Abstract: In described examples, an integrated circuit includes a modulator configured to modulate a driving signal for an optical transmitter with a narrow band modulation signal in which the driving signal with a fixed duration is transmitted to the optical transmitter periodically. The integrated circuit also includes a demodulator configured to receive a signal from an optical receiver that is configured to receive a reflection of light transmitted by the optical transmitter off an object, the demodulator configured to discriminate the narrow band modulation signal and estimate a distance of the object using the narrow band modulation signal.

Abstract: A transducer system. The system comprises a transducer and circuitry for applying an excitation waveform to excite the transducer during an excitation period. The circuitry for applying has: (i) circuitry for applying a first waveform at a first frequency; and (ii) circuitry for applying a second waveform at a second frequency differing from the first frequency.

Abstract: A sensor circuit includes a sensor array. The sensor array includes a sensor row that includes a first sensor cell, a second sensor cell, and an output stage of a distributed amplifier circuit. The first sensor cell includes a first photodetector, and a first preamplifier stage of the distributed amplifier circuit. The first preamplifier stage is coupled to the first photodetector, and is configured to amplify a signal received from the first photodetector. The second sensor cell includes a second photodetector, and a second preamplifier stage of the distributed amplifier circuit. The second preamplifier stage is coupled to the second photodetector, and is configured to amplify a signal received from the second photodetector. The output stage of the distributed amplifier circuit is coupled to the first and second sensor cells, and is configured to amplify a signal received from the first preamplifier stage and the second preamplifier stage.

Abstract: A transducer system. The system comprises a transducer and circuitry for applying an excitation waveform to excite the transducer during an excitation period. The circuitry for applying has: (i) circuitry for applying a first waveform at a first frequency; and (ii) circuitry for applying a second waveform at a second frequency differing from the first frequency.

Abstract: Described example aspects include an integrated circuit includes a timing controller configured to select a selected time slot in a measurement period having a plurality of time slots and a transmit driver configured to provide a transmit signal in accordance with the selected time slot, in which the transmit signal is transmitted to an optical transmitter. The integrated circuit also includes a range estimator configured to receive a received signal after the selected time slot from an optical receiver that is configured to receive a reflection of light transmitted by the optical transmitter off an object, the range estimator configured to determine an estimated distance of the object based on the received signal.

Abstract: An optical distance measuring system includes a transmitter and a receiver. The transmitter is configured to generate a first optical waveform and direct the first optical waveform toward a first scan point within a field of view (FOV). The receiver is configured to receive the first optical waveform reflected off a first object within the FOV, direct the first optical waveform reflected off the first object to a first photodiode group of an array of photodiode elements, and determine a distance to the first object based on a time of flight of the first optical waveform from the transmitter to the first object and back to the receiver.

Abstract: Described examples include an integrated circuit that includes an encoder configured to modulate a driving signal for an optical transmitter with a plurality of encoded pulses corresponding to a code, in which the driving signal is transmitted to the optical transmitter periodically. The integrated circuit also includes a demodulator configured to receive a received signal from an optical receiver that is configured to receive a reflection of light transmitted by the optical transmitter off an object, the demodulator configured to discriminate the plurality of encoded pulses in the received signal and estimate a distance of the object.

Abstract: Described example aspects include an integrated circuit includes a timing controller configured to select a selected time slot in a measurement period having a plurality of time slots and a transmit driver configured to provide a transmit signal in accordance with the selected time slot, in which the transmit signal is transmitted to an optical transmitter. The integrated circuit also includes a range estimator configured to receive a received signal after the selected time slot from an optical receiver that is configured to receive a reflection of light transmitted by the optical transmitter off an object, the range estimator configured to determine an estimated distance of the object based on the received signal.

Abstract: Systems and methods for color Doppler imaging in an ultrasound imaging system are disclosed herein. An ultrasound imaging system includes color Doppler imaging circuitry. The color Doppler imaging circuitry is configured to estimate flow parameters. The imaging circuitry includes a radio frequency (“RF”) demodulator configured to produce in-phase and quadrature components of an ultra-sound data vector. The RF demodulator includes a table in memory that stores interleaved sine and cosine values. The RF demodulator maintains an index value for the table having higher precision than is used to index the table. The RF demodulator rounds the index value for each access of the table. Each table access retrieves a sine value and a cosine value.

Abstract: A method includes reading first and second timer count values from a timer. The first timer count value is associated with a first time point, and the second timer count value is associated with a second time point. Also, the method includes calculating a difference between the first and the second timer count values, and determining whether the difference is within a range. The range is based on a desired executing frequency to perform a computing task, a variation of the desired executing frequency, and a timer frequency. Further, based on the difference not being within the range, the method includes setting an error flag value to be true and incrementing an error count value.

Abstract: A method includes reading first and second timer count values from a timer, wherein the first timer count value is associated with a first time point and the second timer count value is associated with a second time point, calculating a difference between the first and the second timer count values, and determining whether the difference is within a range, wherein the range is based on a desired executing frequency to perform a computing task, a variation of the desired executing frequency, and a timer frequency. Further, based on the difference not being within the range, the method includes setting an error flag value to be true and incrementing an error count value.

