Data storage device detecting write pole degradation for magnetic write head

A data storage device comprising:

• a magnetic media;
• a head actuatable over the magnetic media, wherein the head comprises a write coil and a write pole;
• and
• control circuitry configured to:
• apply a current to the write coil while the head passes over a test area of the magnetic media;
• after applying the current to the write coil while the head passes over the test area, read the test area using the head to generate a first read signal;
• measure a first noise power of the first read signal;
• estimate a target current applied to the write coil that achieves a target noise power measurement based on the first noise power;
• and
• detect degradation of the write pole based on the first noise power and the target current.

A data storage device comprising:

• a magnetic media;
• a head actuatable over the magnetic media, wherein the head comprises a write coil and a write pole;
• a means for writing a test pattern to a test area of the magnetic media by applying a first current to the write coil;
• a means for applying a second current to the write coil while the head passes over the test area, wherein the second current has a polarity opposite the first current;
• a means for reading the test area from the magnetic media using the head, after writing the test pattern to the test area and after applying the second current to the write coil while the head passes over the test area, to generate a first read signal;
• a means for measuring a first noise power of the first read signal;
• and
• a means for detecting degradation of the write pole based on the first noise power.

A data storage device comprising:

• a magnetic media;
• a head actuatable over the magnetic media, wherein the head comprises a write coil and a write pole;
• and
• control circuitry configured to:
• write a test pattern to a test area of the magnetic media by applying a first current to the write coil;
• apply a second current to the write coil while the head passes over the test area, wherein the second current has a polarity opposite the first current;
• after writing the test pattern to the test area and after applying the second current to the write coil while the head passes over the test area, read the test area using the head to generate a first read signal;
• measure a first noise power of the first read signal;
• and
• detect degradation of the write pole based on the first noise power.

A data storage device comprising:

• a magnetic media;
• a head actuatable over the magnetic media, wherein the head comprises a write coil, a write pole, and a write assist element;
• and
• control circuitry configured to:
• apply a current to the write coil while the head passes over a test area of the magnetic media;
• apply a first bias to the write assist element while applying the current to the write coil while the head passes over the test area of the magnetic media;
• after applying the current to the write coil while the head passes over the test area, read the test area using the head to generate a first read signal;
• measure a first noise power of the first read signal;
• and
• detect degradation of the write pole based on the first noise power.