US 11,798,587 B1
Reducing noise in back EMF sensing for data storage
Guoxiao Guo, Irvine, CA (US); Jianbin Nie, Fremont, CA (US); Triet Tieu, Milipitas, CA (US); Duc H. Banh, San Jose, CA (US); and Tianyu Jiang, San Jose, CA (US)
Assigned to Western Digital Technologies, Inc., San Jose, CA (US)
Filed by Western Digital Technologies, Inc., San Jose, CA (US)
Filed on Mar. 14, 2022, as Appl. No. 17/693,626.
Int. Cl. G11B 5/55 (2006.01)
CPC G11B 5/5543 (2013.01) [G11B 5/5565 (2013.01); G11B 5/5573 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A data storage device comprising:
a voice coil motor (VCM); and
one or more processing devices, configured to:
actuate the VCM;
switch on measuring a back electromotive force (BEMF) from the VCM for intervals of an initial BEMF measurement that are free of spikes in the initial BEMF measurement, free of spikes being indicative of amplitude measurements not exceeding 5% of a peak amplitude of a preceding interval where a spike has occurred; and
process a measured BEMF signal from the intervals of the initial BEMF measurement that are free of spikes in a change of current term of the initial BEMF measurement.