DocumentCode :
1123159
Title :
A floating-gate comparator with automatic offset adaptation for 10-bit data conversion
Author :
Wong, Yanyi Liu ; Cohen, Marc H. ; Abshire, Pamela A.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Maryland, College Park, MD, USA
Volume :
52
Issue :
7
fYear :
2005
fDate :
7/1/2005 12:00:00 AM
Firstpage :
1316
Lastpage :
1326
Abstract :
We present a novel voltage comparator that uses nonvolatile floating-gate charge storage for either offset ing or automatic programming of a desired offset. We exploit the negative feedback mechanism of pFET hot-electron injection to achieve fully automatic offset cancellation. The adaptation guarantees an input offset less than the input-referred noise level regardless of initial device offset for a typical 8.3% observed injection mismatch. In addition, we demonstrate the ability to accurately program a desired offset. The design has been fabricated in a commercially available 0.35-μm process. Experimental results confirm the ability to reduce the variance of the initial offset by two orders of magnitude and to accurately program a desired offset with maximum observed deviation 728 μV and typical deviation 109 μV. The mean offset is reduced by a factor of 416 relative to fabricated chips directly from the foundry and by a factor of 202 relative to UV-irradiated chips. Adaptation is fast, with settling time typically under 50 ms and scaling inversely with the exponential of the injection voltage. We achieve controlled injection to accurately program the input offset to voltages uniformly distributed from -1 to 1 V. The comparator exhibits a 5 ns propagation delay and consumes 270 μW.
Keywords :
comparators (circuits); data conversion; feedback amplifiers; hot carriers; operational amplifiers; -1 V; 0.35 micron; 10 bit; 270 muW; CMOS integrated circuits; UV-irradiated chips; analog-digital conversion; automatic offset adaptation; automatic offset cancellation; automatic programming; data conversion; hot-electron injection; nonvolatile floating-gate charge storage; pFET; propagation delay; very large-scale integration; voltage comparator; Calibration; Circuits; Clocks; Data conversion; Laboratories; Nonvolatile memory; Physics; Storage automation; Switches; Voltage; Adaptive systems; CMOS integrated circuits; analog memories; analog–digital conversion; calibration; comparators; floating gate; hot carriers; offset cancellation; very large-scale integration (VLSI);
fLanguage :
English
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
Publisher :
ieee
ISSN :
1549-8328
Type :
jour
DOI :
10.1109/TCSI.2005.851389
Filename :
1487660
Link To Document :
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