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

A low-noise, low-power CMOS semiconductor on insulator (SOI) readout front-end aiming at dc coupling to silicon radiation detectors is presented in this paper. It is able to compensate the leakage current of detectors within a wide range up to 10 /spl mu/A. While the presented solution does not significantly deteriorate the amplifier noise performance it complies with demands for low-noise readout system for silicon detectors. This front-end system includes 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 charge (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 gain of 23.4 mV/fC have been obtained.