A Low-Noise 32-Channel Readout Circuit for Silicon Drift Detectors Aimed to X-Ray Imaging

Abstract

This work presents a low-noise low-power readout circuit aiming to DC coupling to silicon drift detectors (SDDs). Two circuit structures for leakage current compensation are proposed and compared. The leakage current compensation range of the version 1 circuit reaches 9 nA, the simulated equivalent noise charge (ENC) is 26 e ^- + 30 e ^- /pF, the input charge range is from 0.1 fC to 0.5 fC and the gain is 840 mV/fC. The leakage current compensation range of the version 2 circuit reaches 200 nA, the simulated ENC is 59 e ^- + 22 e ^- /pF, and the input charge range is from 0.1 fC to 0.5 fC and the gain is 710 mV/fC. The chosen technology is a standard commercial 1P6M 0.18 μm mixed-signal CMOS process and the chip area is 1.0 × 3.3 mm ² .