US 11,657,846 B1
Automatic skew calibration circuit for pattern-dependent dynamic wave shaping for HDD preamplifier write
Enrico Mammei, Vittuone (IT); Paolo Sanna, Rho (IT); Dennis Hogg, Laguna Hills, CA (US); and Edoardo Contini, Milan (IT)
Assigned to STMicroelectronics S.r.l., Agrate Brianza (IT); and STMicroelectronics, Inc., Coppell, TX (US)
Filed by STMicroelectronics S.r.l., Agrate Brianza (IT); and STMicroelectronics, Inc., Coppell, TX (US)
Filed on Mar. 31, 2022, as Appl. No. 17/710,608.
Int. Cl. G11B 20/10 (2006.01)
CPC G11B 20/10027 (2013.01) 20 Claims
OG exemplary drawing
 
1. A method to determine a relative delay between a current-overshoot signal and a write data signal for a hard disk drive preamplifier, the method comprising:
using a memory element to strobe a test current-overshoot signal with a test data signal;
counting a number of strobed transitions of the test current-overshoot signal;
adjusting the relative delay based on the number of strobed transitions;
setting a phase difference between the current-overshoot signal and the write data signal according to the relative delay; and
using the memory element to strobe the current-overshoot signal with the write data signal.