Fiber Tracker Readout BETA ASIC for the High Energy Cosmic Radiation Detection (HERD) facility

This work presents the BETA ASIC developed for the SiPM readout of the Scintillating Fiber Tracker (FIT) at the High Energy Cosmic-Radiation Detection (HERD) facility. The main target of this ASIC is to track the minimum ionizing particles (MIPs) and perform a charge measurement of the detected events. The 16-channel BETA ASIC is implemented in a 130 nm technology and the signal processing has a nominal power consumption of 1 mW/ch. The ASIC includes a dual-gain scheme automatically configured depending on the incoming signal that provides a high dynamic range from 3800 pe to 0.1 pe. Signal to noise ratio at single photon level is about ≈13. The ASIC also contains 2 discriminators that can provide trigger signals with time jitter down to 80 ps sigma for 10 photo-electrons. A linearity error of the charge measurement of 3% for a dynamic range as large as 15 bits. Finally, on-chip digital back-end circuitry controls the acquisition, and data serialization to a single output link.