US 12,170,103 B2
System and method for disk drive fly height measurement
Paolo Pulici, Lainate Mi (IT); Michele Bartolini, Carpiano (IT); Enrico Sentieri, Lodi (IT); Enrico Mammei, Vittuone (IT); Matteo Tonelli, Parma (IT); and Dennis Hogg, Meridian, ID (US)
Filed by STMicroelectronics International N.V., Geneva (CH)
Filed on Aug. 11, 2023, as Appl. No. 18/448,737.
Application 18/448,737 is a continuation in part of application No. 17/742,202, filed on May 11, 2022, granted, now 11,756,582.
Prior Publication US 2024/0005956 A1, Jan. 4, 2024
Int. Cl. G11B 5/60 (2006.01); G11B 21/10 (2006.01)
CPC G11B 5/607 (2013.01) [G11B 5/6017 (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 capacitive fly height sensor circuit coupled to the first head, wherein the capacitive fly height sensor circuit is configured to measure a first capacitance between the first head and the first disk;
a reference sensor circuit, wherein the reference sensor circuit is configured to experience a same thermal drift as the capacitive fly height sensor circuit; and
a logic circuit, the logic circuit being coupled to the capacitive fly height sensor circuit and the reference sensor circuit, wherein the logic circuit is configured to:
remove noise to correct a measurement of the capacitive fly height sensor circuit using a measurement of the reference sensor circuit; and
determine the fly height between the first head and the first disk using the corrected measurement of the capacitive fly height sensor circuit.