Patent ID: 6188540
Filing Date: 2001-02-13
Classification: G11B

Abstract:
A system for moving a plurality of heads in a disk drive, the system comprising:a plurality of disks for storing data;a plurality of heads for reading data from or writing data to the disks;a voice coil motor for moving the plurality of heads, the voice coil motor having a voice coil with a first end and a second end;a voice coil motor driver for providing a voltage across the voice coil during read/write operations, wherein the voice coil motor driver is coupled to both the first end and the second end of the voice coil;a voltage clamp device for providing a generally constant voltage across the voice coil during head parking, wherein the voltage clamp device is coupled to the first end of the voice coil;a park voltage source for energizing the voltage clamp device; anda park voltage resistive network for coupling the park voltage source to the voltage clamp device, wherein a first end of the park voltage resistive network is coupled to the park voltage source, and a second end of the park voltage resistive network is coupled to the voltage clamp device;wherein the voltage clamp device comprises:a device input terminal for receiving a time varying voltage;a device output terminal for providing a generally constant voltage signal;a voltage divider having an input terminal coupled to the device input terminal and an output terminal for providing a time varying control voltage;a first transistor having a clamp terminal coupled to the device output terminal, a control terminal coupled to the voltage divider output terminal, and a reference terminal coupled to a voltage reference; anda switch coupled between the device input terminal and the device output terminal for enabling the first transistor.