| 摘要 |
The present invention relates to magnetic recording hard disk drives (HDDs) and, more particularly, to an HDD that optimizes analog write current pulses in response to frequency of transitions in data to be written to a disk. A disk drive dynamic wave shaper (DWS) write driver includes: a write current generator that produces a baseline output current for write current pulses; and an overshoot current generator that produces an overshoot current with different values. The overshoot current is added to the baseline current, as the value of the overshoot current amplitude (OSA) is selected in response to frequency of transitions in a write data signal. The write driver includes logic circuitry that detects a pattern of the transitions. Transitions that are immediately followed by a transition will receive a larger-than-nominal OSA1, transitions that are not immediately followed by a transition and that are not preceded by a long sequence of non-transitions will receive a nominal OSA2, and transitions after longer sequences of the non-transitions will receive a smaller-than-nominal OSA3. |
