Speaker
Description
A programmable low-power, low-noise readout circuit for Cadmium Zinc Telluride (CdZnTe or CZT) detectors is presented. CdZnTe detectors encompass a wide range of applications such as medical imaging and astrophysics. The front-end comprises a charge-sensitive amplifier (CSA), a programmable reset network with dark current compensation capability, a fifth-order semi-Gaussian filter with pole-zero cancellation, a comparator, and a serial interface to communicate with an external microcontroller. Utilizing the programmability of the reset-network, the CSA can provide 256 different discharge time-constants, ranging from 60n to 600u seconds, making the readout suitable for a wide range of event-rates. The application-specific integrated circuit (ASIC) is designed and simulated in a 0.35-um 3.3V C35 CMOS process of Austria Micro-Systems. CSA only consumes 260u watts and operates with dual-supply.
