US 11,756,582 B1
System and method for disk drive fly height measurement
Paolo Pulici, Lainate (IT); Dennis Hogg, Laguna Hills, CA (US); Michele Bartolini, Carpiano (IT); Enrico Sentieri, Lodi (IT); and Enrico Mammei, Vittuone (IT)
Assigned to STMicroelectronics, Inc., Coppell, TX (US); and STMicroelectronics S.r.l., Agrate Brianza (IT)
Filed by STMicroelectronics, Inc., Coppell, TX (US); and STMicroelectronics S.r.l., Agrate Brianza (IT)
Filed on May 11, 2022, as Appl. No. 17/742,202.
Int. Cl. G11B 5/60 (2006.01); G11B 21/10 (2006.01)
CPC G11B 5/6017 (2013.01) [G11B 21/106 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system for determining a fly height, comprising:
a first head of a disk drive, the first head being adjacent to a first disk;
a second head of the disk drive, the second head being adjacent to a second disk;
a capacitive sensor circuit coupled to the first head and the second head, wherein the capacitive sensor circuit is configured to:
measure a first capacitance between the first head and the first disk, remove noise from the first capacitance using a second capacitance between the second head and the second disk, and based thereon determine a corrected first capacitance; and
a logic device coupled to the capacitive sensor circuit, the logic device being configured to determine the fly height between the first head and the first disk using the corrected first capacitance.