ACTIVE PIXEL SENSORS FOR PHOTON COUNTING X-RAY DETECTORS

A photon counting detector includes a plurality of detector sub-modules. Each detector sub-module includes a semiconductor substrate. Each detector sub-module also includes a plurality of active pixels configured to act as detector elements disposed on the semiconductor substrate. Each detector sub-module further includes a plurality of traces extending from the plurality of active pixels to readout circuitry. Each active pixel of the plurality of active pixels is coupled to a respective trace of the plurality of traces. Each active pixel includes an amplification stage configured to generate an output signal based on a current pulse output generated by the active pixel. The photon counting detector also includes the readout circuitry configured to directly read out the output signals from the plurality of active pixels, wherein the readout circuitry is separate from the plurality of detector sub-modules.