Amplifier circuit for buffering high slew rate signal

An amplifier circuit comprising:

• a first gain stage having a first gain stage input and a first gain stage output and configured to receive an input signal at the first gain stage input and apply a first gain to the input signal to generate a first gain stage output signal at the first gain stage output;
• a second gain stage having a second gain stage input and a second gain stage output and configured to receive the first gain stage output signal at the second gain stage input and apply a second gain to the first gain stage output signal to generate a second gain stage output signal at the second gain stage output;
• a feedforward gain stage having a feedforward gain stage input and a feedforward gain stage output and configured to receive the input signal at the feedforward gain stage input and apply a feedforward gain to the input signal to generate a feedforward gain stage output signal at the feedforward gain stage output;
• a compensation network coupled between the first gain stage output and the feedforward gain stage output;
• and
• a feedback network having a feedback gain and coupled between the second gain stage output and a feedback input of the first gain stage.

A method comprising:

• applying, with a first gain stage having a first gain stage input and a first gain stage output and configured to receive an input signal at the first gain stage input, a first gain to the input signal to generate a first gain stage output signal at the first gain stage output;
• applying, with a second gain stage having a second gain stage input and a second gain stage output and configured to receive the first gain stage output signal at the second gain stage input, a second gain to the first gain stage output signal to generate a second gain stage output signal at the second gain stage output;
• applying, with a feedforward gain stage having a feedforward gain stage input and a feedforward gain stage output and configured to receive the input signal at the feedforward gain stage input, a feedforward gain to the input signal to generate a feedforward gain stage output signal at the feedforward gain stage output, wherein the feedforward gain is inversely proportional to the second gain;
• and
• compensating for frequency in a circuit comprising the first gain stage, second gain stage, and feedforward gain stage with a compensation network coupled between the first gain stage output and the feedforward gain stage output.

A method comprising:

• applying, with a first gain stage having a first gain stage input and a first gain stage output and configured to receive an input signal at the first gain stage input, a first gain to the input signal to generate a first gain stage output signal at the first gain stage output;
• applying, with a second gain stage having a second gain stage input and a second gain stage output and configured to receive the first gain stage output signal at the second gain stage input, a second gain to the first gain stage output signal to generate a second gain stage output signal at the second gain stage output;
• applying, with a feedforward gain stage having a feedforward gain stage input and a feedforward gain stage output and configured to receive the input signal at the feedforward gain stage input, a feedforward gain to the input signal to generate a feedforward gain stage output signal at the feedforward gain stage output;
• compensating for frequency in a circuit comprising the first gain stage, second gain stage, and feedforward gain stage with a compensation network coupled between the first gain stage output and the feedforward gain stage output;
• and
• applying a feedback gain with a feedback network coupled between the second gain stage output and a feedback input of the first gain stage.

A system comprising:

• a load;
• and
• an amplifier circuit configured to drive the load, wherein the amplifier circuit comprises:
• a first gain stage having a first gain stage input and a first gain stage output and configured to receive an input signal at the first gain stage input and apply a first gain to the input signal to generate a first gain stage output signal at the first gain stage output;
• a second gain stage having a second gain stage input and a second gain stage output and configured to receive the first gain stage output signal at the second gain stage input and apply a second gain to the first gain stage output signal to generate a second gain stage output signal at the second gain stage output;
• a feedforward gain stage having a feedforward gain stage input and a feedforward gain stage output and configured to receive the input signal at the feedforward gain stage input and apply a feedforward gain to the input signal to generate a feedforward gain stage output signal at the feedforward gain stage output, wherein the feedforward gain is inversely proportional to the second gain;
• and
• a compensation network coupled between the first gain stage output and the feedforward gain stage output.

A system comprising:

• a load;
• and
• an amplifier circuit configured to drive the load, wherein the amplifier circuit comprises:
• a first gain stage having a first gain stage input and a first gain stage output and configured to receive an input signal at the first gain stage input and apply a first gain to the input signal to generate a first gain stage output signal at the first gain stage output;
• a second gain stage having a second gain stage input and a second gain stage output and configured to receive the first gain stage output signal at the second gain stage input and apply a second gain to the first gain stage output signal to generate a second gain stage output signal at the second gain stage output;
• a feedforward gain stage having a feedforward gain stage input and a feedforward gain stage output and configured to receive the input signal at the feedforward gain stage input and apply a feedforward gain to the input signal to generate a feedforward gain stage output signal at the feedforward gain stage output;
• a compensation network coupled between the first gain stage output and the feedforward gain stage output;
• and
• a feedback network having a feedback gain and coupled between the second gain stage output and a feedback input of the first gain stage.