Abstract: The subject technology is directed to systems and methods for sensor baseline detection and compensation. In an embodiment, the subject technology provides an apparatus comprising a first amplifier configured to receive a current signal and generate a first voltage signal associated with the current signal. The apparatus also comprises a first circuit configured to generate a second voltage signal based on the first voltage signal. The first circuit further comprises a switch configured to adjust the second voltage signal in response to changes in the first voltage signal, and a control circuit configured to control the rate of adjustment of the second voltage signal. There are other embodiments as well.

Abstract: An example apparatus for temperature compensation in an imaging system is described. The apparatus includes an analog front end configured to receive a signal from a detector of the imaging system, the analog front end being integrated in an integrated circuit (IC) electrically and thermally coupled to the detector; a low-pass filter coupled to an output of the analog front end and configured to output a first signal; a first circuit configured to output a second signal based on power consumed by the IC; and a second circuit configured to receive the first and second signals and output a third signal in response to the first and second signals.

Abstract: A system for enhancing digital signal event counting is provided. The system includes a pulse filter coupled between a plurality of comparators and a plurality of counters. The pulse filter is configured to generate a refined signal associated with a rising edge and a falling edge of each comparator output corresponding to a threshold level. The pulse filter identifies the timing characterization of at least two refined signals respectively corresponding to a lower threshold level and a next higher threshold level and generates a trigger signal corresponding to an event counting based on the timing characterization associated with both the rising edge and the falling edge. Corresponding counters increment a count at the lower threshold level or both the lower threshold level and the next higher threshold level for each event counting based on the trigger signal.

Abstract: The subject technology is directed to light detection and ranging (LIDAR) systems and methods. In an embodiment, the subject technology provides a device comprising an optical module configured to receive a first optical signal and a first circuit configured to generate a first electrical signal based on the first optical signal. The device also comprises a first comparator configured to generate a second electrical signal by comparing the first electrical signal to a first threshold value. The device further comprises a first filter configured to generate a first pulse based on the second electrical signal. The first pulse comprises a first point associated with a first timestamp. The timestamp data may be briefly retained in the analog domain, followed by subsequent digital conversion, allowing for significant power savings and reduced system bandwidth. There are other embodiments as well.

Abstract: The present invention is directed to electrical circuits. In a specific embodiment, a first interface circuit is coupled to a first plurality of ports for processing signals at a first frequency range, and a second interface circuit is coupled to a second plurality of ports for processing signals at a second frequency range. The first interface circuit is coupled to a timing channel circuit. The second interface circuit is coupled to an energy channel circuit. There are other embodiments as well.

Abstract: Systems and circuits directed to a time-of-flight measurement system are provided. More specifically, an illustrative optical sensor is disclosed to include a plurality of avalanche photodiodes, at least one of the plurality of avalanche photodiodes being in communication with amplifier common node through an impedance converter that is responsive to a control signal and selectively connects or disconnects the at least one avalanche photodiode from the common node based on the control signal. In an example, the impedance converter is also configured to preserve current generated from the at least one avalanche photodiode.

Abstract: A semiconductor substrate includes a first surface including an optical detection section that converts optical signals into electrical signals. The semiconductor substrate includes a second surface opposite the first surface and including one or more first contacts electrically connected to the optical detection section to communicate the electrical signals from the optical detection section to another substrate. The semiconductor substrate includes a temperature sensing element that includes a resistive structure on at least the first surface or the second surface. The resistive structure has a resistance that varies with temperature.

Abstract: Systems and circuits directed to a time-of-flight measurement system are provided. More specifically, an illustrative optical sensor is disclosed to include a plurality of avalanche photodiodes, at least one of the plurality of avalanche photodiodes being in communication with amplifier common node through an impedance converter that is responsive to a control signal and selectively connects or disconnects the at least one avalanche photodiode from the common node based on the control signal. In an example, the impedance converter is also configured to preserve current generated from the at least one avalanche photodiode.

Abstract: A configurable light source driver device includes circuitry that detects the presence of a resistor when connected to a terminal of the device and automatically configures the device to operate as a differential driver circuit with low EMI emission and a level of circuit stability that is selected on the basis of parasitic impedance conditions of the differential driver circuit. When the terminal is left unconnected, the configurable light source driver device automatically configures itself to operate as a single ended driver circuit with low power consumption and a different level of circuit stability that is selected on the basis of parasitic impedance conditions of the single ended driver circuit. Furthermore, the configurable light source driver device can include a pulse width adjustment circuit for modifying certain operating characteristics of each of the differential driver circuit and the single ended driver circuit.

Abstract: Systems and circuits directed to a time-of-flight measurement system are provided. More specifically, the time-of-flight measurement system may include an optical sensor module including a substrate of a first conductivity type having an epitaxial layer disposed thereon, a photodetector formed in the first epitaxial layer, a deep well of a second conductivity type formed in the first epitaxial layer, a deep well of the first conductivity type formed in the deep well of the second conductivity type, a well of the second conductivity type formed in the deep well of the first conductivity type, and a well of the first conductivity type formed in the deep well of the first conductivity type. The time-of-flight measurement system may include control logic configured to determine a distance based on a time-of-flight value received from the photodetector.

