Proximity sensor and method of operating a photodetector based proximity sensor
AssigneeSTMicroelectronics (Research & Development) Limited
InventorJohn Kevin Moore
Life of this patent
Estimating the term…
Abstract
An apparatus can be used for detecting pile-up within circuitry associated with photodetectors. The apparatus includes an input terminal configured to receive a plurality of photodetector outputs. An OR-tree is coupled in parallel with the circuitry associated with the photodetectors. The OR-tree has an input coupled to the input terminal and is configured to combine the photodetector outputs. A counter is configured to count an output of the OR-tree. A comparator is configured to compare an output of the counter to a determined threshold value, wherein the comparator is configured to output an indicator indicating pile-up within the circuitry associated with photodetectors based on the output of the counter being greater than or equal to the determined threshold value.
Claims20
An apparatus for detecting pile-up within circuitry associated with photodetectors, the apparatus comprising:
- a plurality of photodetector outputs coupled to outputs of the photodetectors;
- a main OR-tree having a plurality of inputs coupled to the plurality of photodetector outputs and configured to combine the photodetector outputs to generate information for a histogram;
- a pile-up OR-tree in parallel with the main OR-tree, the pile-up OR-tree having a plurality of inputs coupled to the plurality of photodetector outputs and configured to combine the photodetector outputs;
- a counter configured to count an output of the pile-up OR-tree;
- and
- a comparator configured to compare an output of the counter to a determined threshold value, wherein the comparator is configured to output an indicator indicating pile-up within the circuitry associated with photodetectors based on the output of the counter being greater than or equal to the determined threshold value.
A method for detecting pile-up within circuitry associated with photodetectors, the method comprising:
- receiving a plurality of photodetector outputs at a main OR-tree and a pile-up OR tree in parallel with the main OR tree;
- combining, at the main OR-tree, the photodetector outputs to generate a main OR-tree output comprising information for a histogram;
- combining, at the pile-up OR tree, the photodetector outputs to generate a pile-up OR-tree output;
- counting the combining of the photodetector outputs;
- comparing the counting of the combining to a determined threshold value;
- and
- generating an indicator based on the comparing, wherein the indicator indicates pile-up within the circuitry associated with photodetectors when the counting of the combining is greater than or equal to the determined threshold value.
An apparatus for detecting pile-up within circuitry associated with photodetectors, the apparatus comprising:
- means for receiving a plurality of photodetector outputs;
- a main OR-tree having a plurality of inputs coupled to the plurality of photodetector outputs and configured to combine the photodetector outputs to generate information for a histogram;
- a pile-up OR-tree in parallel with the main OR-tree, the pile-up OR-tree having a plurality of inputs coupled to the plurality of photodetector outputs and configured to combine the photodetector outputs to generate a pile-up OR-tree output;
- means for counting the combining of the photodetector outputs from the pile-up OR-tree output;
- means for comparing the counting to a determined threshold value;
- and
- means for generating an indicator based on the comparing, wherein the indicator indicates pile-up within the circuitry associated with photodetectors when the counting is greater than or equal to the determined threshold value.
An apparatus comprising:
- a plurality of avalanche diode comparators configured to output signals from an associated plurality of avalanche diodes;
- a plurality of pulse shapers, each pulse shaper having an input coupled to an output of an associated avalanche diode comparator;
- a main OR-tree having a plurality of inputs, each input of the main OR-tree being coupled to an output of an associated one of the pulse shapers;
- a fast time to digital converter (TDC) having an input coupled to an output of the main OR-tree;
- a pile-up OR-tree having a plurality of inputs, each input of the pile-up OR-tree being coupled to an output of an associated avalanche diode comparator;
- a counter having an input coupled to an output of the pile-up OR-tree;
- and
- a comparator having a first input coupled to an output of the counter and a second input coupled to a threshold signal node.
Dependencies are inferred from the claim text.