Low-Power Front-End ASIC for Silicon Photomultiplier

Thanks to its compact structure, mechanical endurance, and low bias voltage, the silicon photomultiplier (SiPM) can be used in small-size applications which require reduced power consumption. In order to detect the light intensity as low as a single photon, the front-end electronics has to amplify and shape the signal of the photodetector. The low-power design cannot impair the performance of readout electronics or limit the capabilities of the SiPM itself. This paper presents a two-channel integrated circuit (IC) designed in Austria Mikro Systeme CMOS 350-nm technology dedicated for the SiPM-based applications. The input stage is a super-common-gate architecture. Each channel of the IC consists of an amplifier and a peak detector with an offset reduction circuit. The power consumption of the single channel is less than 3 mW from the single voltage supply (3.3 V). Moreover, the number of channels of the IC can be easily increased thanks to small dimensions of the circuit. This paper presents a detailed analysis of the IC including: noise performance with adjustment of the input transistor's size, transient and dc simulations of the amplifier and the peak detector, and the introduction of a simple offset reduction technique for the peak detector. The measurement results obtained with two SiPM detectors are presented.