Patent ID: 7417913

Claim:
An apparatus, comprising: a first fuse device configured to receive a supply voltage from a supply voltage source, and output a first voltages; a first resistance device coupled to the first fuse device and configured to switch between on and off to selectively adjust ust the first voltage; a second fuse device parallel to the first fuse device relative to the supply voltage source and configured to receive the supply voltage from the supply voltage source, and output a second voltage; and a second resistance device coupled to the second fuse device and configured to switch between on and off to selectively adjust the second voltage, the first and second resistance devices configured to asymmetrically adjust the first and second voltages; and a sense amplifier serielly connected to the first and second resistance devices such that the first resisitance device is connected in series between the first fuse device and the sense amplifier, and the second resistance device is connected in series between the second fuse device and the sense amplifier, wherein the sense amplifier is configured to sense a difference between the adjusted first voltage and the adjusted second voltage.