Abstract: A variable current trans-impedance amplifier (TIA) for an ultrasound device is described. The TIA may be coupled to an ultrasonic transducer to amplify an output signal of the ultrasonic transducer representing an ultrasound signal received by the ultrasonic transducer. During acquisition of the ultrasound signal by the ultrasonic transducer, one or more current sources in the TIA may be varied.

Abstract: Circuitry for an ultrasound device is described. The ultrasound device may include a symmetric switch positioned between a pulser and an ultrasound transducer. The pulser may produce bipolar pulses. The symmetric switch may selectively isolate a receiver from the pulser and the ultrasound transducer during a transmit mode of the device, when the bipolar pulses are provided by the pulser to the ultrasound transducer for transmission, and may selectively permit the receiver to receive signals from the ultrasound transducer during a receive mode. The symmetric switch may be provided with a well switch to remove well capacitances in a signal path of the device.

Abstract: A variable current trans-impedance amplifier (TIA) for an ultrasound device is described. The TIA may be coupled to an ultrasonic transducer to amplify an output signal of the ultrasonic transducer representing an ultrasound signal received by the ultrasonic transducer. During acquisition of the ultrasound signal by the ultrasonic transducer, one or more current sources in the TIA may be varied.

Abstract: Aspects of the technology described herein relate to built-in self-testing (BIST) of circuitry (e.g., a pulser or receive circuitry) and/or transducers in an ultrasound device. A BIST circuit may include a transconductance amplifier coupled between a pulser and receive circuitry, a capacitor network coupled between a pulser and receive circuitry, and/or a current source couplable to the input terminal of receive circuitry to which a transducer is also couplable. The collapse voltages of transducers may be characterized using BIST circuitry, and a bias voltage may be applied to the membranes of the transducers based at least in part on their collapse voltages. The capacitances of transducers may also be measured using BIST circuitry and a notification may be generated based on the sets of measurements.

Abstract: Methods and apparatus are described for implementing a coding scheme on ultrasound signals received by a plurality of ultrasonic transducers. The coding, and subsequent decoding, may allow for multiple ultrasonic transducers to be operated in a receive mode simultaneously while still differentiating the contribution of the individual ultrasonic transducers. Improved signal characteristics may result, including improved signal-to-noise ratio (SNR).

Abstract: Circuitry for ultrasound devices is described. A multilevel pulser is described, which can provide bipolar pulses of multiple levels. The multilevel pulser includes a pulsing circuit and pulser and feedback circuit. Symmetric switches are also described. The symmetric switches can be positioned as inputs to ultrasound receiving circuitry to block signals from the receiving circuitry.

Abstract: A variable-current trans-impedance amplifier (TIA) for an ultrasound device is described. The TIA may be coupled to an ultrasonic transducer to amplify an output signal of the ultrasonic transducer representing an ultrasound signal received by the ultrasonic transducer. During acquisition of the ultrasound signal by the ultrasonic transducer, one or more current sources in the TIA may be varied. The variable-current trans-impedance amplifier may include multiple stages, including a first stage having N-P transistor pairs configured to receive an input signal and produce a single-ended amplified signal.

Abstract: Circuitry for ultrasound devices is described. A multi-level pulser is described, which can support time-domain and spatial apodization. The multi-level pulser may be controlled through a software-defined waveform generator. In response to the execution of a computer code, the waveform generator may access master segments from a memory, and generate a stream of packets directed to pulsing circuits. The stream of packets may be serialized. A plurality of decoding circuits may modulate the streams of packets to obtain spatial apodization.

Abstract: An ultrasound device, including a profile generator, an encoder configured to receive a profile signal from the profile generator, and an attenuator configured to receive a signal representing an output of an ultrasound sensor and coupled to the encoder to receive a control signal from the encoder, the attenuator including a plurality of attenuator stages, the attenuator configured to produce an output signal that is an attenuated version of the input signal.

Abstract: Ultrasound devices are disclosed. The ultrasound devices have an elevational dimension. Different percentages of the aperture of the ultrasound device corresponding to different percentages of the elevational dimension are utilized in different applications. The resolution of imagine may be adjusted in connection with usage of different percentages of the aperture.

Abstract: Aspects of the technology described herein relate to control circuitry configured to turn on and off the ADC driver. In some embodiments, the control circuitry is configured to turn on and off the ADC driver in synchronization with sampling activity of an ADC, in particular based on when an ADC is sampling. The control circuitry may be configured to turn on the ADC driver during the hold phase of the ADC a time period before the track phase and to turn off the ADC driver during the hold phase a time period after the track phase. In some embodiments, the control circuitry is configured to control a duty cycle of the ADC driver turning on and off. In some embodiments, the control circuitry is configured to control a ratio between an off current and an on current in the ADC driver.

