Analisi e progettazione di sistemi di alimentazione a basso rumore e interfacce analogiche integrate per applicazioni di fotorivelazione basati su fotomoltiplicatori al Silicio

This thesis focuses on the development of a low-noise power supply and an integrated analog interface for photodetection applications that involve Silicon Photomultipliers (SiPMs). SiPMs are modern solid-state photon sensors offering exceptional sensitivity and timing resolution, making them suitable for applications ranging from high-energy and nuclear physics experiments to high-sensitivity imaging. For nuclear physics experiment, such as the dark matter detection in DarkSide-20k, a key is the design of a modular Voltage Supply Unit (VSU) for SiPM tiles with particularly low output noise. This is crucial for such an application, since the switching spikes can interfere with proper operation of the front-end electronics, mimic the photon detection behavior. The design of the VSU incorporates a flyback DC-DC converter and a linear regulator with multiple noise suppression techniques known in the literature. Measurements demonstrate the validity of the designed VSU, achieving noise levels below 1 mV for both peak-to-peak and RMS over a wide frequency range, exceeding the requirements for stable SiPM operation. In the field of high-sensitivity cameras, SiPMs offer a fashionable alternative to common CMOS sensors. However, integration of the front-end electronics as in the digital SiPMs results in extremely high costs and difficulty of tuning and integration between the two elements. The ATARI project aims to develop an active carrier that integrates the front-end electronics, to be attached to the SiPMs through modern 3D-bonding techniques. In this context, an analog front-end for SiPM to be used as pixel-channel in ATARI has been designed. The interface is able to retrieve photon time and charge information provided by the SiPM, with a very low-impedance input Transimpedance Amplifier (TIA). This shows a linear response up to 30 detected photons, with an output of approximately 50 mV per photoelectron. The charge integrator exhibits enhanced sensitivity for low photon counts, thanks to an integrated non-linear capacitance. The Time-to-Digital Converter (TDC) achieves a time resolution of 5 ns if using a 20 MHz clock. This research contributes to the advancement of SiPM technology, presenting solutions for low-noise bias voltage and the design of integrated SiPM front-end.