Silicon-Photomultiplier (SiPM) Protection Against Over-Current and Over-Illumination

SiPMs operate in Geiger mode, wherein photodiode cells are reverse-biased to the breakdown by even a single photon. Each cell is connected in series with a quenching resistor, which prevents cell damage and resets the cell after making a signal. All cells are arranged in parallel, making SiPMs and biasing circuits vulnerable to over-illumination, where the current passing through the SiPM can exceed the allowable value, leading to damage. In this study, we investigate over-current conditions in SiPMs and propose a protective method against over-illumination and over-current using a series resistor. Additionally, we ensure SiPM stability through the incorporation of a suitable capacitor.