Patent ID: 8773086

Claim:
A voltage adjustment circuit for reducing a leakage current between a drain terminal and a source terminal of a metal oxide semiconductor (MOS) transistor in an electric system during a power save mode, the voltage adjustment circuit comprising: an input terminal and an output terminal, wherein the input terminal is configured to receive an input reference voltage to be potentially supplied to the electric system during the power save mode; a detector coupled to the input terminal, wherein the detector is configured to (i) monitor the input reference voltage at the input terminal, and (ii) generate a voltage drop to reduce the input reference voltage in response to the input reference voltage exceeding a first threshold; a voltage drop circuit configured to (i) in response to the input reference voltage exceeding the first threshold, reduce the input reference voltage based on the voltage drop and pass the reduced input reference voltage to the output terminal, wherein the reduced input reference voltage is supplied from the output terminal to the electronic system, and (ii) in response to the input reference voltage not exceeding the first threshold, pass the input reference voltage, unchanged, to the output terminal, wherein the unchanged input reference voltage is supplied from the output terminal to the electronic system; a switch having a first terminal coupled to receive the input reference voltage; a comparator having a first terminal coupled to the input reference voltage, a second terminal coupled to a threshold voltage that is representative of the first threshold, and an output coupled to the switch; and a DC to DC converter coupled to the output terminal of the voltage adjustment circuit and coupled to an output terminal of the switch, wherein the comparator generates a first signal when the input reference voltage exceeds the threshold voltage, and in accordance therewith, the switch is opened and the voltage drop circuit reduces the input reference voltage, and wherein the comparator generates a second signal when the input reference voltage does not exceed the threshold voltage, and in accordance therewith, the switch is closed and the input reference voltage is coupled to an input of the DC to DC converter.