Low Noise Front-end Readout ASIC for 3D Position-Sensitive Pixelated CdZnTe detector

This work presents a low-noise and low-power front-end readout ASIC for 3D position-sensitive Cadmium-Zinc-Telluride (CZT) detectors. The application specific integrated circuit (ASIC) is capable of reading out energy and timing signals from 64 anode pixels and one cathode electrode of pixelated CZT detector simultaneously. Each anode channel provides low-noise charge amplification, high-order shaping, baseline holding, along with peak and timing detection. The input charge ranges from 0.7 fC to 35 fC, corresponding to the particle energy of 20 keV to 1 MeV. The simulation results show that the equivalent noise charge (ENC) of the anode channel is better than 130 $e^{-}$ at a 3 pF input capacitance, and ENC of the cathode channel is better than 300 $e^{-}$ at a 6 pF input capacitance. The time resolution of the anode channel is better than 11 ns at an input charge of 2 fC, and cathode channel is better than 16.5 ns. The power consumption of one channel is less than 2.5 mW with event rate up to 100 ksps.