An amplifier includes an amplification circuit including an input circuit receiving an input signal and configured to output an output signal by amplifying the input signal; and an offset cancelling circuit configured to cancel offset by controlling the input circuit according to activation control signal and offset control signal, wherein the offset cancelling circuit cancels the offset according to the offset control signal after the activation control signal is activated.

Systems and methods for calibrating a wireless power transmitter is described. A wireless power transmitter can include a controller and an amplifier module. The amplifier module can include an amplifier configured to amplify a voltage converted from a current proportional to power consumed by a wireless power transmitter, and a circuit connected to the amplifier. The circuit can be configured to receive a control signal from the controller. The circuit can be further configured to perform time division multiplexing on an output of the amplifier according to the control signal. A time division multiplexed output of the amplifier can include calibration data of the amplifier. The amplifier can be configured to output the time division multiplexed output to the controller.

The disclosure presents a method and an amplifier system for minimizing variation in an acoustical signal caused by variation in gain of an amplifier, comprising a battery for providing a supply voltage to the amplifier, a digital signal processor for providing the acoustical signal to the amplifier, a controller unit receiving an enablement signal when the supply voltage is in an offset mode, and based on the enablement signal requesting a measured voltage during a time period, and a first analog-to-digital converter configured for measuring the supply voltage to the amplifier when receiving the request from the controller unit or the first analog-to-digital converter is configured for measuring the supply voltage to the amplifier continuously, and where variations in the measured voltage relates to variations in the supply voltage during the time period. Furthermore, the controller unit is configured to predict offset modes (i.e. changes) in the supply voltage based on the enablement signals and a fitting of the measured voltages, and wherein the controller unit is configured to generate a compensating signal based on the fitting and transmit the compensating signal to the digital signal processor, the digital signal processor is then configured to minimize variation in the acoustical signal at the output of the amplifier by compensating the variation in gain of the amplifier based on the compensating signal.

Systems, methods, and computer program product embodiments are disclosed for performing electrophysiology (EP) signal processing. An embodiment includes an electrocardiogram (ECG) circuit board configured to process an ECG signal. The embodiment further includes a plurality of intracardiac (IC) circuit boards, each configured to process a corresponding IC signal. The ECG circuit board and the plurality of IC circuit boards share substantially a same circuit configuration and components. The ECG circuit board further processes the ECG signal using substantially a same path as each IC circuit board uses to process its corresponding IC signal.

An internal voltage offset between a positive input and a negative input of a first operational amplifier is compensated. The negative input and the positive input of the first operational amplifier are coupled at the same voltage level. A comparison current generated at an output of the first operational amplifier has a sign that is representative of a sign of the internal voltage offset. The output of the first operational amplifier is biased to a threshold voltage using a current-to-voltage converter. A control voltage is generated from a sum of the threshold voltage and a voltage conversion of the comparison current. Compensation for the internal voltage offset between the positive and negative inputs of the first operational amplifier is made dependent on the control voltage.

A preamplifier circuit comprises a first pair of transistors and a second pair of transistors having current flow paths therethrough coupled at first and second output nodes and providing first and second current flow lines intermediate a supply node and ground. The two pairs of transistors comprise: first and second input transistors located intermediate the outputs nodes and one of the supply node and ground providing respective input nodes, first and second load transistors intermediate the output nodes and the other of the supply node and ground. The load transistors have control terminals capacitively coupled to the other of the supply node and ground and a reset switch arrangement is provided periodically activatable to short the first output node, the second output node as well as the control terminals of the first load transistor and the second load transistor.

A semiconductor device includes an equalizer for receiving a first signal and outputting a second signal that has been adjusted to compensate for attenuation of the first signal. A filter is connected to the output terminal of the equalizer. A cancellation circuit operates to cancel a DC offset in the output of the equalizer. A processing circuit is configured to control the cancellation circuit to cancel the DC offset according to an output from the filter. The processing circuit sets a time constant for the filter to a first value to permit the cancellation circuit to cancel the DC offset when the equalizer is in a first state, and then sets the time constant to a second value when the equalizer is set to a second state to permit the cancellation circuit to cancel the DC offset when the equalizer is in the second state.

Circuitry comprising: a voltage monitoring path; a current monitoring path; a reference element of a predefined impedance; and processing circuitry, wherein in operation of the circuitry in a calibration mode of operation: the voltage monitoring path is operative to output a signal indicative of a voltage across the reference element in response to a reference signal applied to the reference element; the current monitoring path is operative to output a signal indicative of a current through the reference element in response to the reference signal; and the processing circuitry is operative to: receive the signal indicative of the voltage across the reference element and the signal indicative of the current through the reference element; generate an estimate of an impedance of the reference element; and determine a compensation parameter for an element of the circuitry for compensating for a difference between the estimate of the impedance and the predefined impedance of the reference element.

A method may include receiving, by a calibration circuit, an output of a subsystem comprising the sensor and the analog front end. The method may further include separating the output individually into the sensor offset and the amplifier offset by using inherent properties of separate frequency ranges for the sensor offset and the amplifier offset. The method may also include calibrating, by the calibration circuit, the sensor offset by determining a first calibration value for the sensor offset such that the output approximates zero during an idle-channel condition. The method may additionally include calibrating, by the calibration circuit, the amplifier offset by determining a second calibration value for the amplifier offset such that the output approximates zero during the idle-channel condition.

A chopper circuit (100) for a multipath chopper amplifier (201) is described. The chopper circuit (100) comprises a first chopper device (110) in a first circuit path (111), wherein the first chopper device (110) is configured to be controlled by a first clock signal (315), which has a first frequency; and a second chopper device (120) in a second circuit path (121), parallel to the first circuit path (111), wherein the second chopper device (120) is configured to be controlled by a second clock signal (325), which has a second frequency, wherein the first frequency is greater than the second frequency. Furthermore, a corresponding method of chopping an input signal (102) is described.