Configurable low noise readout front-end for gaseous detectors in 130nm CMOS technology

A noise improved Charge Sensitive Amplifier (CSA) topology for a gaseous detector readout front-ends is presented. The proposed topology is based on the traditional cascode topology with addition of a PMOS to partially cancel the channel thermal noise and the flicker noise of the CSA input transistor. A noise improvement of about 23% was obtained without increasing power consumption. Additionally, the proposed circuit reduces the dependence of the noise on the detector capacitance. A chip with 5 front-ends channel implemented with the proposed CSA topology and a Semi-Gaussian shaper of 4^th order was designed in TSMC 130nm CMOS technology. The fabricated front-end was designed for 160ns of peaking time, sensitivity of 30mV/fC and Equivalent Noise Charge (ENC) of 428e. The measured power consumption of the CSA and of the pulse shaper were 3.3mW and 4.2mW, respectively.