어레이 타입 실리콘 광전증 배관의 신호 보상을 위해 밀러 효과를 이용한 입력 회로 시뮬레이션

Simulation Results of Signal Compensation Circuit using Miller Effect for Array-Type SiPM Sensors

This work presents a novel configuration of front-end circuits for array-type SiPM-based radiation detectors to enable multiplexing to reduce the effective number of readout channels while maintaining high quality pulse information. The major component of the proposed configuration, a bootstrap amplifier exploiting the Miller effect, keep the same AC voltages of two sides of a detector, resulting in no effective detector capacitance between the nodes. This technique ideally allows combining channels without any performance degradation in terms of rise time and amplitude of signals that can be caused due to the accumulated capacitance when detectors are shorted in parallel in a signal multiplexing scheme. In order to verify the configuration, we designed and built a test board inserting a unity-gain amplifier between a 16-pixel SiPM array and a conventional charge-sensitive amplifier as a preamplifier. The simulated pulses at the output of the front-end system show that the bootstrap technique can successfully mitigate performance degradation of rise time and amplitude. This technique can be adopted in many applications that require a multiplexed readout of a large area of photodetectors, for instance, in cargo scanning technologies, radiation monitoring in nuclear plant facilities or developing advanced medical imaging instruments such as PET and SPECT.