In one implementation, a circuit can include a reference pin and an operational amplifier that can include an output pin, an inverting input pin and a non-inverting input pin. The inverting input pin can be electrically coupled to the output pin via a first impedance and to the reference pin via a second impedance. The non-inverting input pin can be electrically coupled to the reference pin via a third impedance and can be configured to receive a detection signal. The reference pin can be configured to receive a detection reference signal associated with the detection signal.

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.

A bias circuit is adapted for biasing a to-be-biased transconductance cell such that the to-be-biased transconductance cell has a constant transconductance, and includes a converter and a controller. The converter receives first and second current signals, and generates, based on the first and second current signals, a first voltage signal, a second voltage signal and a bias voltage that is for biasing the to-be-biased transconductance cell. The controller receives the first and second voltage signals from the converter, generates the first and second current signals for the converter based on the first and second voltage signals so as to make a magnitude of the first voltage signal equal a magnitude of the second voltage signal.

A system that utilizes an amplified signal is disclosed that includes a plurality of first switches coupled to a plurality of first impedances. A plurality of second switches coupled to a plurality of second impedances. An amplifier having a first input coupled to the plurality of first switches and a second input coupled to the plurality of second switches. A leakage current offset source coupled to the first input of the amplifier, wherein the leakage current offset source cancels a leakage current component of a first current provided from the plurality of first switches to the first input.

This application relates to circuitry for monitoring for instability of an amplifier. The amplifier (100) has a first signal path between an amplifier input (IN.sub.N) and an amplifier output (V.sub.OUT) and a feedback path from the output to form a feedback loop with at least part of the first signal path. A comparator (212) has a first input configured to receive a first signal (IN.sub.N) derived from a first amplifier node which is part of said feedback loop and a second input configured to receive a second signal (IN.sub.P) derived from a second amplifier node which varies with the signal at the amplifier input but does not form part of said feedback loop. The comparator is configured to compare the first signal to the second signal and generate a comparison signal (COMP), wherein in the event of amplifier instability the comparison signal comprises a characteristic indicative of amplifier instability.

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.

An aerosol delivery device is provided. The aerosol delivery device includes terminals configured to connect a power source to the aerosol delivery device and a heating element configured to convert electricity to heat and thereby vaporize components of an aerosol precursor composition. The aerosol delivery device also includes a boost converter configured to step up voltage from the power source to a higher voltage and an inverter configured to convert the higher voltage to a complementary negative voltage. The aerosol delivery device further includes at least one non-inverting amplifier circuit that includes an operational amplifier configured to receive the voltage from the power source as an input voltage, and receive the higher voltage and the complementary negative voltage as supply voltages. The at least one non-inverting amplifier circuit is configured to amplify the input voltage to an output voltage, and provide a continuous output current.

A transimpedance amplifier (TIA) structure includes an input node with a variable inductance component serving to reduce variation in peak amplitude over different gain conditions. According to certain embodiments, an inductor at the TIA input has a first node in communication with a Field Effect Transistor (FET) drain, and a second node in communication with the FET source. A control voltage applied to the FET gate effectively controls the input inductance by adding a variable impedance across the inductor. Under low gain conditions, lowering of inductance afforded by the control voltage applied to the FET reduces voltage peaking. TIAs in accordance with embodiments may be particularly suited to operate over a wide dynamic range to amplify incoming electrical signals received from a photodiode.

A front-end amplifier circuit for receiving a biological signal includes a signal channel. The signal channel amplifies the biological signal to generate a detection current and includes a capacitive-coupled transconductance amplifier. The capacitive-coupled transconductance amplifier amplifies the biological signal with a transconductance gain to generate a first current.