Application of reduced bias levels to disc drive read elements during periods of inactivity

A disc drive configured for communication with a host device, the disc drive comprising:

• a recording surface;
• a read/write head adjacent the recording surface and comprising separate write and read elements;
• a communication channel which processes host data transfer commands to direct the transfer of data between the recording surface and a host device;
• and
• a preamplifier driver circuit coupled to the read/write head and to the communication channel which applies an operational read bias signal of selected, nonzero magnitude to the read element to transduce data from the recording surface during an active mode of operation during which host data transfer commands are processed, and which applies a reduced read bias signal of selected, nonzero magnitude less than the magnitude of the operational read bias signal to the read element to transduce data from the recording surface during an idle mode of operation initiated after passage of a predetermined, uninterrupted period of time since the most recent host data transfer command.

A disc drive configured for communication with a host device, the disc drive comprising:

• a recording surface;
• a read/write head adjacent the recording surface and comprising separate write and read elements;
• a communication channel which processes host data transfer commands to direct the transfer of data between the recording surface and a host device;
• and
• first means for reducing electromigration in the read element.