Method and circuitry to suppress additive disturbances in data channels containing MR sensors.

摘要

A method and circuitry are disclosed for suppressing additive transient disturbances in a data channel; e.g., due to thermal transients caused by an MR transducer contacting a moving storage surface. Positive and negative envelope detectors (11, 12) each have their inputs connected to the channel, and provide respective outputs which are summed (13) and contain an envelope component and a residue component. A buffer (14) interconnects the detectors to allow both detectors (11, 12) to follow rapid positive excursions of the data channel signal. A nonlinear signal-adaptive filter (15) is connected to the summed output to further reduce the residue component. The data channel signal (or preferably the output from a delay means connected to the channel) is summed with the output from the filter. The relative amplitudes of these two outputs is set such that the resulting summed output signal is free of additive disturbances.