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:
May. 13, 2008
Filed:
Aug. 25, 2006
Kenji Tomiyoshi, Chiba, JP;
Kenji Tomiyoshi, Chiba, JP;
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A regulator is provided. The regulator includes a main switch, a synchronous switch, an inductor, a sample-and-hold circuit, a ramp generator, a PWM comparator, an error amplifier, and a current sense amplifier. A current through the synchronous switch is sensed by the current sense amplifier. Also, a current sense voltage provided by the current sense amplifier is sampled when the synchronous switch is on, and held when the synchronous switch is off. The ramp generator is arranged to generate a voltage ramp that emulates the slope of the inductor current while the synchronous switch is open. Additionally, the sampled synchronous switch current is combined with the voltage ramp. The PWM comparator is arranged to provide a PWM signal by comparing the voltage ramp to a comparison signal provided by the error amplifier.