Patent ID: 7733131

Claim:
A signal presence detection device comprising: a first reference voltage generation device; a second reference voltage generation device; a third reference voltage generation device; a signal conditioning device having a first output, said first output being mutually coupled to said first and second reference voltage generation devices; a comparison device, said comparison device being operatively coupled to said first reference voltage generation device, said second reference voltage generation device and said third reference voltage generation device, said comparison device being adapted to compare a voltage of said first reference voltage generation device to a voltage of said third reference voltage device and said comparison device being adapted to compare a voltage of said second reference voltage generation device to said voltage of said third reference voltage device to produce respective first and second comparison state signals; and an XOR logic gate device, said XOR logic gate device being adapted to receive said first and second comparison state signals at respective first and second inputs thereof and produce a signal presence detection output.