In an embodiment, a differential buffer may include a first input stage that compares a non-inverting portion of an input signal alternately to a non-inverting portion of an output and to an inverting portion of the output. Another embodiment of the differential buffer may also include a second input stage that compares the inverting portion of the input signal alternately to the inverting portion of the output signal and to the non-inverting portion of the output signal. Other embodiments of the differential buffer may include a feedback chopper switch that transfers the non-inverting portion of the output signal and the inverting portion of the output signal to the first input stage and to the second input stage.

A method includes receiving, by a regulating circuit, a battery feedback parameter and producing, by an operational transconductance amplifier, a first output current at an output terminal based on the battery feedback parameter and a battery current regulation voltage. The method also includes producing, by a current source, a second current at the output terminal based on the battery feedback parameter and a reference voltage.

This application relates to amplifier circuitry for amplifying an input signal from a MEMS capacitive sensor. The amplifier circuitry includes a first amplifier for receiving the input signal (V.sub.INP) and outputting a first output signal (V.sub.OUTP) based on the input signal. A second amplifier is configured to output a second output signal (V.sub.OUTN) which varies inversely with the first output signal. The first and second amplifier outputs are connected via first and second impedances so that a voltage at a common-mode node is equal to a common-mode voltage of the first and second output signals. The second amplifier has an input stage having an input terminal connected to a first reference voltage (V.sub.R1) and a feedback terminal connected to the common-mode node. The second amplifier also has an output stage connected between an output terminal of the input stage and the second amplifier output.

The present disclosure relates to a semiconductor device and a cell potential measuring apparatus capable of amplifying and reading a potential of solution with high accuracy. A reading electrode reads the potential of the solution. A differential amplifier includes a current mirror circuit. The reading electrode is connected to a first input terminal of the differential amplifier which is connected to a gate of a first input transistor connected to a diode-connected pMOS transistor of the current mirror circuit. An output terminal of the differential amplifier is connected to a second input terminal of the differential amplifier, which is connected to a gate of a second input transistor connected to a pMOS transistor of the current mirror circuit which is not diode-connected, via a capacitor. For example, the present disclosure is applied to the cell potential measuring apparatus and the like.

A spectrometer engine and an adjustment method thereof are provided. The spectrometer engine includes a connector, a light sensor, a variable gain amplifier, a variable reference voltage generation circuit, an analog-to-digital converter and a control circuit. The light sensor senses a light to be measured coming from an object to be measured to generate a sensing signal. The variable gain amplifier amplifies the sensing signal according to a first setting parameter to generate an amplified signal. The variable reference voltage generation circuit provides a reference voltage according to a second setting parameter. The analog-to-digital converter converts the amplified signal to a digital signal according to the reference voltage. The control circuit reads the digital signal and adjusts at least one of the first to third setting parameters according to the digital signal for the spectrometer engine to measure the object to be measured again to generate another digital signal.

A signal measuring apparatus and method is provided. The signal measuring apparatus inputs a reduced voltage signal to an input end of an amplifier by resetting a voltage signal, which is acquired by applying a known current signal to a target object, using a common mode voltage at least once during one period of a current signal. The signal measuring apparatus acquires a digital signal corresponding to an object impedance change by converting an output of the amplifier.

Transimpedance amplifiers with feedforward current are provided herein. In certain embodiments, an amplifier system includes a transimpedance amplifier that amplifies an input current received at an input to generate an output voltage at an output. The amplifier system further includes a controllable current source that is coupled to the output of the transimpedance amplifier, and operable to provide a feedforward current that changes in relation to the input current of the transimpedance amplifier. By providing a feedforward current in this manner, gain and speed performance of the transimpedance amplifier is enhanced.

A gain amplifier of a sensing circuit for sensing degradation of an OLED display panel, the gain amplifier comprising: an operation amplifier; and a plurality of gain amplifier cells sequentially coupled to the operation amplifier. Each of the gain amplifier cells comprises a plurality of capacitors each placed between two internal nodes of the gain amplifier cell, excluding a ground node, such that a voltage gain of the gain amplifier and a DC offset of the gain amplifier are determined according to capacitances of the capacitors without considering parasitic capacitance.

A preamplifier comprises an input stage and a capacitive coupling stage. The input stage is arranged to receive a differential signal from a magnetic resistor which indicates a magnetic field sensed on a magnetic disk of a hard disk drive (HDD) when the preamplifier is powered on from an off state. The capacitive coupling stage has an input arranged to receive the differential signal from the input stage, a filter comprising a first resistor, a second resistor, a first capacitor, a second capacitor, and switches arranged in parallel with respective resistors, where the switches are closed when the preamplifier is powered on from the off state to an on state. A switch control is arranged to determine that an offset of the differential signal has settled and open the switches based on the determination.

A common source preamplifier for a MEMS capacitive sensor is disclosed. The preamplifier is a single-stage amplifier employing negative feedback. The preamplifier provides stable gain independent of temperature and at the same time provides effective buffering for a subsequent stage. Further, the preamplifier may be configured to provide different values of gain. Furthermore, the preamplifier has lower noise and consumes lesser area and lesser power than prior art.