Using Multiple-Driver Stages to Realize Fast Rise/Fall Time And Large Current Capability

An amplifier circuit comprising:

• a driver circuit comprising:
• a first sub-driver circuit having an input coupled to receive a first pulsed signal, the first sub-driver circuit being configured to generate a first driver signal at an output thereof in response to the first pulsed signal, the first driver signal having relatively fast edge transitions and a low current capability;
• and
• a second sub-driver circuit having an input coupled to receive a second pulsed signal, the second sub-driver circuit being configured to generate a second driver signal at an output thereof in response to the second pulsed signal, the second driver signal having edge transitions that are slower than those of the first driver signal and a current capability that is higher than that of the first driver signal;
• and
• a combiner to combine the first driver signal and the second driver signal to generate a combined driver signal having fast edge transitions associated with the first driver signal and higher current capability associated with the second driver signal;
• and
• a power amplifier (PA) circuit coupled to receive the combined driver signal at an input thereof, the PA being configured to amplify the combined driver signal to generate an amplified output signal at en output thereof, wherein the edge transitions and current capability of the combined driver signal are sufficient to provide desired operating characteristics for the amplifier circuit.

A method of driving an amplifier circuit, comprising:

• generating a first driver signal and a second driver signal, the first driver signal having faster edge transitions than the second driver signal and the second driver signal having greater current capability than the first driver signal;
• combining the first and second driver signals to generate a combined driver signal having a high power capability and a fast rise/fall time capability;
• and
• providing the combined driver signal to an input of the amplifier circuit for generating an amplified output signal from the combined driver signal.