Low power single photon avalanche diode photon counter with peak current suppression technique

A sensor for determining time of flight (ToF), the sensor comprising:

• one or more single photon avalanche diodes (SPADs) configured to detect a first time to digital conversion (TDC) trigger event, wherein the first TDC trigger event includes one or more photons generated as an initial pulse of light of a plurality of pulses of light that interacts with the one or more SPADs, wherein the plurality of pulses is emitted by a source of light;
• one or more latches configured to latch a code from the one or more SPADs, wherein the code is associated with the first TDC trigger event;
• a memory configured to read static random-access memory (SRAM) addressed by the code;
• a counter configured to count the one or more photons of the first TDC trigger event and generate a first histogram of the one or more photons at a first resolution;
• a global window processor configured to read the first histogram and detect a peak of the first histogram;
• a window memory configured to control a single photon avalanche diode (SPAD) controller, wherein the SPAD controller enables the one or more SPADs to detect a second TDC trigger event, wherein the second TDC trigger event includes one or more photons detected as an additional pulse of light of the plurality of pulses of light that interacts with the one or more SPADs during a time span of the peak of the first histogram;
• a delay line configured to delay the propagation of the one or more photons by a predetermined time at a second resolution, wherein the counter is further configured to generate a second histogram of the one or more photons at the second resolution, and
• a global histogram processor configured to detect a peak of the second histogram, wherein the peak of the second histogram determines a distance between the sensor and a target.