Low power readout circuits for large area silicon photomultiplier array

In this paper we present modeling and experimental characterization of two passive charge division circuits as low power readout systems for large area silicon photomultiplier (SiPM) array. The first configuration is the traditional discrete positioning circuit (DPC), while the second one is a symmetric charge division circuit where the SiPM output current is split into two symmetric signals by a pair of diodes. Testing the two CDC networks on a 16×28 array of SiPMs, we found that image reconstruction is significantly compromised when the DPC configuration is connected to few SiPMs, while the diode-based CDC configuration presents a very high quality image histogram independently on the number of the connected photosensors. These results demonstrate the efficacy of the proposed diode-based CDC as passive readout circuitry and open the route for the development of effective low-power consumption, portable gamma camera systems.