USING PMOS POWER SWITCH IN A COMBINATION SWITCHING AND LINEAR REGULATOR

摘要

A P-MOS transistor may be used as either a switch in a DC-DC converter or as a pass transistor of a linear regulator. When a supply voltage is above a certain voltage, the P-MOS transistor will be used in the DC-DC converter and when below the certain voltage the P-MOS transistor will be used in the linear regulator. The supply voltage may be monitored with a voltage comparator that compares the supply voltage to the certain voltage. Above the certain voltage the DC-DC converter is more efficient than the linear regulator and below the certain voltage the linear voltage regulator is more efficient than the DC-DC converter. Alternatively, selecting either the DC-DC converter or linear regulator may be done by using bonding, a jumper, a fuse link or programming a bit for different product applications during integrated circuit package fabrication or end product manufacturing.