| 摘要 |
A current driver for supplying write current to an inductive write head of a disk drive includes an H-switch and first and second damping circuits connected across the inductive head. Each damping circuit includes a first controlled resistor (such as a MOS transistor) connected across the head. A delay circuit is connected between a load terminal at one side of the head and the control terminal of the MOS transistor, and is responsive to a transient voltage at the load terminal to delay the transient voltage to the control terminal of the MOS transistor for a predetermined delay period. The MOS transistor is responsive to the delayed transient voltage to provide a predetermined electrical resistance across the head to dampen undershoot and ringing in the driver. The MOS transistor turns off when the voltage at the load terminals stabilizes, thereby removing the damping resistance from the circuit.
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