Shared readout multiple SPAD event collision recovery for LIDAR
The present disclosure relates to a method and system for time-of-flight detection. There may be two or more photodetectors in a photodetector circuit that capture photon activity. There is logic that processes the responses of the photodetectors and returns the leading edge of the arrival of the first photon and the leading edge of the arrival of the last photon, if at least two photons are received during an overlapping pulse width.
1 . A sensor, comprising:
a photodetector circuit array, comprising at least one photodetector circuit, wherein the at least one photodetector circuit comprises an array of photodetectors, wherein the at least one photodetector circuit further comprises one or more components configured to perform an OR logic operation for combining a pulse that has a pulse width equal to or greater than an original pulse width from the array of photodetectors;
a shared readout line for the at least one photodetector circuit; and
a time to digital converter (TDC) array.
2 . The sensor of claim 1 , wherein the at least one photodetector circuit comprises an array of M by N photodetectors, where M and N are a positive integer wherein at least one of M or N is greater than 1, and wherein the shared readout line is shared by the array of M by N photodetectors of the at least one photodetector circuit.
3 . The sensor of claim 2 , wherein the photodetector circuit is one or more pixels.
4 . The sensor of claim 2 , wherein at least one photodetector in the photodetector circuit is a SPAD or photodiode.
5 . The sensor of claim 2 , wherein the at least one photodetector circuit further comprises OR logic or OR equivalent logic for combining a pulse from the array of M by N photodetectors.
6 . The sensor of claim 1 , wherein the photodetector circuit array comprises an array of M by N photodetector circuits, where M and N are positive integers and at least one of M or N is greater than 1, and wherein the shared readout line is shared by the array of M by N photodetector circuits of the photodetector circuit array.
7 . The sensor of claim 6 , wherein at least one photodetector circuit of the array of M by N photodetector circuits in the photodetector circuit array further comprises OR logic or OR equivalent logic for combining pulses from within the at least one photodetector circuit.
8 . The sensor of claim 6 , wherein the photodetector circuit array further comprises OR logic or OR equivalent logic for combining pulses from the array of M by N photodetector circuits.
9 . The sensor of claim 1 , wherein the TDC array further comprises one TDC per photodetector circuit.
10 . The sensor of claim 1 , wherein the TDC registers timestamps for a leading and trailing edge of a pulse.
11 . The sensor of claim 1 , wherein the photodetector circuit array comprises rows and columns of photodetector circuits, and wherein there is one shared readout line for each row of photodetector circuits in the photodetector circuit array.
12 . The sensor of claim 1 , wherein the at least one photodetector circuit in the photodetector circuit array comprises a plurality of photodetectors.