 Every SPAD in SiPM operates in Geiger mode and is coupled with the others by a metal or polysilicon quenching resistor.Although the device works in digital/switching mode, most of SiPM are an analog device because all the microcells are read in parallel, making it possible to generate signals within a dynamic range from a single photon to 1000 photons for a device with just a square-millimeter area.More advanced readout schemes are utilized for the lidar applications.