The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 22, 2003
Filed:
May. 17, 2001
Jason P. Brenden, Eagan, MN (US);
David W. Kelly, Lino Lakes, MN (US);
Michael J. Peterson, Eagan, MN (US);
Agere Systems Inc., Allentown, PA (US);
Abstract
A pulse width modulation controller for a hard disc drive spindle motor controls the rapid spin up of the spindle motor from a stop condition to normal operating speed using a multi-level peak current limiting and six state commutation. At the beginning of each commutation state, peak motor current is limited to less than its steady state peak value for a selected number of pulses. The peak current target then returns its normal level for the remainder of the commutation state. By reducing the peak current target for several pulses after each commutation state change, the effective supply current spike at commutation is reduced or eliminated.