Novel Charge Sensitive Amplifier Design Methodology suitable for Large Detector Capacitance Applications

Current mode charge sensitive amplifier (CSA) topology and related methodology for use as pre-amplification block in radiation detection read out front end IC systems is proposed1. It is based on the use of a suitably configured current conveyor topology providing advantageous noise performance characteristics in comparison to the typical used CSA structures. In the proposed architecture the noise at the output of the CSA is independent of the detector capacitance value, allowing the use of large area detectors without affecting the system noise performance. Theoretical analysis and simulation analysis are performed concerning the operation – performance of the proposed topology. Measurement results on a current mode CSA prototype fabricated with a 0.35 μm CMOS process by Austriamicrosystems are provided supporting the theoretical and simulation results and confirming the performance mainly in terms of the noise performance dependency on the detector capacitance value.