A differential amplifier is provided, in which generation of unnecessary harmonic distortion in the differential output signal is suppressed. A common mode feedback circuit increases or decreases operating points of an inverting output terminal and a non-inverting output terminal such that an intermediate voltage of voltages respectively provided to an inverting input terminal and a non-inverting input terminal is consistent with to a reference voltage. Variations in voltage at the inverting input terminal and the non-inverting input terminal are suppressed, variations in electrical properties of elements connected to the input terminals are suppressed. Therefore, it is possible to suppress generation of harmonic distortion in the output signals from the inverting output terminal and the non-inverting output terminal.

The disclosure relates to an alternating current (AC) coupling circuit including first and second capacitors having first and second input terminals configured to receive an input differential signal and generate an output differential signal at first and second output terminals of the first and second capacitors. The AC coupling circuit further includes a baseline wander correction circuit configured to make the output differential signal resistant to baseline wander due to the input differential signal including one or more time intervals of unbalanced data. The baseline wander correction circuit includes a differential difference amplifier (DDA) having a first differential input configured to receive the input differential signal, a differential output configured to generate a compensation differential signal, and a second differential input configured to receive the compensation differential signal. The compensation differential signal is applied to the output terminals of the first and second capacitors via a pair of resistors, respectively.

Methods and apparatus for a signal isolator that mitigates the effects of CMTI strikes. In embodiments, a first die comprises a transmit module and the first die has a first voltage domain; and a second die comprises a receive module including a receive amplifier configured to receive from the transmit module a transmit signal that includes a differential signal and a common mode current. The second die may have a second voltage domain with the first and second die being separated by an isolation barrier. In embodiment, the receive amplifier includes a differential amplifier to receive the differential input signal from the transmit module; and a common mode module configured to sense the common mode current and sink or source the common mode current and minimize changes to an input impedance of the receive amplifier.

A differential amplifier is provided, in which generation of unnecessary harmonic distortion in the differential output signal is suppressed. A common mode feedback circuit increases or decreases operating points of an inverting output terminal and a non-inverting output terminal such that an intermediate voltage of voltages respectively provided to an inverting input terminal and a non-inverting input terminal is consistent with to a reference voltage. Variations in voltage at the inverting input terminal and the non-inverting input terminal are suppressed, variations in electrical properties of elements connected to the input terminals are suppressed. Therefore, it is possible to suppress generation of harmonic distortion in the output signals from the inverting output terminal and the non-inverting output terminal.

Implementations provide a receiver circuit that includes: an alternate current (AC)-coupling network to filter an input signal, the AC-coupling network including a first RC filter connected between a first input node and a first common node and a second RC filter connected between a second input node and the first common node; a differential amplifier coupled to the AC-coupling network and configured to receive a filtered input signal from the AC-coupling network and generate an output signal, the differential amplifier including a differential pair of transistors and a common-mode measurement network coupled to source terminals of a first and a second transistors in the differential pair; and a first operational amplifier having an input coupled to output terminal of the common-mode measurement network and an output coupled to the first common node.

Implementations provide a receiver circuit that includes: an alternate current (AC)-coupling network to filter an input signal, the AC-coupling network including a first RC filter connected between a first input node and a first common node and a second RC filter connected between a second input node and the first common node; a differential amplifier coupled to the AC-coupling network and configured to receive a filtered input signal from the AC-coupling network and generate an output signal, the differential amplifier including a differential pair of transistors and a common-mode measurement network coupled to source terminals of a first and a second transistors in the differential pair; and a first operational amplifier having an input coupled to output terminal of the common-mode measurement network and an output coupled to the first common node.

An amplifier circuit. In some embodiments, the amplifier circuit includes: a telescopic amplifier, and a common mode feedback amplifier. The telescopic amplifier has a first signal input, a second signal input, a first output, a second output, a common mode feedback input, a first pole-splitting capacitor, and a second pole-splitting capacitor. The common mode feedback amplifier has an output connected to the common mode feedback input of the telescopic amplifier. The first pole-splitting capacitor is connected between the common mode feedback input of the telescopic amplifier and the first output of the telescopic amplifier, and the second pole-splitting capacitor is connected between the common mode feedback input of the telescopic amplifier and the second output of the telescopic amplifier.

An amplifier circuit. In some embodiments, the amplifier circuit includes: a telescopic amplifier, and a common mode feedback amplifier. The telescopic amplifier has a first signal input, a second signal input, a first output, a second output, a common mode feedback input, a first pole-splitting capacitor, and a second pole-splitting capacitor. The common mode feedback amplifier has an output connected to the common mode feedback input of the telescopic amplifier. The first pole-splitting capacitor is connected between the common mode feedback input of the telescopic amplifier and the first output of the telescopic amplifier, and the second pole-splitting capacitor is connected between the common mode feedback input of the telescopic amplifier and the second output of the telescopic amplifier.