Patent ID: 7224195
Filing Date: 2007-05-29
Classification: H03K

Abstract:
1. An output driver circuit, comprising: a first transistor coupled between a power supply voltage and an output pad; a second transistor coupled between the first transistor and the output pad; a level shifter coupled between the first transistor and an input signal, the level shifter providing a signal to a gate of the first transistor; a control circuit coupled to a gate of the second transistor, the control circuit providing a signal to the gate of the second transistor in response to the input signal and a supply voltage control signal; wherein the level shifter and the control circuit are coupled to a bias voltage, the bias voltage being set to ground when the supply voltage control signal indicates a low supply voltage and the bias voltage being set to an intermediate voltage when the supply voltage control signal indicates a high supply voltage, and wherein voltages applied across a gate oxide of the first transistor and a gate oxide of the second transistor do not exceed the low supply voltage.