Patent ID: 7116151

Claim:
A circuit for voltage switching in an integrated circuit, comprising: a first p-type transistor having a source, a gate, a drain, and a substrate, the substrate coupled with the source, the source coupled with a high voltage potential line to receive a voltage potential that is higher than a gate-to-drain pn-junction breakdown voltage associated with the first transistor, and the gate coupled with a line to have a voltage potential substantially equal to the high voltage; a second p-type transistor having a source, a gate, a drain, and a substrate, the substrate coupled with the source, the source coupled with a low voltage potential line, the low voltage controlled to be lower than the high voltage, the gate coupled with a control signal line, and the drain to have a voltage potential substantially equal to the low voltage, the difference between the high voltage and the voltage on the drain equal to or higher than the breakdown voltage; and a third p-type transistor having a source, a gate, a drain, and a substrate, the substrate coupled with the source of the first transistor, the source coupled with the drain of the first transistor, the drain coupled with the drain of the second transistor, and the gate coupled with a bias signal line to have a voltage potential between the high voltage and the voltage on the drain of the second transistor.