An input buffer circuit includes an input differential amplifier unit, a differential amplifier stage, and a buffer. The input differential amplifier unit has input terminals and at least one output terminal, wherein at least two of the input terminals of the input differential amplifier unit are configured to be capacitively coupled respectively so as to provide at least one pair of signal paths for a first input signal and a second input signal of a differential input signal. The differential amplifier stage, coupled to the input differential amplifier unit, has first and second differential input terminals, and a corresponding output terminal, wherein the first and second differential input terminals are capable of being coupled to the first input signal and the second input signal respectively. The buffer, coupled to the output terminal of the differential amplifier stage, is used for outputting an output single-ended signal.

A signal amplification method includes receiving, from a capacitive sensor, a first input signal by a first control terminal of a first transistor, and a second input signal by a first control terminal of a second transistor. The method also includes producing a first output signal, including amplifying a first signal at a first load path terminal of the first transistor using a first inverting amplifier having an output coupled to a resistance network, and producing a second output signal, including amplifying a second signal at a first load path terminal of the second transistor using a second inverting amplifier having an output coupled to the resistance network. The method also includes feeding back the first and second output signal to a second load path terminal of the first transistor and to a second load path terminal of the second transistor via the resistance network according to a pre-determined fraction.

A Class-D amplifier includes a plurality of power rails, a quantizer, and a driver stage. The quantizer and the driver stage have a combined gain. For each power rail of the plurality of power rails, the Class-D amplifier senses a voltage value for the power rail and determines a ramp amplitude based on the sensed voltage value. The Class-D amplifier concurrently switches from the driver stage using a first power rail to a second power rail of the plurality of power rails and switches from the quantizer using the ramp amplitude associated with the first power rail to using the ramp amplitude associated with the second power rail so that the combined gain is constant.

A high CMRR neural signal amplifier is configured for supply rail common mode feedback (SR-CMFB) whereby a set of CMFB signals is provided to supply rails of front end LNAs. High CMRR is maintained through buffering outputs of front end signal LNAs and a reference LNA coupled to signal and reference inputs of second stage amplifiers, respectively; and buffering the reference LNA output using an active/guard buffer pair, whereby across a plurality of distinct multiplexing time intervals, during each multiplexing time interval one buffer of the pair functions as an active buffer that drives second stage amplifier reference inputs corresponding to second stage amplifier outputs being multiplexed to a set of multiplexor outputs, and the other buffer of the pair functions as a guard buffer coupled to other second stage amplifier reference inputs corresponding to second stage amplifier outputs not being multiplexed to the set of multiplexor outputs.

Current monitoring techniques are included in an electronic system that provides power to a load from a power output stage that supplies power to a load. Multiple current control devices form the power output stage in series with multiple sense resistors that provide corresponding sense voltages indicative of current provided through the multiple current control devices to the load in the same or different time intervals. A calibration control circuit controls injection of current through the multiple sense resistors individually and measures the corresponding sense voltages generated by the current to determine resistance values of the multiple sense resistors. A correction subsystem computes a first ratio of a first resistance to a second resistance and a second ratio of a third resistance to a fourth resistance of the multiple sense resistors, and controls compensation for a difference between the first ratio and the second ratio to remove the measurement error.

A preamplifier amplifies signals input to first and second input terminals. A first switching circuit receives first and second input signals and outputs those to the first and second input terminals. A switched capacitor circuit samples two signals amplified by the preamplifier. Differential signals sampled by the switched capacitor circuit are respectively input to third and fourth input terminals of an integration circuit, and the integration circuit outputs differential signals obtained by those input signals to first and second output terminals. A second switching circuit switches a connection relationship between the switched capacitor circuit and the integration circuit. Each time the cycle changes, the first and second switching circuits switch the connection relationships to cause the signals amplified by the preamplifier to be sampled by double correlation sampling.

A magnetic resonance wireless power transmission device capable of adjusting resonance frequency is disclosed. A wireless power transmission device according to an embodiment of the present invention comprises: a power amplifier for amplifying a wireless power signal using a driving frequency signal; a resonator for configuring a resonance tank and wirelessly transmitting, through magnetic resonance, the wireless power signal output from the power amplifier using a resonance frequency of the resonance tank; and a resonance control unit for controlling a duty ratio using a frequency applied to the resonator or a frequency signal generated by the resonator and adjusting the resonance frequency of the resonator.

An isolation amplifier of an embodiment includes: a primary circuit including an encoder configured to encode an input signal and output the encoded input signal and an anomaly detection circuit configured to detect anomaly having occurred to the input signal and generate a detection signal; an isolation unit configured to insulate the primary circuit from a secondary circuit; an output circuit configured to generate an output signal corresponding to the input signal; and an anomaly-input sensing-output circuit configured to generate an output signal from the secondary circuit by changing the output signal from the output circuit based on the detection signal.

In one form, a signal chain circuit includes a signal chain processing circuit between an input for receiving a differential input signal having a first common-mode voltage, and an output for providing a differential output signal having a second, different common-mode voltage. It includes an amplifier with a differential output stage coupled to a differential input stage and having positive and negative output terminals forming its output, and positive and negative feedback terminals. The differential output stage provides a first voltage drop between the positive output terminal and the positive feedback terminal, and a second voltage drop between the negative output terminal and the negative feedback terminal. The common-mode feedback circuit regulates a common-mode voltage between the positive and negative feedback terminals to the second common-mode voltage. In another form, an analog-to-digital converter includes a range extending logic circuit to extend the range of a ring oscillator based analog-to-digital converter.

A detection device includes a driving circuit which drives a vibrator, and a detection circuit which detects a desired signal. The driving circuit includes a current-voltage conversion circuit which receives a feedback signal, and performs a current-voltage conversion, a drive signal output circuit which amplifies an input voltage signal after being subjected to the current-voltage conversion, and outputs a drive signal of a sine wave, and a gain control circuit which controls a gain of amplification of the drive signal in the drive signal output circuit. When a resistance for a current-voltage conversion is set to RI, the gain of the amplification of the drive signal in the drive signal output circuit is set to K, and an equivalent series resistance in a fundamental wave mode of the vibrator is set to R, the gain control circuit performs a gain control such that K×RI=R is satisfied.