PETsys SiPM Readout System

PETsys Silicon Photomultiplier Readout System

The PETsys SiPM Readout System is designed to read a large number of SiPM photo-sensor pixels in applications where a high data rate and excellent time resolution is required. It is based on the TOFPET2 ASIC (Fig. 1). This is a low power ASIC with 64 channels optimised for reading SiPMs for Time Of Flight PET applications. The ASIC is the interface between the analog signals from the photo-sensors and the digital readout. Every time one of the 64 channels in the ASIC exceeds the threshold, a record is created giving the channel number, the time and the charge of the event. The rest of the readout chain only handles digital information. Coincidence filtering is implemented in the firmware. The data are transferred to the computer using the PCIe bus.
The readout system has three main components: the Front-End Modules (Fig. 2), the FEB/D boards (fig 3) and the DAQ board (fig 4). Together these allow assembling a complete and scalable data acquisition system reading tens of thousands of SiPMs

Figure 1 64 channel TOFPET2 ASIC (before globtop is applied)

Figure 2: The PETsys front-end module is the interface between the analog signals of the photo-sensor and the digital readout chain.


Figure 3: The PETsys FEB/D_V2 collects data from 8 Front-End Modules and sends the data to the DAQ board in the DAQ computer.

Figure 4: The DAQ board plugs into the PCIe bus of the DAQ computer.