A CMOS Time to Digital Converter IC with 2 Level Analog CAM

Eric J. Gerds, University of Pennsylvania
Jan Van der Spiegel, University of Pennsylvania
Rick Van Berg, University of Pennsylvania
Hugh H. Williams, University of Pennsylvania
L. Callewaert, Kath. University of Leuven
W. Eyckmans, Kath. University of Leuven
Willy Sansen, Kath. University of Leuven

Article comments

Copyright 1994 IEEE. Reprinted from IEEE Journal of Solid State Circuits, Volume 29, Issue 9, September 1994, pages 1068-1076.
Publisher URL: http://dx.doi.org/10.1109/4.309902

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Abstract

A time to charge converter IC with an analog memory unit (TCCAMU) has been designed and fabricated in HP's CMOS 1.2-µm n-well process. The TCCAMU is an event driven system designed for front end data acquisition in high energy physics experiments. The chip includes a time to charge converter, analog Level 1 and Level 2 associative memories for input pipelining and data filtering, and an A/D converter. The intervals measured and digitized range from 8-24 ns. Testing of the fabricated chip resulted in an LSB width of 107 ps, a typical differential nonlinearity of < 35 ps, and a typical integral nonlinearity of < 200 ps. The average power dissipation is 8.28 mW per channel. By counting the reference clock, a time resolution of 107 ps over ~ 1 s range could be realized.