In a general aspect, a circuit can include an input circuit configured to receive an input signal, and an amplifier circuit coupled with the input circuit. The amplifier circuit can include an amplifier, and first and second feedback paths. The first feedback path can be from a positive output to a negative input of the amplifier, and the second feedback path can be from a negative output to a positive input of the first amplifier. The circuit can also include a loop circuit 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 current flow into the negative input of the first amplifier. The circuit can also include a control circuit that is configured to enable the loop circuit in response to a magnitude of the input signal exceeding a threshold.

Example circuitry includes a first circuit to provide a low signal; a second circuit to provide a high signal, where the high signal has a greater voltage magnitude than the low signal; and a differential amplifier configured to receive the low signal from the first circuit and the high signal from the second circuit. The differential amplifier is for producing an output voltage that is based on the high signal and the low signal. The example circuitry includes a first measurement circuit to measure the output voltage; a second measurement circuit to measure the low signal at the first circuit; and processing logic to determine a differential measurement based on the output voltage measured by the first measurement circuit, the low signal measured by the second measurement circuit, and calibration values obtained for the circuitry.

A power amplifier provides reduction of click and pop in audio applications. The power amplifier includes a first amplifier and an auxiliary amplifier. The auxiliary amplifier is used to ramp the power amplifier output from ground to an offset voltage to reduce the “click and pop” sound. The first amplifier and the auxiliary amplifier having a shared feedback loop. An output of the first amplifier and an output of the auxiliary amplifier may be switchably coupled to the shared feedback loop. A wave generator controls a switch to couple the first amplifier output or the auxiliary amplifier output to the shared feedback loop.

An apparatus includes a phased array antenna panel and one or more beam former circuits mounted on the phased array antenna panel. The phased array antenna panel generally comprises a plurality of antenna elements. The plurality of antenna elements are generally arranged in one or more groups. Each beam former circuit may be coupled to a respective group of the antenna elements. Each beam former circuit generally comprises a plurality of transceiver channels. Each transceiver channel generally comprises a power amplifier circuit configured, when operating in a transmit mode, to drive a respective one of the antenna elements. The power amplifier circuit generally comprises separate bias and voltage supply inputs providing additional power control.

An auscultatory sound signal acquired by a recording module is coupled through a high-pass filter having a cut-off frequency in the range of 3 to 15 Hz and subsequently filtered with a low-pass filter, and optionally subject to variable-gain amplification under external control—via a USB or wireless interface—of an associated docking system, responsive to the resulting processed auscultatory sound signal. A sound generator in the docking system generates an associated test signal having an integral number of wavelengths for each of a plurality of frequencies. The test signal is applied to a corresponding auscultatory sound-or-vibration sensor to test the integrity thereof. Resulting sound signals recorded by the recording module are analyzed using a Fourier Transform to determine sensor integrity.

An amplifier and a method of outputting a waveform of a music signal capable of outputting a waveform of a music signal exceeding a power supply voltage is provided. An amplifier includes a power supply, an input terminal for a music signal, an amplifying circuit which amplifies the music signal using the power supply, and a jumping-up circuit which is connected to an output end of the amplifying circuit and outputs a waveform exceeding a voltage value of the power supply.

The present invention provides a circuit having a filter with an amplifier circuit for filtering and amplifying an input signal to generate an output signal, wherein a corner frequency of the filter is adjustable to control a settling time of the output signal.

Circuits and methods are disclosed that, in embodiments, may be used for low power memory signal readout. In an embodiment, the circuit comprises a front end stage including an impedance conversion network for receiving a signal and providing voltage or current gain, and a wideband multiplier for receiving an output signal from the impedance conversion network and converting the output signal to differential output signals; and a baseband stage including a voltage mode mixer for receiving the differential output signals from the wideband multiplier and providing voltage gain, and a bandpass filter/amplifier for receiving a mixer output signal from the voltage mode mixer and filtering and amplifying the mixer output signal; and wherein DC voltages of the front-end stage are biased independently of a biasing of DC voltages of the baseband stage.

The disclosure provides a time gain compensation (TGC) circuit. The TGC circuit includes an impedance network. A differential amplifier is coupled to the impedance network. The differential amplifier includes a first input port, a second input port, a first output port and a second output port. A first feedback resistor is coupled between the first input port and the first output port. A second feedback resistor is coupled between the second input port and the second output port. The impedance network provides a fixed impedance to the differential amplifier when a gain of the TGC circuit is changed from a maximum value to a minimum value.

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.