An electroactive material actuator and sensor is actuated with an actuation signal having an activation period for charging the actuator and a de-activation period for discharging the actuator. A parallel resistance of the actuator is determined by sensing a steady state current during the activation period and a series capacitance of the actuator is determined based on a charge flow during charging of the actuator at the beginning of the activation period. A series resistance is obtained by controlling a current through the actuator with an oscillating profile so that a phase relationship of the actuator between current and voltage can be measured. An oscillating current sink is used to enable circuit component measurements, which implement sensing functionality.

A data acquisition system (DAS) for processing an input signal from a resistive sensor (e.g., Hall effect sensor) includes a sensor signal path that digitizes the input signal. An input impedance of the sensor signal path attenuates the input signal. A gain error corrector applies a gain error correction factor in a digital domain of the DAS to the digitized input signal to compensate for a loading effect to the resistive sensor. The sensor signal path includes an inverting amplifier that provides low distortion for the input signal and an ADC (e.g., delta-sigma, SAR, pipelined, auxiliary) that digitizes the input signal. A sensor characterization path digitizes the sensor resistance which the gain error corrector uses, along with the inverting amplifier input impedance, to calculate the gain error correction factor.

The present invention provides a circuitry of a biopotential acquisition system comprising an input node, an ETI transmitter and an ADC. The input node is coupled to an electrode of the biopotential acquisition system, and the electrode is used to be in contact with a human body. The ETI transmitter is configured to generate a transmitter signal to the input node. The ADC is coupled to the input node, and is configured to process an input signal from the input node to generate a digital signal, wherein each of the input signal and the digital signal comprises components of an ECG signal and an ETI signal.

A current sensing topology uses an amplifier with capacitively coupled inputs in feedback to sense the input offset of the amplifier, which can be compensated for during measurement. The amplifier with capacitively coupled inputs in feedback is used to: operate the amplifier in a region where the input common-mode specifications are relaxed, so that the feedback loop gain and/or bandwidth is higher; operate the sensor from the converter input voltage by employing high-PSRR (power supply rejection ratio) regulators to create a local, clean supply voltage, causing less disruption to the power grid in the switch area; sample the difference between the input voltage and the controller supply, and recreate that between the drain voltages of the power and replica switches; and compensate for power delivery network related (PDN-related) changes in the input voltage during current sensing.

A data acquisition system (DAS) for processing an input signal from a resistive sensor (e.g., Hall effect sensor) includes a sensor signal path that digitizes the input signal. An input impedance of the sensor signal path attenuates the input signal. A gain error corrector applies a gain error correction factor in a digital domain of the DAS to the digitized input signal to compensate for a loading effect to the resistive sensor. The sensor signal path includes an inverting amplifier that provides low distortion for the input signal and an ADC (e.g., delta-sigma, SAR, pipelined, auxiliary) that digitizes the input signal. A sensor characterization path digitizes the sensor resistance which the gain error corrector uses, along with the inverting amplifier input impedance, to calculate the gain error correction factor.

An apparatus for detecting a wiring short in a substrate includes a voltage source configured to apply a rising or falling measurement voltage to a first wiring of a substrate, a plurality of electrodes including first and second electrode elements capacitively coupled to the first and second wirings of the substrate, respectively, a sensing circuit configured to generate an output voltage based on a voltage or a current between the first and second electrode elements, and a processor configured to determine whether a short circuit connection having a resistance value greater than a reference resistance value is present between the first and second wirings based on a change rate of the output voltage after application of the measurement voltage. Methods for detecting wiring shorts in the substrate are further provided.

A current sensor includes a conductor, and first and second magnetic sensing elements. The first magnetic sensing element is positioned such that the magnetic field component in the second direction of the magnetic field generated by the measurement target current flowing through the first conductor portion is opposite in polarity to the magnetic field component in the second direction of the magnetic field generated by the measurement target current flowing through the third conductor portion. The second magnetic sensing element is positioned such that the magnetic field component in the second direction of the magnetic field generated by the measurement target current flowing through the second conductor portion is opposite in polarity to the magnetic field component in the second direction of the magnetic field generated by the measurement target current flowing through the third conductor portion.

According to certain aspects, a predictive tracking scheme is provided for sampling inductor currents in a digital PWM controller used for high-bandwidth voltage regulation. In one or more embodiments, the predicted current derived from the PWM waveform is fed forward to the current sense ADC in order to reduce the required conversion range. These and other embodiments only need to convert a few of the LSB of the ADC in order to correct the largest error expected in the synthesizer.

Techniques are provided to facilitate current sensing recovery for imaging systems and methods. In one example, a device includes a detector configured to detect electromagnetic radiation and generate a detection signal based on the detected electromagnetic radiation. The device further includes a current sensing circuit configured to provide, based on the detection signal, a first signal. The device further includes a signal generator configured to provide a second signal to adjust a bandwidth associated with the current sensing circuit. The device further includes an imaging integration circuit configured to generate an image of at least a portion of a scene based at least in part on the first signal. Related methods and systems are also provided.

A current sensor including a voltage generation circuit and a voltage integration circuit is provided. The voltage generation circuit is configured to generate a first voltage according to a current to be sensed. The voltage integration circuit is coupled to the voltage generation circuit and configured to receive the first voltage and a second voltage to generate an output voltage. The voltage integration circuit includes a first amplifier, a second amplifier and a first capacitor. The first amplifier is configured to receive the first voltage and the second voltage to generate a third voltage. The second amplifier is coupled to the first amplifier and configured to receive the third voltage to generate the output voltage. The first capacitor is coupled between an output terminal of the voltage generation circuit and an output terminal of the first amplifier and configured to reduce a voltage difference between the first voltage and the second voltage.