Room: AAPM ePoster Library
For PET instrumentation development, it is still challenging to read out and process signals from multi-channel Silicon Photomultiplier (SiPM) arrays, particularly if compact electronics size is required. We are developing a multiple-channel dual-polarity readout ASIC chip for Time-Of-Flight (TOF) PET applications.
This SiPM readout ASIC (SiPMROC) consists of 16 individual channels for energy measurement, a summing channel for timing measurement, control and configure blocks, and LVDS transceivers. A low-impedance high-bandwidth pre-amplifier is deployed in each channel to read out the current signal of one SiPM, and its output is split into two for signal summing and for signal energy digitizing. The summing channel collects signals from all 16 channels for total energy measurement and timing pickoff based on a current comparator for leading edge discrimination, and also outputs a duplicated current signal for multi SiPMROC’s cascading application. SiPMROC can operate automatically after configured properly and generate a stream of differential digital signals containing energy information of all channels and a differential timing signal.
Simulation shows that the maximal event rate can reach 1 Mevent/s per chip. Its dynamic range varies from 100 fC to 400 pC. The power consumption of one individual channel is 10 mW by operating at 2.5 V. The circuit design has been completed; the chip fabrication is underway with a commercial 65 nm CMOS fab technology; the chip size is 1?3 mm2 and will be packaged in a QFN 64 with footprint less than 1cm2.
We have designed SiPMROC as a compact SiPM readout ASIC for multi-channel SiPM readout with accurate energy and high precision timing measurement, as shown by the simulation. It is expected that the evaluation of the circuit performance and the test of related PET detector imaging capability based on using this ASIC will be reported in the conference.