METHODS AND APPARATUSES FOR SELECTABLE VOLTAGE SUPPLY

摘要

A circuit which selects a supply voltage from a plurality of voltage supplies is presented. The circuit includes a first transistor (215) configured to select a first voltage supply (240), a second transistor (210) configured to select a second voltage sup?ly (230), a first parasitic current inhibitor (205) coupled the first transistor, (215) the first voltage supply, (240) and the second voltage supply, (230) where the first parasitic current inhibitor (205) automatically utilizes the voltage supply providing the highest voltage for preventing a substrate current from flowing through a bulk node of the first transistor (215), and a second parasitic current inhibitor (207) coupled the second transistor (210), the first voltage supply (240), and the second voltage supply(230), where the second parasitic current inhibitor (207) automatically utilizes the voltage supply providing the highest voltage for preventing a substrate current from flowing through a bulk node of the second transistor (210).