A 0.35µm Low-Noise Stable Charge Sensitive Amplifier for Silicon Detectors Applications

Abstract

The Charge Sensitive Amplifier (CSA) is the key module of the front-end electronics of various types of Silicon detectors and most radiation detection systems. High gain, stability, and low input noise are the major concerns of a typical CSA circuit in order to achieve amplified susceptible input charge (current) for further processing. To design such a low-noise, stable, and low power dissipation solution, a CSA is required to be realized in a complementary metal-oxide-semiconductor (CMOS) technology with a compact design. This research reports a low-noise highly stabile CSA design for Silicon detectors applications, which has been designed and validated in TSMC 0.35 um CMOS process. In a typical CSA design, the detector capacitance and the input transistor's width are the dominant parameters for achieving low noise performance. Therefore, the Equivalent Noise Charge (ENC) with respect to those parameters has been optimized, for a range of detector capacitance from 0.2 pF - 2 pF. However, the parallel noise of the feedback was removed by adopting a voltage-controlled NMOS resistor, which in turn helped to achieve high stability of the circuit. The simulation results provided a baseline gain of 9.92 mV/fC and show that ENC was found to be 42.5 e-with 3.72 e-/pF noise slope. The Corner frequency exhibited by the CSA is 1.023 GHz and the output magnitude was controlled at -56.8 dB; it dissipates 0.23 mW with a single voltage supply of 3.3 V with an active die area of 0.0049 mm2 Copyright 2020 by the Authors.