Patent ID: 7403061

Claim:
An apparatus comprising: a first current source adapted to produce a first current; a second current source adapted to produce a second current; a difference detection device with a first input electrically connected to said first current source and with a second input electrically connected to said second current source; a plurality of first fuses that are electrically connected in series, wherein said plurality of first fuses are electrically connected to said first current source such that said first current flows from said first current source to said first input and also through said first fuses; and a plurality of second fuses that are electrically connected in series, wherein said plurality of second fuses are electrically connected to said second current source such that said second current flows from said second current source to said first input and also through said second fuses, wherein said first fuses and said second fuses all comprise identical fuses, and wherein said difference detection device is adapted to sense a first voltage at said first input, to sense a second voltage at said second input and to compare said first voltage to said second voltage in order to determine if said first fuses have been blown.