Abstract: An optical measurement system is provided for performing time-of-flight distance measurement with ambient light suppression. The system has a detector circuit that includes a photodetector and an additional current gain element that amplifies the photocurrent produced by the photodetector. Placement of the additional current gain element near the photodetector allows low-power optical signals to be detected without amplifying noise from sources of the system that are outside of the detector circuit, thereby allowing a high signal-to-noise ratio to be achieved. Embodiments of the system include circuitry that automatically regulates the bias voltage of the photodetector to compensate for temperature and for fabrication process variations.

Abstract: An optical measurement system includes a photodetector coupled in series with a field effect transistor (FET) that is a part of a sample and hold circuit. When the sample and hold circuit is in a sampling mode of operation, a voltage bias is applied to the FET and the photodetector is exposed to ambient light, thus resulting in a first current flow through the photodetector. One of several components can be selected in the sample and hold circuit for obtaining a desired time constant. When the sample and hold circuit is subsequently placed in a hold mode of operation, a second current flows through the photodetector due to exposing of the photodetector to a combination of ambient light and light associated with an optical measurement. A portion of the second current that is attributable to the light associated with the optical measurement is used for executing the optical measurement.

Abstract: An optical measurement system is provided for performing time-of-flight distance measurement with ambient light suppression. The system has a detector circuit that includes a photodetector and an additional current gain element that amplifies the photocurrent produced by the photodetector. Placement of the additional current gain element near the photodetector allows low-power optical signals to be detected without amplifying noise from sources of the system that are outside of the detector circuit, thereby allowing a high signal-to-noise ratio to be achieved. Embodiments of the system include circuitry that automatically regulates the bias voltage of the photodetector to compensate for temperature and for fabrication process variations.

Abstract: An optical measurement system includes a photodetector coupled in series with a field effect transistor (FET) that is a part of a sample and hold circuit. When the sample and hold circuit is in a sampling mode of operation, a voltage bias is applied to the FET and the photodetector is exposed to ambient light, thus resulting in a first current flow through the photodetector. One of several components can be selected in the sample and hold circuit for obtaining a desired time constant. When the sample and hold circuit is subsequently placed in a hold mode of operation, a second current flows through the photodetector due to exposing of the photodetector to a combination of ambient light and light associated with an optical measurement. A portion of the second current that is attributable to the light associated with the optical measurement is used for executing the optical measurement.

Abstract: An optical detection system can include a set of photodetectors and a set of pixel processing circuits for processing pixel information provided by the set of photodetectors. A set of switches interposed between the set of photodetectors and the set of pixel processing circuits can be selectively activated to place the optical detection system in a first mode of operation that allows for optical detection using a subset of pixel processing circuits. The remaining pixel processing circuits that are not used during the first mode of operation can be placed in a power down condition for conserving power. The set of switches can then be re-activated as needed, to place the optical detection system in a second mode of operation that allows for optical detection using a larger number of pixel processing circuits than used during the first mode of operation.

Abstract: An optical fiber strain sensor system and method are provided that prevent mechanical stresses exerted on the portions of the optical transmission path that leads from the measurement equipment to the structure and that leads from the structure back to the measurement equipment from having an influence on the phase difference measurement. In addition, the optical strain sensor system and method can be implemented with a reduced amount of optical fiber and a reduced number of optical connectors, thereby reducing overall system cost while improving measurement accuracy.

Abstract: A configurable light source driver device includes circuitry that detects the presence of a resistor when connected to a terminal of the device and automatically configures the device to operate as a differential driver circuit with low EMI emission and a level of circuit stability that is selected on the basis of parasitic impedance conditions of the differential driver circuit. When the terminal is left unconnected, the configurable light source driver device automatically configures itself to operate as a single ended driver circuit with low power consumption and a different level of circuit stability that is selected on the basis of parasitic impedance conditions of the single ended driver circuit. Furthermore, the configurable light source driver device can include a pulse width adjustment circuit for modifying certain operating characteristics of each of the differential driver circuit and the single ended driver circuit.

Abstract: An Integrated Circuit, a system, and a method are provided. The disclosed Integrated Circuit may include a plurality of pads exposing internal components of the Integrated Circuit to external circuits, a digital interface connectable to the plurality of pads, an analog interface connectable to the plurality of pads, and sensing circuitry configured to detect whether a digital circuit or an analog circuit is externally connected to the plurality of pads and based on such detection selectively connect at least one of the digital interface and analog interface to the plurality of pads.

Abstract: An optical fiber strain sensor system and method are provided that use pixels of a three-dimension (3-D) pixel sensor to sense the respective light beams passing out of the ends of a reference fiber and a measurement fiber and for converting the respective light beams into respective electrical signals. Because 3-D camera pixels have photodiodes that are directly connected by switches to integrators within the same die, the need to use separate TIAs and phase detection circuitry in each receive channel is eliminated, which reduces system complexity and overall cost. In addition, omitting the separate TIAs and phase detection circuitry for each channel eliminates the phase uncertainty that can occur when using those components, and thus improves measurement precision.

Abstract: An opto-sensitive device, a pixel configured for use in an opto-sensitive device, and a method of operating an opto-sensitive device are disclosed. The opto-sensitive device illustratively includes a capacitor stacked on top of a photodetector, thereby improving the fill factor of the opto-sensitive device. Transparent properties of the capacitor for a wavelength of interest ensure that the incident light is completely or mostly absorbed only within the photodetector and not within the capacitor.