Radiation detector readout circuit with two-stage charge sensitive amplifier

A two-stage charge sensitive amplifier structure suitable for silicon radiation detector with large capacitance is proposed. It has the advantage that the integration capacitor can be large to reduce the gain sensibility to detector capacitance variation without any stability problem. The feasibility of the proposed circuit is verified by comparing the simulation results with the conventional one-stage charge sensitive amplifier. A prototype of 16-channel readout circuit for electron collection has been taped out in a 0.35μm CMOS technology with a power supply of 5V. The area is 2.5×1.54mm² with 42 pads and the power dissipation is 60mW.