Strategies to achieve more compact pulse width modulation circuitry for silicon photomultiplier readout

We have shown that a compact, multiplexed PWM circuit based on a gated integrator has successfully identified sub-millimeter width crystals coupled to a PS-SSPM. Multiplexing with our gated integrator front-end shows no flood map degradation in contrast to multiplexing two PS-SSPMs by shorting corresponding channels together, which suffers from signal attenuation due to the device capacitance and added noise from the two devices. In the future we plan to try the gated-integrator technique on larger PS-SSPMs with smaller crystals, and multiplex the readouts of many more PS-SSPMs. This work will facilitate the creation of a O.5mm resolution PET system with a compact PWM readout, and could lead to simplification of readout for existing detectors.