Patent ID: 7443199

Claim:
A circuit arrangement for voltage selection, comprising: a first input configured to receive a first supply voltage; a second input configured to receive a second supply voltage; an output configured to provide an output voltage; a first transistor connected between the first input and the output, and comprising a substrate connection coupled to a supply connection of the arrangement; a second transistor connected between the second input and the output, and comprising a substrate connection coupled to the supply connection; a third transistor connected between the first input and the supply connection; a fourth transistor connected between the second input and the supply connection; and a control circuit comprising inputs coupled to the first input and the second input, respectively, and comprising outputs coupled to a control connection of the first transistor and to a control connection of the second transistor, wherein the control circuit is configured to activate one of the first and second transistor based on a comparison of the first and second supply voltages; wherein the first and second transistors comprise normally-off field effect transistors; wherein the third transistor comprises a normally-off field effect transistor comprising a control connection coupled to the second input and a substrate connection coupled to the supply connection, and wherein the fourth transistor comprises a normally-off field effect transistor comprising a control connection coupled to the first input and a substrate connection coupled to the supply connection.