Abstract: An ultrasound circuit comprising a trans-impedance amplifier (TIA) with built-in time gain compensation functionality is described. The TIA is coupled to an ultrasonic transducer to amplify an electrical signal generated by the ultrasonic transducer in response to receiving an ultrasound signal. The TIA is, in some cases, followed by further analog and digital processing circuitry.

Abstract: Aspects of the technology described herein related to an ultrasound processing unit (UPU) including gray-coding circuitry configured to convert standard binary-coded digital ultrasound signals to gray-coded digital ultrasound signals and gray-decoding circuitry coupled to the gray-coding circuitry and configured to convert the gray-coded digital ultrasound signals to standard binary-coded digital ultrasound signals. The UPU may include an analog portion, a digital portion, and a data bus configured to route the gray-coded digital ultrasound signals from the analog portion to the digital portion subsequent to converting the standard binary-coded digital ultrasound signals to the gray-coded digital ultrasound signals. The analog portion may include multiple analog front-ends (AFEs), the gray-coding circuitry, and an analog-to-digital converter. The digital portion may include the gray-decoding circuitry. A data bus from one AFE may pass over another AFE.

Abstract: Aspects of the technology described herein relate to an ultrasound device including a first die that includes an ultrasonic transducer, a first application-specific integrated circuit (ASIC) that is bonded to the first die and includes a pulser, and a second ASIC in communication with the second ASIC that includes integrated digital receive circuitry. In some embodiments, the first ASIC may be bonded to the second ASIC and the second ASIC may include analog processing circuitry and an analog-to-digital converter. In such embodiments, the second ASIC may include a through-silicon via (TSV) facilitating communication between the first ASIC and the second ASIC. In some embodiments, SERDES circuitry facilitates communication between the first ASIC and the second ASIC and the first ASIC includes analog processing circuitry and an analog-to-digital converter. In some embodiments, the technology node of the first ASIC is different from the technology node of the second ASIC.

Abstract: Aspects of the technology described herein relate to ultrasound circuits that employ a differential ultrasonic transducer element, such as a differential micromachined ultrasonic transducer (MUT) element. The differential ultrasonic transducer element may be coupled to an integrated circuit that is configured to operate the differential ultrasonic transducer element in one or more modes of operation, such as a differential receive mode, a differential transmit mode, a single-ended receive mode, and a single-ended transmit mode.

Abstract: Aspects of the technology described herein relate to an ultrasound device including a first die that includes an ultrasonic transducer, a first application-specific integrated circuit (ASIC) that is bonded to the first die and includes a pulser, and a second ASIC in communication with the second ASIC that includes integrated digital receive circuitry. In some embodiments, the first ASIC may be bonded to the second ASIC and the second ASIC may include analog processing circuitry and an analog-to-digital converter. In such embodiments, the second ASIC may include a through-silicon via (TSV) facilitating communication between the first ASIC and the second ASIC. In some embodiments, SERDES circuitry facilitates communication between the first ASIC and the second ASIC and the first ASIC includes analog processing circuitry and an analog-to-digital converter. In some embodiments, the technology node of the first ASIC is different from the technology node of the second ASIC.

Abstract: Circuitry for ultrasound devices is described. A multilevel pulser is described, which can provide bipolar pulses of multiple levels. The multilevel pulser includes a pulsing circuit and pulser and feedback circuit. Symmetric switches are also described. The symmetric switches can be positioned as inputs to ultrasound receiving circuitry to block signals from the receiving circuitry.

Abstract: A time gain compensation (TGC) circuit for an ultrasound device includes a first amplifier having an integrating capacitor and a control circuit configured to generate a TGC control signal that controls an integration time of the integrating capacitor, thereby controlling a gain of the first amplifier. The integration time is an amount of time an input signal is coupled to the first amplifier before the input signal is isolated from the first amplifier.

Abstract: Methods and apparatus are described for implementing a coding scheme on ultrasound signals received by a plurality of ultrasonic transducers. The coding, and subsequent decoding, may allow for multiple ultrasonic transducers to be operated in a receive mode simultaneously while still differentiating the contribution of the individual ultrasonic transducers. Improved signal characteristics may result, including improved signal-to-noise ratio (SNR).

Abstract: An ultrasound device, including a profile generator, an encoder configured to receive a profile signal from the profile generator, and an attenuator configured to receive a signal representing an output of an ultrasound sensor and coupled to the encoder to receive a control signal from the encoder, the attenuator including a plurality of attenuator stages, the attenuator configured to produce an output signal that is an attenuated version of the input signal.