Rambus Inc.
Baseline wander correction

Abstract:

A receiver frontend having a high-frequency AC-coupled path in parallel to a low-frequency feed-forward path for baseline correction. The low-frequency path blocks the DC common-mode voltage of the input differential signal pair, but passes low-frequency differential signal components (e.g., long strings of a single value, or disparities in the number of 1's and 0's over a long period of time.) The low-frequency path can include a passive network for level shifting and extending the range of acceptable common-mode input voltages. The low-frequency path can also include a differential (e.g., transconductance) amplifier to isolate the common-mode input voltage from the output of the baseline wander correction circuit.