Abstract: A spread spectrum modulation technique uses digital control logic to switch back and forth between two feedback divider ratios so that the PLL spreads output clock frequency between two limits determined by the ratios. The spread spectrum control logic can be integrated into any PLL frequency synthesizer.
Type:
Grant
Filed:
September 8, 1998
Date of Patent:
February 26, 2002
Assignee:
Fairchild Semiconductor Corporation
Inventors:
Zaw M. Soe, Ewunnet Gebre-Selassie, Mingde Pan
Abstract: A variable maximum operating temperature for a printhead is defined and utilized within both a system and a method. The variable maximum operating temperature varies according to one or more operating conditions within a printer into which the printhead may be installed. If a detected temperature of the printhead is greater than the variable maximum operating temperature for a detected operating condition, the printer will be shut down to prevent overheating. Accordingly, the system and method extend the useful life of the printhead and reduce paper waste.
Type:
Grant
Filed:
July 21, 1998
Date of Patent:
August 21, 2001
Assignee:
Hewlett-Packard Company
Inventors:
Stefano Schiaffino, Sebastia Castelltort, David H. Donovan