Shared sample and convert capacitor architecture
AssigneeWaymo LLC
InventorsVadim Gutnik, Andrew Abo
Life of this patent
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Abstract
A LIDAR device includes an input node, an output node, and a sample-and-convert circuit. The input node receives a photodetector signal, and the output node generates an output signal indicating a light intensity value of the photodetector signal. The sample-and-convert circuit includes a number of detection channels coupled in parallel between the input node and the output node. In some aspects, each of the detection channels may be configured to sample a value of the photodetector signal during the sample mode and to hold the sampled value during the convert mode using a single capacitor.
Claims20
A LIDAR detector circuit, comprising:
- an input node to receive a photodetector signal;
- an output node to generate an output signal indicating a light intensity value of the photodetector signal;
- and
- a sample-and-convert circuit including a number of detection channels coupled in parallel with each other between the input node and the output node, each of the detection channels comprising:
- a comparator;
- a capacitor configured to capture a value of the photodetector signal, wherein the capacitor includes a first plate and a second plate;
- a first switch configured to selectively couple the first plate of the capacitor to the photodetector signal;
- and
- a second switch configured to selectively couple the second plate of the capacitor to a supply voltage.
A LIDAR device, comprising:
- a photodetector configured to generate a photodetector signal based on received light pulses;
- a mode selection circuit to receive the photodetector signal and configured to operate in at least a sample mode and a convert mode;
- and
- a sample-and-convert circuit including a number of detection channels connected in parallel with each other, each of the detection channels configured to sample a value of the photodetector signal during the sample mode and to hold the sampled value during the convert mode.
A method of determining a light intensity value of a photodetector signal, the method comprising:
- providing the photodetector signal to a capacitor having first and second plates;
- capturing a value of the photodetector signal as a differential voltage across the capacitor;
- holding the differential voltage across the capacitor;
- selecting a digital code word based, at least in part, on a comparison between the differential voltage and a reference voltage;
- and
- identifying a value of the digital code word as an indication of the captured value.
Dependencies are inferred from the claim text.