DocumentCode :
1122532
Title :
A time-to-digital-converter-based CMOS smart temperature sensor
Author :
Chen, Poki ; Chen, Chun-Chi ; Tsai, Chin-Chung ; Lu, Wen-Fu
Author_Institution :
Dept. of Electron. Eng., Nat. Taiwan Univ. of Sci. & Technol., Taipei, Taiwan
Volume :
40
Issue :
8
fYear :
2005
Firstpage :
1642
Lastpage :
1648
Abstract :
A time-to-digital-converter-based CMOS smart temperature sensor without a voltage/current analog-to-digital converter (ADC) or bandgap reference is proposed for high-accuracy portable applications. Conventional smart temperature sensors rely on voltage/current ADCs for digital output code conversion. For the purpose of cost reduction and power savings, the proposed smart temperature sensor first generates a pulse with a width proportional to the measured temperature. Then, a cyclic time-to-digital converter is utilized to convert the pulse into a corresponding digital code. The test chips have an extremely small area of 0.175 mm2 and were fabricated in the TSMC CMOS 0.35-μm 2P4M process. Due to the excellent linearity of the digital output, the achieved measurement error is merely -0.7∼+0.9°C after two point calibration, but without any curvature correction or dynamic offset cancellation. The effective resolution is better than 0.16°C, and the power consumption is under 10 μW at a sample rate of 2 samples/s.
Keywords :
CMOS integrated circuits; analogue-digital conversion; intelligent sensors; pulse generators; temperature sensors; 0.35 micron; CMOS integrated circuits; CMOS smart temperature sensor; cyclic time-to-digital-converter; intelligent sensor; pulse conversion; pulse generators; Analog-digital conversion; Costs; Photonic band gap; Power generation; Pulse generation; Pulse measurements; Space vector pulse width modulation; Temperature measurement; Temperature sensors; Voltage; Delay line; intelligent sensor; temperature sensor; time-to-digital converter (TDC);
fLanguage :
English
Journal_Title :
Solid-State Circuits, IEEE Journal of
Publisher :
ieee
ISSN :
0018-9200
Type :
jour
DOI :
10.1109/JSSC.2005.852041
Filename :
1487607
Link To Document :
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