A buffer circuit has a first transistor and a second transistor in a cascode, and a buffer switch coupled from an output of the buffer to a gate of the second transistor. The buffer circuit is bootstrapped by a bootstrap capacitor, a diode circuit, and a bootstrap switch. The bootstrap capacitor is coupled from the output to the gate of the second transistor through the bootstrap switch. A potential difference is set up across the bootstrap capacitor through the diode circuit. When a low input is given to the buffer circuit, the second transistor turns off and the output goes to a high bias voltage through the first transistor. When a high input is given, the first transistor turns off, the second transistor turns on, and as the output goes low, the gate of the second transistor is bootstrapped to drop the output completely down to a low bias voltage.