Patent ID: 8130011

Claim:
An apparatus comprising: a first transistor having a control electrode connected to a first voltage source carrying a control signal, the first transistor being connected between a switch and a ground; a sense resistor having a first end and a second end, with the first end connected to the ground; a second transistor having a control electrode connected to the first voltage source carrying the control signal, the second transistor being connected between the switch and the second end of the sense resistor; and a comparator electrically connected to the second end of the sense resistor, thereby receiving a sense voltage at a first input, and receiving at a second input a reference voltage supplied from voltage dividing resistors connected between a second voltage source and the ground, for comparing the sense voltage with the reference voltage and outputting a difference between the sense voltage and the reference voltage to a logic circuit, wherein the voltage dividing resistors include: a first voltage dividing resistor connected between the second voltage source and the second input terminal of the comparator; and a second voltage dividing resistor connected between the second input terminal of the comparator and the ground, wherein the connections to ground include a parasitic resistance.