SymPET, a waveform digitizing "System on Chip" for ultra-high resolution TOF PET: design concept and preliminary studies.

SymPET is a low-power, high channel density, waveform-digitizing readout microchip under development at Nalu Scientific for SiPM-based TOF PET applications. Our "System on Chip" waveform digitizing architecture includes features such as fully random accessible analog storage, input triggering, and on-chip biasing, control and waveform feature extraction capabilities, enabling many effective mechanisms to optimize features such as e.g., throughput, speed, and buffer length while simultaneously allowing excellent control of systematic effects which typically significantly affect the timing precision of time-over-threshold based readouts. Preliminary results show that SymPET can provide less than 10 ps timing jitter at a reasonable power budget which is substantially better compared to existing solutions. This will allow for high-channel density and/or limited angle applications such as ultra high resolution brain TOF PET designs that require proper management of heat dissipation, while necessitating high spatial and timing resolution.