An integrated circuit comprises a first amplifier circuit with a push-pull amplifier configured to be calibrated to a low second order distortion. The integrated circuit further comprises a second amplifier circuit with at least one push-pull amplifier, wherein a size ratio between sizes of the transistors is adjustable by adjusting the size of at least one transistor device. The size ratio can be consecutively adjusted to a plurality of values, and for each value, a first output signal of a push-pull amplifier with an applied test signal and a second output signal of a push-pull amplifier without applied test signal, are determined. The size ratio for which a difference between the push-pull amplifier output signals is closest to zero is determined, and the push-pull amplifier of the first amplifier circuit is calibrated in dependence of the determined size ratio.

Described examples include Ethernet physical layer (PHY) interface integrated circuits with transmit interface circuitry for transmitting data to an Ethernet network through a magnetic interface, which includes a voltage mode first amplifier with an output that generates a first voltage signal from a supply voltage according to a data input signal. The transmit interface circuit also includes a feedforward second amplifier circuit with an output stage that operates in a first mode to generate a current signal from the supply voltage according to the first voltage signal and to provide the current signal to the first amplifier output to boost a peak voltage at the output above the supply voltage to facilitate support for higher peak signal voltage swings for 10Base-T applications while using 2.5 volt or other low voltage supply levels.

In an embodiment, a class-AB amplifier includes: an output stage that includes a pair of half-bridges configured to be coupled to a load; and a current sensing circuit coupled to a first half-bridge of the pair of half-bridges. The current sensing circuit includes a resistive element and is configured to sense a load current flowing through the load by: mirroring a current flowing through a first transistor of the first half-bridge to generate a mirrored current, flowing the mirrored current through the resistive element, and sensing the load current based on a voltage of the resistive element.

In an embodiment, a class-AB amplifier includes: an output stage that includes a pair of half-bridges configured to be coupled to a load; and a current sensing circuit coupled to a first half-bridge of the pair of half-bridges. The current sensing circuit includes a resistive element and is configured to sense a load current flowing through the load by: mirroring a current flowing through a first transistor of the first half-bridge to generate a mirrored current, flowing the mirrored current through the resistive element, and sensing the load current based on a voltage of the resistive element.

Described examples include Ethernet physical layer (PHY) interface integrated circuits with transmit interface circuitry for transmitting data to an Ethernet network through a magnetic interface, which includes a voltage mode first amplifier with an output that generates a first voltage signal from a supply voltage according to a data input signal. The transmit interface circuit also includes a feedforward second amplifier circuit with an output stage that operates in a first mode to generate a current signal from the supply voltage according to the first voltage signal and to provide the current signal to the first amplifier output to boost a peak voltage at the output above the supply voltage to facilitate support for higher peak signal voltage swings for 10Base-T applications while using 2.5 volt or other low voltage supply levels.

Described examples include Ethernet physical layer (PHY) interface integrated circuits with transmit interface circuitry for transmitting data to an Ethernet network through a magnetic interface, which includes a voltage mode first amplifier with an output that generates a first voltage signal from a supply voltage according to a data input signal. The transmit interface circuit also includes a feedforward second amplifier circuit with an output stage that operates in a first mode to generate a current signal from the supply voltage according to the first voltage signal and to provide the current signal to the first amplifier output to boost a peak voltage at the output above the supply voltage to facilitate support for higher peak signal voltage swings for 10Base-T applications while using 2.5 volt or other low voltage supply levels.

An integrated circuit comprises a first amplifier circuit with a push-pull amplifier configured to be calibrated to a low second order distortion. The integrated circuit further comprises a second amplifier circuit with at least one push-pull amplifier, wherein a size ratio between sizes of the transistors is adjustable by adjusting the size of at least one transistor device. The size ratio can be consecutively adjusted to a plurality of values, and for each value, a first output signal of a push-pull amplifier with an applied test signal and a second output signal of a push-pull amplifier without applied test signal, are determined. The size ratio for which a difference between the push-pull amplifier output signals is closest to zero is determined, and the push-pull amplifier of the first amplifier circuit is calibrated in dependence of the determined size ratio.