Design of a Multi-Channel Low-Noise Readout ASIC for CdZnTe-Based X-Ray and \gamma -Ray Spectrum Analyzer.

In this paper, we report on the recent development of a 32-channel low-noise front-end readout ASIC for cadmium zinc telluride (CdZnTe) X-ray and \gamma -ray detectors. Each readout channel includes a charge sensitive amplifier, a CR-RC shaping amplifier and an analog output buffer. The readout ASIC is implemented using TSMC 0.35 - \mu \m mixed-signal CMOS technology, the die size of the prototype chip is 2.2~\mm \times 4.8~\mm. At room temperature, the equivalent noise level of a typical channel reaches 133~\e^ - (rms) with the input parasitic capacitance of 0 pF for the average power consumption of 2.8 mW per channel. The linearity error is less than \pm 2\% and the input energy dynamic range of the readout ASIC is from 10 keV to 1 MeV. The crosstalk between the channels is less than 0.4%. By connecting the readout ASIC to a CdZnTe detector, we obtained a \gamma -ray spectrum, the energy resolution is 1.8% at the 662-keV line of ^137Cs source. [ABSTRACT FROM AUTHOR]