Ultra-Fast Digital Silicon Photomultiplier with Timestamping Capability in a 110 nm CMOS Process
Year: 2026
Type: article
Abstract: A monolithic digital Silicon Photomultiplier (SiPM) featuring 1024 microcells with a 30-micrometer pitch and a 50% fill factor has been designed in a 110-nanometer CMOS image sensor technology. The device under consideration integrates both SPAD sensors and front-end electronics in the same substrate. It can count up to 1024 photons in less than 22 ns, while assigning timestamps to the first and last detected photons with a time resolution of less than 100 ps. A parallel counter structure combined with a fast adder tree provides photon counting in digital form with low latency, whereas a carefully balanced fast NAND tree ensures a fixed-pattern time uncertainty not exceeding 26 ps. The architecture incorporates in-pixel memory for individual cell disabling and configurable thresholding on the timing signal for noise mitigation. In order to optimize the fill factor, a part of the electronics is placed outside the array, while the most sensitive elements of the timing and counting circuits are laid out close to the sensor, in the SPAD array. A serial readout is employed to provide a single output connection per SiPM, thereby simplifying system integration.
Source: Electronics
Institutions: Istituto Nazionale di Fisica Nucleare, University of Pavia, Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, University of Naples Federico II, University of Padua, Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Istituto Nazionale di Fisica Nucleare, Sezione di Bari, University of Trento, Istituto Nazionale di Fisica Nucleare, Trento Institute for Fundamental Physics And Applications, Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, University of Insubria, Istituto Nazionale di Fisica Nucleare, Sezione di Milano
Language: English
Subfield: Instrumentation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,896
OpenAlex ID: W7138971505