Electromagnetic interference cancellation for wireline receivers

A receiver chip for wireline communication using baseband transmission, the receiver chip comprising:

• a baseband receiver configured to receive an input signal transmitted over a wireline link, wherein the input signal is encoded with digital data and the baseband receiver recovers the digital data from the received input signal;
• and
• electromagnetic interference (EMI) cancellation circuitry coupled to the baseband receiver, wherein:
• the EMI cancellation circuitry produces an EMI cancellation signal from the received input signal, wherein the EMI cancellation signal is based upon EMI in the received input signal;
• and
• the baseband receiver receives the EMI cancellation signal from the EMI cancellation circuitry and, based on the EMI cancellation signal, reduces an effect of the EMI on recovering the digital data,
• wherein the input signal comprises a differential input signal;
• wherein the EMI cancellation circuitry comprises:
• an analog common mode sense circuit that extracts a common mode signal from the differential input signal;
• a digital adaptive filter that produces the EMI cancellation signal from the common mode signal;
• an analog-to-digital converter (ADC) coupled between the analog common mode sense circuit and the digital adaptive filter;
• and
• a feedback loop from the baseband receiver to the digital adaptive filter;
• and
• wherein the baseband receiver comprises an ADC that samples at a frequency based on a data transmission baud rate of the digital data, and the ADC in the EMI cancellation circuitry oversamples relative to the frequency of the ADC in the baseband receiver but has a lower resolution than the ADC in the baseband receiver.