The ASDQ ASIC [Central Outer Tracker CDF upgrade application]

Abstract

The ASDQ ASIC provides eight channels of complete signal processing for the Central Outer Tracker (COT) being built for the CDF upgrade. The ASDQ has been fabricated using the well-characterized and radiation tolerant MAXIM SHPi analog bipolar process. It optimizes competing requirements of short measurement time (/spl ap/7 ns), good double pulse resolution (/spl sim/20 ns), low power (/spl ap/35 mW/ch) and low operational threshold (/spl sim/2-3 fC). It contains a low noise pseudo-differential preamplifier, ion tail compensation and multipole shaper, baseline restorer, comparator with an optional linear width encoded charge measurement and an on-chip calibration circuit. The design of the circuit is based on GARFIELD simulations of COT tracks and the response of a prototype chamber to cosmic rays and Fe/sup 55/ sources.