Patent ID: 7786697

Claim:
A battery charger comprising: a power input for receiving a power supply for charging a battery; an integrated circuit chip, operable at an operating voltage, supplying on-chip functions for battery charger operation, the chip being coupled to said power input and adapted to communicate with said battery; said integrated circuit chip comprising: a voltage input, V chg , a charge controller and/or a charger circuit, said voltage input, V chg being coupled to the charge controller and/or charger circuit; and a voltage regulator is disposed within said integrated circuit chip and interposed between said voltage input, V chg , and said charge controller and/or charger circuit, said voltage regulator adapted for regulating the voltage at said voltage input, V chg , so as to regulate the voltage input, V chg , to provide a regulated voltage, V reg , the regulated voltage V reg being compatible with said operating voltage of said integrated circuit chip, said voltage regulator comprises a MOS device configured in diode connected mode to act as a diode to provide a substantially constant voltage drop between said voltage input, V chg , and said regulated voltage, V reg ; and the MOS device comprises a first node, a second node, and a control node; and one of the first and second nodes is directly connected to the control node such that the MOS device acts as the diode.