Patent ID: 8731031

Claim:
An integrated circuit device comprising: an equalizer configured to output a first input voltage and a second input voltage, the first input voltage carrying serial data at a frequency of at least 1 GHz, the second input voltage carrying serial data at a frequency of at least 1 GHz; a digital to analog converter configured to output a first DAC signal and a second DAC signal, the first DAC signal and the second DAC signals being characterized by a frequency of less than 0.5 GHz; a loopback driver being configured to output a first loopback signal and a second loopback signal, the first loopback signal and the second loopback signal being characterized by a frequency of at least 1 GHz; a first switch coupled to the first loopback signal, the first switch comprising a first filter; a second switch coupled to the second loopback signal, the second switch comprising a second filter; and a sense amplifier having first input coupled to the first input voltage, a second input coupled to the second input voltage, a third input coupled to the first loopback signal through the first switch and the first DAC signal, a fourth input coupled to the second loopback signal through the second switch and the second DAC signal.