A driver circuit is provided for enabling a transistor collector-emitter path to be used as a broadband periodic switch. The broadband driver circuit controls the magnitude of the transistor base-emitter current in order to enable a CLOSED switch state and to simultaneously control the magnitude of the transistor base-emitter reverse-bias voltage in order to enable the OPEN-switch state. The precise control of these parameters minimizes base-charge storage and prevents reverse-breakdown failure.