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:
Jun. 26, 2001
Filed:
Sep. 09, 1999
Giuseppe Patti, San Jose, CA (US);
Roberto Alini, Pleasanton, CA (US);
Gilles P. DeNoyer, Campbell, CA (US);
STMicroelectronics, Inc., Carrollton, TX (US);
Abstract
A method and circuit is disclosed for controlling the write head of a magnetic disk storage device. The circuit includes a pull-up device coupled to a terminal of the write head, for selectively providing a current to the write head through the terminal. The circuit further includes parallel-connected first and second current sink circuits, each of which is coupled to the write head terminal and selectively activated to draw current from the write head via the write head terminal. The circuit further includes a control circuit for individually activating the pull-up device and the first and second current sink circuits. In particular, when reversing the direction of current flow through the write head from a first direction in which current is provided to the write head via the write head terminal to a second direction in which current is drawn from the write head from the write head terminal, both the first and second current sink circuits are activated by the control circuit. When the current in the write head nears the desired destination current level, the second current sink circuit is deactivated and the pull-up device is thereafter immediately activated for a predetermined period of time. The pull-up device is deactivated as the current in the write head approaches a constant value. Due to the deactivation of the second current sink circuit and the temporary activation of the pull-up device, current overshoot and undershoot of the write head current is minimized.