Design of a Multichannel Low-Noise Front-End Readout ASIC Dedicated to CZT Detectors for PET Imaging

Abstract

In this paper, we present the design and preliminary results of a novel low-noise front-end readout application-specific integrated circuit (ASIC) for a PET imaging system whose objective is to achieve the following performances: the spatial resolution of mm , the detection efficiency of 15% and the time resolution of 1 ns. A cascode amplifier based on the PMOS input transistor is selected to realize the charge-sensitive amplifier (CSA) for the sake of good noise performances. The output of the CSA is split into two branches. One is connected to a slow shaper for energy measurements. The other is connected to a fast shaper for time acquisition. A novel monostable circuits is designed to adjust the time delay of the trigger signals so that the peak value of the shaped voltages can be sampled and stored. An eight-channel front-end readout prototype chip is designed and implemented in m CMOS process. The die size is mm mm. The input range of the ASIC is from 2000 e-to 180000 e-, reflecting to the energy level of the gamma ray from 11.2 keV to 1 MeV. The gain of the readout channel is 65 mV/fC. The tested result of ENC is 86.5 e-at zero farad plus 9.3 e-per picofarad. The nonlinearity is less than 3%. The crosstalk is less than 2%. The power dissipation is about 3 mW/channel.

A Prototype VP-PET Imaging System Based on Highly Pixelated CdZnTe Detectors

“…Therefore, we selected only the single-pixel photopeak events of pixelated CdZnTe detectors from the individual CdZnTe pixels. experiments for prototype conventional PET systems using CdZnTe detectors [14,15]. However, few studies have focused on simulating a PET insert system [16].…”

“…Monte Carlo (MC) simulation offers a cost-effective and useful method to understand the imaging ability of a PET based on a pixelated CdZnTe detector [13]. Many studies have reported aspects of both simulations and experiments for prototype conventional PET systems using CdZnTe detectors [14,15]. However, few studies have focused on simulating a PET insert system [16].…”

Nuclear instrumentation and measurement: a review based on the ANIMMA conferences

“…An example of the development of improved electronics for small animal PET imaging with CdZnTe detectors is given in [218]. Similarly, [79] describes ASICs, also coupled to CdZnTe detector arrays, but for photon counting X-ray CT.…”

“…Gao and co-authors [218] describe a very low noise readout ASIC to achieve 1 mm 3 resolution, a detection efficiency of 15%, 1 ns time resolution for gating and better than 2% energy resolution (FWHM) for scatter rejection (Fig. 18).…”

Electron Irradiation Effects and Defects Analysis of the Upright Metamorphic Four‐Junction (UMM4J) Solar Cells

“…A large number of studies on proton and electron irradiation damage fully proved that TJ solar cells exhibit an exceptional irradiation resistance during the entirety of various space missions. [3][4][5][6][7][8] However, the excessive photocurrent in bottom (Ge) cell than that in the top (GaInP) and middle (GaAs) cells implies higher thermalization loss. [9] The thermalization loss can be reduced by adding additional junctions to increase the range of solar spectrum.…”