Title :
Subthreshold Operation of a Monolithically Integrated Strained-Si Current Mirror at Low Temperatures
Author :
Fobelets, K. ; Gaspari, V. ; Ding, P.W.
Author_Institution :
Dept. of Electr. Eng., Imperial Coll. London
Abstract :
The dc operation of a simple current mirror built with two monolithically integrated strained-Si (s-Si) MOSFETs operating in the subthreshold region is studied as a function of temperature. At room temperature, the log-log current relationship is linear over 4 dec. The consumed power is approximately 100 muW at 300 K but only 1 nW at 160 K. The cost of this reduction in power is a reduced linear log-log current range. Reducing the temperature further increases the threshold voltage, obstructing operation below 160 K. A comparison is made with the Si control circuit, highlighting the improved linearity and the threshold voltage stability in the s-Si circuit. The estimated cutoff frequency of the subthreshold strained-Si current mirror at 300 K is 50 MHz, compared to 10 kHz for the Si MOSFETs
Keywords :
MOS integrated circuits; cryogenic electronics; current mirrors; elemental semiconductors; monolithic integrated circuits; silicon; 10 kHz; 160 K; 300 K; 50 MHz; Si; cryogenic operation; log-log current relationship; monolithically integrated current mirror; strained-Si MOSFET; subthreshold region; threshold voltage stability; Circuit stability; Costs; Frequency estimation; Linearity; MOSFETs; Mirrors; Silicon; Temperature control; Threshold voltage; Voltage control; Cryogenic operation; current mirror; strained-Si (s-Si) MOSFET;
Journal_Title :
Circuits and Systems II: Express Briefs, IEEE Transactions on
DOI :
10.1109/TCSII.2006.882365
