Low-Power Large-Dynamic Range Readout ASIC for VLAST Silicon Strip Detectors

The scientific objects of the very large area gamma-ray space telescope (VLAST) include indirect detection of dark matter particles, gamma-ray astronomy, and cosmic physics. The silicon tracker and low-energy gamma-ray detector (STED) of the VLAST collect the electron-hole pairs converted from the high-energy gamma photons. The STED contains 16 silicon strip detector layers, each with a sensitive area of more than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.8\times 2.8$ </tex-math></inline-formula> m. In total, there are 1376256 detector channels, and each channel has a sizeable equivalent capacitance of ~100 pF. To meet the stringent requirements of VLAST, we have designed a readout application specific integrated circuit (ASIC) named SiReadout for the silicon detectors. Each readout channel can measure the charge of the detector and provide trigger information. This article will discuss the design and performance of this SiReadout ASIC.