A mechanism for radiation detection is disclosed. An integrated circuit usable in detecting radiation includes a plurality of readout circuits is described. A readout circuit of the plurality of readout circuits includes an integration capacitor and an averaging capacitor. The integration capacitor is coupled with a pixel of a photodetector pixel array. The pixel has a pixel area. An available area less than the pixel area is usable for layout of the integration capacitor. The integration capacitor has a capacitor area less than the available area. The averaging capacitor has an averaging capacitance greater than the integration capacitance of the integration capacitor. In some aspects, the integrated circuit further includes at least one cascaded averaging circuit coupled with the averaging capacitor.