0.35-mum standard CMOS process. The circuit consists of a proportional-to-absolute-temperature (PTAT) current generator and a frequency-locked loop, and generates a PTAT clock frequency. The PTAT current generator is the key component of the sensor and was constructed by using the characteristics of a MOSFET in the subthreshold region. Theoretical analyses and experimental results showed that the circuit can be used as a temperature sensor with ultra-low-power consumption of 10 muW or less. The accuracy of the sensor output was within plusmn1.8degC in a temperature range from 10degC to 80degC. Our sensor would be suitable for use in subthreshold-operated, power-aware LSIs.
Keywords :
CMOS analogue integrated circuits; frequency convertors; frequency locked loops; intelligent sensors; large scale integration; low-power electronics; temperature sensors; CMOS process; PTAT clock frequency; frequency-locked loop; power 10 muW; proportional-to-absolute-temperature current generator; size 0.35 mum; smart temperature-sensor LSIS; subthreshold MOSFET circuits; temperature 10 degC to 80 degC; temperature-to-frequency converter; ultra-low-power temperature sensor circuit; CMOS process; Character generation; Clocks; Frequency locked loops; Intelligent sensors; MOSFET circuits; Sensor phenomena and characterization; Standards development; Temperature distribution; Temperature sensors; CMOS; Frequency-locked loop; PTAT; Power-aware LSI; Subthreshold current; Temperature sensor; Ultra-low power; Weak inversion;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems Conference, 2009. TRANSDUCERS 2009. International
Conference_Location :
Denver, CO
Print_ISBN :
978-1-4244-4190-7
Electronic_ISBN :
978-1-4244-4193-8
DOI :
10.1109/SENSOR.2009.5285436