Abstract: Methods and apparatus to determine an accurate distance to a target using reference signal interpolation is disclosed. An example apparatus includes an interpolator to receive a first sample of a reference signal and a second sample of a reference signal; and interpolating a reconstructed reference signal sample based on the first and second samples, the reconstructed reference signal corresponding to the reference signal; a correlator to generate a plurality of phase-shifted, reconstructed reference signals; and correlate each of the plurality of phase-shifted, reconstructed reference signals with a reflected signal; and an optimal phase selector to determine an optimal phase based on the correlations and output a distance to a target based on the optimal phase.

Abstract: An example apparatus includes a transducer to receive a reference signal and a reflected signal, the reflected signal being the reference signal after being reflected of a target; a filter to generate a band-pass reference signal and a band-pass reflected signal by filtering (A) reference signal samples associated with the reference signal and (B) reflected signal samples associated with the reflected signal; a correlator to generate a first correlation by correlating the reference signal samples with the reflected signal samples and a second correlation by correlating the band-pass reference signal with the band-pass reflected signal; and a delay estimator to determine a distance to the target based on the first correlation (coarse delay) and the second correlation (fine delay) and output a signal including the distance to the target.

Abstract: Methods and apparatus to determine a distance to a target using coarse and fine delay estimation based on a narrowband transmit signal are disclosed. An example apparatus includes a transducer to receive a reference signal and a reflected signal, the reflected signal being the reference signal after being reflected of a target; a filter to generate a band-pass reference signal and a band-pass reflected signal by filtering (A) reference signal samples associated with the reference signal and (B) reflected signal samples associated with the reflected signal; a correlator to generate a first correlation by correlating the reference signal samples with the reflected signal samples and a second correlation by correlating the band-pass reference signal with the band-pass reflected signal; and a delay estimator to determine a distance to the target based on the first correlation (coarse delay) and the second correlation (fine delay) and output a signal including the distance to the target.

Abstract: Disclosed examples include ultrasonic lens cleaning systems and driver circuits to clean a lens using four or more transducer segments mechanically coupled to the lens, in which the driver circuit provides phase shifted oscillating signals to the transducer segments to generate a mechanical traveling wave rotating around the center axis of the lens to vibrate the lens for improved ultrasonic cleaning.

Abstract: Described examples include an integrated circuit having an analog-to-digital converter operable to receive an input signal derived from a light signal and convert the input signal to a digital received signal, the analog-to-digital converter operable to receive the input signal during at least one window. The integrated circuit further has a receiver operable to receive the digital received signal, the receiver operable to determine a distance estimate of an object from which the light signal is reflected based on the digital received signal. In an example, the window locations are chosen to correspond to the locations of maximum slope in the signal.

Abstract: Methods and apparatus to determine an accurate distance to a target using reference signal interpolation is disclosed. An example apparatus includes an interpolator to receive a first sample of a reference signal and a second sample of a reference signal; and interpolating a reconstructed reference signal sample based on the first and second samples, the reconstructed reference signal corresponding to the reference signal; a correlator to generate a plurality of phase-shifted, reconstructed reference signals; and correlate each of the plurality of phase-shifted, reconstructed reference signals with a reflected signal; and an optimal phase selector to determine an optimal phase based on the correlations and output a distance to a target based on the optimal phase.

Abstract: Methods and apparatus to determine a distance to a target using coarse and fine delay estimation based on a narrowband transmit signal are disclosed. An example apparatus includes a transducer to receive a reference signal and a reflected signal, the reflected signal being the reference signal after being reflected of a target; a filter to generate a band-pass reference signal and a band-pass reflected signal by filtering (A) reference signal samples associated with the reference signal and (B) reflected signal samples associated with the reflected signal; a correlator to generate a first correlation by correlating the reference signal samples with the reflected signal samples and a second correlation by correlating the band-pass reference signal with the band-pass reflected signal; and a delay estimator to determine a distance to the target based on the first correlation (coarse delay) and the second correlation (fine delay) and output a signal including the distance to the target.

Abstract: Disclosed examples include ultrasonic lens cleaning systems and driver circuits to clean a lens using four or more transducer segments mechanically coupled to the lens, in which the driver circuit provides phase shifted oscillating signals to the transducer segments to generate a mechanical traveling wave rotating around the center axis of the lens to vibrate the lens for improved ultrasonic cleaning.

Abstract: In described examples, a spatial light modulator (SLM) receives light from a field of view. The SLM includes a two-dimensional array of picture elements in rows and columns. In response to a transmit scan beam that illuminates the field of view, a portion of the two-dimensional array is impacted by light reflected from a region of interest. The portion of the two-dimensional array is determined. Light is directed from the portion of the two-dimensional array to a photodiode. Light that impacts the two-dimensional array outside the portion is directed away from the photodiode.