US 11,990,161 B2
Data storage device pre-biasing write current for energy assisted magnetic recording
Joey M. Poss, Rochester, MN (US); Naoto Ito, Kanagawa (JP); and Phillip S. Haralson, Huntington Beach, CA (US)
Assigned to Western Digital Technologies, Inc., San Jose, CA (US)
Filed by Western Digital Technologies, Inc., San Jose, CA (US)
Filed on May 23, 2023, as Appl. No. 18/322,163.
Application 18/322,163 is a division of application No. 17/241,990, filed on Apr. 27, 2021, granted, now 11,694,712.
Prior Publication US 2023/0298621 A1, Sep. 21, 2023
Int. Cl. G11B 5/02 (2006.01); G11B 5/012 (2006.01); G11B 20/10 (2006.01); G11B 5/00 (2006.01); G11B 5/027 (2006.01); G11B 5/54 (2006.01)
CPC G11B 5/02 (2013.01) [G11B 5/012 (2013.01); G11B 20/10027 (2013.01); G11B 2005/001 (2013.01); G11B 2005/0021 (2013.01); G11B 2005/0024 (2013.01); G11B 5/027 (2013.01); G11B 5/54 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A preamp circuit comprising:
a write amplifier configured to generate a write current for a write coil of a head;
an interface configured to receive a write signal;
an oscillator configured to generate an oscillating signal; and
write control logic configured to:
during a pre-bias interval, configure the write amplifier with a first gain and apply the oscillating signal to the write amplifier; and
during a write interval, configure the write amplifier with a second gain lower than the first gain and apply the write signal to the write amplifier.