A data transmitter includes: a plurality of parallel driver slices, a first slice of the plurality of parallel driver slices having a first signal generator circuit with a first transistor coupled to a data signal and in series with a second transistor coupled to a first bias signal; and a first bias circuit including a third transistor and a fourth transistor in series with a first current source, the first bias circuit further including a first operational amplifier (op amp) having a first input coupled to a first reference voltage and a second input coupled between the fourth transistor and the first current source, an output of the first op amp configured to provide the first bias signal to the second transistor and to the third transistor.

Linearity is improved in an amplifier circuit without lowering gain. The amplifier circuit includes a transistor, a load, an impedance element, and a variable current source. The transistor amplifies an input signal. The load is connected between the transistor and a power supply. The impedance element is connected between the transistor and a ground terminal, and passes a direct current. The variable current source is connected to a connection part between the transistor and the impedance element, and supplies a current in accordance with a voltage of the connection part.

A data transmitter includes: a plurality of parallel driver slices, a first slice of the plurality of parallel driver slices having a first signal generator circuit with a first transistor coupled to a data signal and in series with a second transistor coupled to a first bias signal; and a first bias circuit including a third transistor and a fourth transistor in series with a first current source, the first bias circuit further including a first operational amplifier (op amp) having a first input coupled to a first reference voltage and a second input coupled between the fourth transistor and the first current source, an output of the first op amp configured to provide the first bias signal to the second transistor and to the third transistor.

Linearity is improved in an amplifier circuit without lowering gain.

The amplifier circuit includes a transistor, a load, an impedance element, and a variable current source. The transistor amplifies an input signal. The load is connected between the transistor and a power supply. The impedance element is connected between the transistor and a ground terminal, and passes a direct current. The variable current source is connected to a connection part between the transistor and the impedance element, and supplies a current in accordance with a voltage of the connection part.

An operational amplifier circuit is provided. The operational amplifier circuit includes a differential input stage circuit and a loading stage circuit. The differential input stage circuit includes an input circuit, a voltage maintaining circuit, and a current source. The input circuit includes a first input transistor and a second input transistor, for receiving a first and a second input signals, respectively. The voltage maintaining circuit includes a first branch circuit and a second branch circuit. The first branch circuit is coupled to the first input transistor for receiving the first input signal, and the second branch circuit is coupled to the second input transistor for receiving the second input signal. The current source is coupled to the first input transistor and the second input transistor. The loading stage circuit is coupled to the voltage maintaining circuit.

In accordance with an embodiment, a circuit includes an amplifier and a programmable capacitor coupled between an output of the first non-inverting and the input of the first amplifier.

An operational amplifier circuit is provided. The operational amplifier circuit includes a differential input stage circuit and a loading stage circuit. The differential input stage circuit includes an input circuit, a voltage maintaining circuit, and a current source. The input circuit includes a first input transistor and a second input transistor, for receiving a first and a second input signals, respectively. The voltage maintaining circuit includes a first branch circuit and a second branch circuit. The first branch circuit is coupled to the first input transistor for receiving the first input signal, and the second branch circuit is coupled to the second input transistor for receiving the second input signal. The current source is coupled to the first input transistor and the second input transistor. The loading stage circuit is coupled to the voltage maintaining circuit.

An operational amplifier circuit is provided. The operational amplifier circuit includes a differential input stage circuit and a loading stage circuit. The differential input stage circuit includes an input circuit, a voltage maintaining circuit, and a current source. The input circuit includes a first input transistor and a second input transistor, for receiving a first and a second input signals, respectively. The voltage maintaining circuit includes a first branch circuit and a second branch circuit. The first branch circuit is coupled to the first input transistor for receiving the first input signal, and the second branch circuit is coupled to the second input transistor for receiving the second input signal. The current source is coupled to the first input transistor and the second input transistor. The loading stage circuit is coupled to the voltage maintaining circuit.

An operational amplifier circuit is provided. The operational amplifier circuit includes a differential input stage circuit and a loading stage circuit. The differential input stage circuit includes an input circuit, a voltage maintaining circuit, and a current source. The input circuit includes a first input transistor and a second input transistor, for receiving a first and a second input signals, respectively. The voltage maintaining circuit includes a first branch circuit and a second branch circuit. The first branch circuit is coupled to the first input transistor for receiving the first input signal, and the second branch circuit is coupled to the second input transistor for receiving the second input signal. The current source is coupled to the first input transistor and the second input transistor. The loading stage circuit is coupled to the voltage maintaining circuit.

In accordance with an embodiment, a circuit includes an amplifier and a programmable capacitor coupled between an output of the first non-inverting and the input of the first amplifier.