A Novel Analog Front-End Readout Circuit ASIC With High Response Speed for 4H-SiC Trench Schottky-Type Neutron Detector

In this article, a novel 4H-silicon carbide (SiC) trench Schottky-type neutron detector dedicated interface application-specific integrated circuit (ASIC) with extremely fast-response speed and low noise is proposed. The new interface ASIC adopts a new dual-output charge-sensitive amplifier (CSA) and proposes a feedback discharge module. The high gain of the CSA and the high impedance of the feedback discharge module are the prerequisites for improving the response speed. Due to the proposal and use of a novel fast Gaussian active forming filter, a faster processing speed can be provided at less cost. The high-speed and high-resolution discriminator has a small time shift, so it is essential for accurately determining the arrival of a radiation event. The readout circuit chip is based on a 0.18- $\mu $ m CMOS process and is powered by a 5-V supply. The readout circuit has a response speed of only 40 ns with a conversion gain of 69 mV/fC and an equivalent noise charge (ENC) of 37e $^{-}$ . Simulated at different corners, the proposed readout ASIC has excellent linearity with a nonlinearity error of only 1.65%. The experimental results show that the response speed is significantly improved compared with the conventional readout chip.