A dual-mode PMOS transistor is disclosed that has a first mode of operation in which a switched n-well for the dual-mode PMOS transistor is biased to a high voltage. The dual-mode PMOS transistor has a second mode of operation in which the switched n-well is biased to a low voltage that is lower than the high voltage. The dual-mode PMOS transistor has a size and gate-oxide thickness each having a magnitude that cannot accommodate a permanent tie to the high voltage. An n-well voltage switching circuit biases the switched n-well to prevent voltage damage to the dual-mode PMOS transistor despite its relatively small size and thin gate-oxide thickness.