A low-noise, low-power CMOS SOI readout front-end for silicon detectors leakage current compensation with capability

A low-noise, low-power CMOS semiconductor on insulator (SOI) readout front- end aiming to dc coupling to silicon radiation detectors is presented in th is paper. It is able to compensate the leakage current of detectors within a wide range up to 10 muA. While the presented solution does not significan tly deteriorate the amplifier noise performance it complies with demands fo r low-noise readout system for silicon detectors. This front-end system inc ludes a charge-sensitive amplifier, a semi-Gaussian CR-RC shaping amplifier and an output buffer. It has been simulated and implemented in a CMOS SOI- SIMOX process. For no leakage current, an input referred equivalent noise c harge (ENC) of 426 electrons (rms) for 0 pF of detector capacitance with a noise slope of 40 electrons/pF, a peaking time of 50 ns, and a conversion g ain of 23.4 mV/fC have been obtained.