In a general aspect, a circuit can include an amplifier circuit including a first amplifier, a first feedback path, and a second feedback path. The first feedback path can provide a feedback path from a positive output of the first amplifier to a negative input of the first amplifier. The second feedback path can provide a feedback path from a negative output of the first amplifier to a positive input of the first amplifier, The circuit can also include a loop circuit including a second amplifier, The loop circuit can be configured to provide a local feedback loop for the first amplifier and configured to control current flow into the positive input of the first amplifier and into the negative input of the first amplifier.

An amplifier circuitry includes a current source circuit, a voltage regulator circuit, and an amplifier. The current source circuit generates a first bias current. The voltage regulator circuit regulates a reference voltage to generate a supply voltage. The voltage regulator circuit includes a first and a second compensation resistors, the first and the second compensation resistors are configured to generate the reference voltage according to a reference a second bias currents, and a first ratio is present between the first and the second biasing currents. The amplifier includes first load resistors which are configured to generate a first common-mode output signal based on the supply voltage and the first bias current. The second ratio is present between the second compensation resistor and one of the first load resistors, and the first and the second ratios are arranged to compensate the first common-mode output signal.

A magnetic sensor circuit includes a vertical-magnetic-field sensor, a horizontal-magnetic-field sensor, a control circuit controlling a first measurement mode and a second measurement mode through switching, a first feedback circuit configuring a feedback loop of a first operational amplifier, a second feedback circuit configuring a feedback loop of a second operational amplifier, a connecting circuit, and at least any one of a first switch switching an impedance of the first feedback circuit, a second switch switching an impedance of the second feedback circuit, and a third switch switching an impedance of the connecting circuit those which controlled by the control circuit. The magnetic sensor circuit detects magnetic fields in nearly the same two-axial sensitivity without using a magnetic converging plate while reducing an occupation area of the amplifier circuit.

Various embodiments of the present technology may comprise methods and apparatus for actuator control. The methods and apparatus may comprise various circuits and/or systems to detect an induced voltage and various signal processing functions to utilize the induced voltage to control the actuator. The apparatus for actuator control may comprise an induced voltage detection circuit and adjust the actuator position according to the detected induced voltage.

A power amplifier includes a two-dimensional matrix of NM active cells formed by stacking main terminals of multiple active cells in series. The stacks are coupled in parallel to form the two-dimensional matrix. The power amplifier includes a driver structure to coordinate the driving of the active cells so that the effective output power of the two-dimensional matrix is approximately NM the output power of each of the active cells.

Circuitry for voltage-to-current conversion, and in particular to differential voltage-to-current conversion circuitry. Such circuitry is operable to receive a differential voltage input signal and output a corresponding differential current signal. First and second controllable current sinks are connected to first and second load nodes of the circuitry so as to draw corresponding sink currents from those nodes.

A sigma-delta modulator and method for converting an input voltage such as an analog signal into a digital signal is presented. The modulator may be used as an analog-to-digital converter (ADC). The modulator has a plurality of bias transistors with at least one p-type transistor and at least one n-type transistor. The modulator receives a bias voltage, wherein each bias transistor receives the same bias voltage. This sigma-delta modulator results in reduced power consumption.

A wireless transceiver device includes an operation amplification circuit, a transmitter circuit, a receiver circuit, and a transceiver control circuit. The operation amplification circuit, according to a rate parameter and a filtering parameter, filters and amplifies an input signal and outputs a processed signal. The transmitter circuit selectively uses a first ratio or second ratio as the amplification parameter, converts an input signal into an analog signal, inputs the analog signal into the operation amplification circuit, mixes the processed signal with a local oscillating frequency and then output an output signal. The receiver circuit mixes an external signal with another local oscillating frequency, inputs the mixed signal into the operation amplification circuit, and converts the processed signal into a digital signal. The transceiver control circuit selectively and electrically connects the operation amplification circuit with the transmitter circuit or the receiver circuit.

The present disclosure relates to a current detecting apparatus using an operational amplifier and a method thereof. In accordance with an aspect of the present disclosure, there is provided a current detecting apparatus of a conductor including: a shunt resistor connected to the conductor; an operational amplifier connected to the shunt resistor; a first resistor connected between the shunt resistor and a first input terminal of the operational amplifier; a second resistor connected between the shunt resistor and a second input terminal of the operational amplifier; a third resistor connected between a ground and the first input terminal of the operational amplifier; and a fourth resistor connected between the ground and the second input terminal of the operational amplifier.

A wireless transceiver device includes an operation amplification circuit, a transmitter circuit, a receiver circuit, and a transceiver control circuit. The operation amplification circuit, according to a rate parameter and a filtering parameter, filters and amplifies an input signal and outputs a processed signal. The transmitter circuit selectively uses a first ratio or second ratio as the amplification parameter, converts an input signal into an analog signal, inputs the analog signal into the operation amplification circuit, mixes the processed signal with a local oscillating frequency and then output an output signal. The receiver circuit mixes an external signal with another local oscillating frequency, inputs the mixed signal into the operation amplification circuit, and converts the processed signal into a digital signal. The transceiver control circuit selectively and electrically connects the operation amplification circuit with the transmitter circuit or the receiver circuit.