Abstract: Novel schemes for a charge sensitive amplifier (CSA) and a CR-(RC)ⁿ semi-Gaussian shaper in a fully integrated CMOS readout circuit for particle detectors are presented.The CSA is designed with poly-resistors as feedback components to reduce noise.Compared with conventional CSA,the input referred equivalent noise charge(ENC) is simulated to be reduced from 5036e to 2381e with a large detector capacitance of 150pF at the cost of 0.5V output swing loss.The CR-(RC)ⁿ semi-Gaussian shaper uses MOS transistors in the triode region in series with poly-resistors to compensate process variation without much linearity reduction.

Key words: charge sensitive amplifier, shaper, readout circuit, noise optimization