Patent ID: 7843248

Claim:
A switch circuit, comprising: a first switch having a first resistance, wherein a first voltage develops across said first switch when a first current is provided through said first switch; a reference device having a second resistance which is a known multiple of said first resistance; a current generating device which provides a reference current through said reference device for developing a second voltage across said reference device, wherein said second voltage has a level indicative of a maximum current level of said first current; a comparator which compares said first and second voltages and which provides a maximum current indication; an amplifier having an inverting input, a non-inverting input and an output; wherein said reference device has first end coupled to said inverting input and a second end coupled to said output of said amplifier; wherein said first switch has a first end coupled to said non-inverting input of said amplifier and has a second end; and wherein said comparator compares voltage levels of said output of said amplifier with said second end of said first switch.