Linear Tunable Analog Front-End Electronics for Silicon Charged-Particle Detectors

A linear front-end electronic system based on a high-speed charge sensitive amplifier and a tunable shaping amplifier suitable for silicon detectors has been presented. The designed charge sensitive amplifier features simplicity and compactness. It is based on the combination of a low-noise field-effect transistor input device and a current feedback opamp ensuring high frequency and small rise time. The circuit provides both an energy signal and a timing signal. The shaping amplifier is a fifth-order complex filter based on an opamp-RC topology providing a nearly Gaussian response. The shaper also includes a pole-zero cancellation circuit and a base line restorer to preclude the pileup of subsequent input signals. A control system has been developed to adjust the main parameters of the channel. The designed readout channel has been optimized for a medium energy range up to 50 MeV coupled to silicon detectors up to 100 pF. Its feasibility for nuclear physics applications has been experimentally validated.