Patent ID: 8022574

Claim:
A maximum voltage source selector for a semiconductor device operative in a disable state or an enable state, the maximum voltage source selector comprising: an output unit comprising; an output node providing a maximum voltage selected from a first input voltage and a second input voltage, first and second gate transistors commonly coupled to the output node and respectively configured to select and provide the greater of the first and second input voltages to the output node in response to first and second selection signals, and without regard to whether the semiconductor device is in the disable state or the enable state, a first input node receiving the first input voltage and a second input node receiving the second input voltage, wherein the first gate transistor is connected between the first input node and the output node and the second gate transistor is connected between the second input node and the output node, a first resistance transistor providing a voltage proportional to the first input voltage to a gate of the second gate transistor, and a second resistance transistor providing a voltage proportional to the second input voltage to a gate of the first gate transistor; and a selection unit generating the first and second selection signals in response to the first and second input voltages.