Disk drive establishing write current limits prior to optimizing the write current for a plurality of tracks

Abstract

A disk drive is disclosed comprising control circuitry operable to calibrate a write current parameter. A write current is initialized to an initial write current INIT_Iw, and an overshoot is initialized to a maximum MAX_OS. The write current is swept from INIT_Iw to a maximum write current MAX_Iw while writing and reading data from a target track to measure a first quality metric. A second quality metric associated with wide track erasure is also measured. A quality of the write operations is determined in response to the first and second quality metrics. When the quality of the write operations does not exceed a threshold, at least one of the MAX_Iw and MAX_OS is decreased and the process is repeated. Otherwise, the write current is swept from a minimum write current limit MAX_Iw to the adjusted MAX_Iw for a plurality of tracks to find an optimal write current for each track.