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:
Oct. 17, 2000
Filed:
Apr. 15, 1999
John J Price, Edina, MN (US);
Donald J Schulte, Eagan, MN (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
A simulation circuit has a simulation circuit path that simulates operation of the write current circuit path of a write current driver. A simulation transistor simulates operation of the driver transistor and a monitor circuit monitors current at the base of the simulation transistor to derive a compensation current based on variations in base current, including breakdown of the simulation transistor. The compensation current is combined with the driver current to derive the write driver current for the driver transistor of the write current driver. In another form, the simulation circuit path is a scaled-down electrical equivalency of the write current circuit path so that the simulation current is a scaled fraction of the write current and power requirements are reduced. In one form, current is added to the compensation current to accommodate unidirectional nature of current mirrors in the monitor circuit.