A device is disclosed. The device includes an operational amplifier, an output circuit and a first feedback circuit. The operational amplifier includes an input terminal that is configured to receive a feedback signal. The output circuit is coupled to an output terminal of the operational amplifier and is configured to generate an output signal in response to an output of the operational amplifier. The first feedback circuit is coupled to the output circuit and is configured to couple at least one first ripple signal in the output signal to the input terminal of the operational amplifier that is configured to receive the feedback signal, for adjusting the output signal. A method also is disclosed herein.

A transceiver includes a first common T-coil circuit coupled to a first input-output pin of the transceiver, a termination impedance coupled to the first common T-coil circuit and configured to match an impedance of a transmission line coupled to the first common T-coil circuit, an amplifier configured to receive an input signal from the first input-output pin through the first common T-coil circuit based on a receive enable signal, and a first transmission buffer configured to transmit an output signal to the first input-output pin through the first common T-coil circuit based on a transmit enable signal.

A transceiver includes a first common T-coil circuit coupled to a first input-output pin of the transceiver, a termination impedance coupled to the first common T-coil circuit and configured to match an impedance of a transmission line coupled to the first common T-coil circuit, an amplifier configured to receive an input signal from the first input-output pin through the first common T-coil circuit based on a receive enable signal, and a first transmission buffer configured to transmit an output signal to the first input-output pin through the first common T-coil circuit based on a transmit enable signal.

An industrial process field device includes an active component, a switch, a switch monitor, and a controller. The active component may be a sensor configured to sense a process parameter, or a control device configured to control a process of the industrial process. The switch is electrically coupled to first and second terminals. The switch monitor is configured to detect an open or closed state of the switch, and generate a first state output, a second state output, or a chattering state output. An anti-chatter circuit outputs a chatter stabilized state output based on the chattering state output. The controller is configured to set the switch in the open or closed state, and generate a notification based on any one of the first and second state outputs and the chatter stabilized state output that indicates at least one of the current state and a condition of the switch.

A fully-differential two-stage operational amplifier circuit is provided, and it includes a first-stage amplification circuit, a second-stage amplification circuit, a common-mode signal acquisition circuit, a common-mode feedback circuit and a bias circuit. The first-stage amplification circuit has a telescopic structure and receives differential input signals IN.sub.P and IN.sub.N. The second-stage amplification circuit has a common-source structure and outputs differential output signals OUT.sub.P and OUT.sub.N. The common-mode signal acquisition circuit receives differential output signals, and outputs an operational amplifier output common-mode signal V.sub.CMO. The common-mode feedback circuit outputs common-mode feedback signals VB.sub.1 and VB.sub.2 to the first-stage amplifier circuit and the second-stage amplifier circuit respectively; The bias circuit outputs a bias voltage VB.sub.3 to the first-stage amplifier circuit, and outputs bias voltages VB.sub.4 and VB.sub.5 to the first-stage amplifier circuit respectively.

A power detector circuit that rejects the common mode portion of a differential signal is disclosed. The circuit includes a differential input having first and second input nodes. Differential and common mode circuit paths are coupled to the differential input. The common mode circuit path includes first and second capacitors coupled to respective first terminals of first and second input nodes of the differential input. The second terminal of each of the first and second capacitors is coupled to a gate terminal of a first bias transistor. The common mode circuit path is configured to reject a common mode portion of a differential input signal provided to the differential input such that a differential output signal is indicative of an amount of power of a differential portion of the differential input signal.

Low noise amplifiers (LNAs) are disclosed herein. In certain embodiments, an LNA includes an input balun configured to convert a single-ended radio frequency (RF) receive signal to a differential RF receive signal, an amplifier chain configured to amplify the differential RF receive signal to generate a differential amplified RF receive signal, and an output balun configured to convert the differential amplified RF receive signal into a single-ended amplified RF receive signal. The LNA's amplifier chain is operable in multiple gain modes, and includes a first differential amplification stage, a second differential amplification stage, and a third differential amplification stage.

The present invention provides a common-mode rejection ratio and gain trimming circuit of differential amplifier, comprising: a first trimming unit and a second trimming unit coupled between an in-phase input voltage and a reference voltage, wherein the first trimming unit and the second trimming unit are coupled to a positive input terminal of the differential amplifier by means of tap switches; a third trimming unit and a fourth trimming unit coupled between tan inverting input voltage and an output terminal of the differential amplifier, wherein the third trimming unit and the fourth trimming unit are coupled to a negative input terminal of the differential amplifier by means of tap switches; wherein, the first trimming unit, the second trimming unit, the third trimming unit, and the fourth trimming unit comprise: a first trimming resistor string and a second trimming resistor string coupled in series; the first trimming resistor string is coupled in parallel with a first trimming auxiliary resistor string, and the second trimming resistor string is coupled in parallel with a second trimming auxiliary resistor string; wherein, the second trimming resistor string of the first trimming unit is coupled to the second trimming resistor string of the second trimming unit, and the second trimming resistor string of the third trimming unit is coupled to the second trimming resistor string of the fourth trimming unit.

The radio-frequency differential circuit includes an input balun, an output balun, a first differential amplifying circuit, a second differential amplifying circuit, a first linear feedback circuit and a second linear feedback circuit; the first differential amplifying circuit is arranged between a first output end of the input balun and a first input end of the output balun; the second differential amplifying circuit is arranged between a second output end of the input balun and a second input end of the output balun; a first end of the first linear feedback circuit is connected with the input balun, a second end of the first linear feedback circuit is connected with the first differential amplifying circuit; a first end of the second linear feedback circuit is connected with the input balun, and a second end of the second linear feedback circuit is connected with the second differential amplifying circuit.

An interface circuit includes an input circuit. The input circuit includes a first input pin, a second input pin and a third input pin. The input circuit further includes a first operational amplifier including a first output pin, a first non-inverting input pin electrically coupled to the first input pin via a first impedance and a first switch, and a first inverting input pin coupled to the first output pin. The input circuit also includes a second operational amplifier including a second output pin, a second non-inverting input electrically coupled to the second input pin via a second impedance and a second inverting input pin electrically coupled to the third input pin via a third impedance and a second switch. The first input pin and the second input pin are electrically coupled via a third switch and a fourth impedance.