Head amplifier circuit with function for degaussing residual magnetism of recording head

A hard disk drive with a recording head used to magnetically record data on a magnetic disk medium, comprising:

• a disk controller configured to designate a data-recording mode for recording write data on the magnetic disk medium;
• and
• a head amplifier circuit including a driver circuit and a control circuit,
• the driver circuit being configured to supply, in a data-recording mode, the recording head with a recording current corresponding to write data and serving as a first recording current, and to supply, in a degaussing mode, the recording head with a degaussing current serving as a second recording current, the second recording current having a rising period and a falling period set longer than a rising period and a falling period of the first recording current,
• the control circuit being configured to control switching from the data-recording mode to the degaussing mode to control the driver circuit.

A method of eliminating a residual magnetism of a recording head, the recording head being used to magnetically record data on a magnetic disk medium in a hard disk drive, comprising:

• supplying, in a data-recording mode, the recording head with a recording current corresponding to write data and serving as a first recording current;
• switching the hard disk drive from the data-recording mode to a degaussing mode for eliminating the residual magnetism of the recording head;
• and
• supplying, in the degaussing mode, the recording head with a degaussing current serving as a second recording current, the second recording current having a rising period and a falling period set longer than a rising period and a falling period of the first recording current.