US 12,334,119 B2
Method of operating hard disk drives, corresponding control circuit, hard disk drive and processing device
Michele Boscolo Berto, Milan (IT)
Assigned to STMicroelectronics International N.V., Geneva (CH)
Filed by STMicroelectronics International N.V., Geneva (CH)
Filed on May 30, 2024, as Appl. No. 18/678,645.
Claims priority of application No. 102023000012570 (IT), filed on Jun. 19, 2023.
Prior Publication US 2024/0420737 A1, Dec. 19, 2024
Int. Cl. G11B 27/36 (2006.01); H02P 7/025 (2016.01)
CPC G11B 27/36 (2013.01) [H02P 7/025 (2016.02)] 20 Claims
OG exemplary drawing
 
1. A method to operate a voice coil motor (VCM) in a hard disk drive (HDD), the method comprising:
sampling a first value of a voltage across the VCM at a first time corresponding to an end of an OFF time of the HDD alternating between ON and OFF times;
sampling a second value of the voltage across the VCM at a second time corresponding to a drive current of the VCM zeroing following supply of drive current to the VCM being countered during the OFF time, the drive current supplied to the VCM being facilitated and countered, respectively, with a variable voltage across the VCM during the ON and OFF times, an intensity of the drive current controlled as a function of a Back ElectroMotive Force (BEMF) of the VCM; and
calculating the BEMF of the VCM as a function of the first value and the second value.