Patent ID: 8258853

Claim:
A power switch circuit comprising: a voltage selecting circuit comprising: a first PMOS having a source end coupled to a first voltage source, a gate end coupled to a second voltage source, a drain end and a body end coupled to the drain end; and a second PMOS having a source end coupled to the second voltage source, a gate end coupled to the first voltage source, a drain end coupled to the drain end of the first PMOS, and a body end coupled to the drain end of the second PMOS; a control circuit having an input end coupled to the second voltage source; and a pass stage coupled to the voltage selecting circuit, the pass stage comprising an auxiliary PMOS having a source end coupled to the second voltage source, a gate end coupled to an output end of the control circuit, a drain end coupled to the drain end of the first PMOS, and a body end coupled to the drain end of the auxiliary PMOS.