US Patent 10964742 Germanium-silicon light sensing apparatus II

A circuit that includes: a photodiode configured to absorb photons and to generate photo-carriers from the absorbed photons; a first MOSFET transistor that includes: a first channel terminal coupled to a first terminal of the photodiode and configured to collect a portion of the photo-carriers generated by the photodiode; a second channel terminal; and a gate terminal coupled to a first control voltage source; a first readout circuit configured to output a first readout voltage; a second readout circuit configured to output a second readout voltage; and a current-steering circuit configured to steer the photo-carriers generated by the photodiode to one or both of the first readout circuit and the second readout circuit.