Patent ID: 8400193

Claim:
A transistor output stage device is subject to back voltage from an output node of the device, the device comprising: a transistor having a gate, a source, a drain and a body; an electrical connection between a supply voltage node and the source; an electrical connection between the output node of the device and the drain; a comparison circuit configured and arranged to generate a selection signal in response to a comparison of a voltage on the supply voltage node and a voltage on the output node; a voltage selection circuit configured and arranged to, in response to the selection signal, provide a selected voltage that is the higher of the voltage on the supply voltage node and the voltage on the output node; an electrical connection between the body and a node providing the selected voltage; and a gate controller configured and arranged to, connect, in response to the selection signal indicating that the voltage on the supply voltage node is higher than the voltage on the output node, the gate to an input of the device, and connect, in response to the selection signal indicating that the supply voltage is lower than the voltage on the output node, the gate to the node providing the selected voltage.