Patent ID: 7808282

Claim:
An equalizing differential equal-voltage detector comprising: a differential input including a true differential input and a complement differential input, the true and complement differential inputs being driven to opposite states during normal operation, but the true and complement differential inputs having an equal voltage when an input-failure occurs; an equalizer, receiving the true and complement differential inputs, for attenuating frequency components to generate equalized true and complement differential inputs; a multiplier, receiving the equalized true and complement differential inputs from the equalizer, for multiplying a voltage difference between the equalized true and complement differential inputs to generate a multiplied voltage; a low-pass filter, coupled to the multiplier, for filtering the multiplied voltage to smooth variations in the multiplied voltage to generate an averaged voltage; and a comparator, coupled to receive the averaged voltage, for comparing the averaged voltage to a reference voltage, and for activating a detect signal when the averaged voltage is below the reference voltage, whereby the detect signal is activated when the voltage difference is below a threshold to signal the input-failure.