Development of Ultrawide Dynamic Range Readout ASICs for Radiation Monitoring in Space

A set of readout application-specific integrated circuits (ASICs) has been developed for semiconductor detectors for space radiation monitoring, including an analog front-end (WDDose-AFE) chip and a digital signal-processing (WDDose-DSP) chip with a waveform sampling analog-to-digital converter (ADC). The WDDose-AFE chip consists of a preamplifier, followed by multigain stages of shapers and fully differential output buffers for each channel. The WDDose-DSP chip integrates a successive approximation register (SAR) ADC in 10-bit and 100 MSPS, a digital trapezoidal filter, and peaking detection logic for each channel. The prototype chips of WDDose-AFE and WDDose-DSP were fabricated in 180- and 65-nm CMOS, respectively. The single-channel power consumptions of WDDose-AFE and WDDose-DSP were measured to be only 13.6 and 11.3 mW. The input dynamic range of WDDose-AFE was up to 4.4 pC for the low-gain stage, while the equivalent noise charge (ENC) was less than 1200e $^{-}$ for the high-gain stage with 50-pF input capacitance. The ASIC chips were also measured with silicon detectors and electron and ion beams. The detailed circuit design and test results will be presented in this article.