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. 28, 2008
Filed:
Dec. 12, 2007
Matthew Weng, San Ramon, CA (US);
Matthew Weng, San Ramon, CA (US);
Micrel, Inc., San Jose, CA (US);
Abstract
A buck switching regulator receives an input voltage and provides a switching output voltage on a switch output node using a minimum on-time, variable off-time feedback control loop. The buck switching regulator includes an on-time control circuit for generating a first signal for turning off the high-side switch at the expiration of a first on-time duration or at the expiration of a maximum on-time. The first on-time duration is at least a minimum on-time and is allowed to expand to a maximum on-time when the feedback voltage remains less than a reference voltage. The maximum on-time includes a first maximum on-time and a second, extended maximum on-time. The second maximum on-time is applied when a minimum off-time was used for the high-side switch during the previous switching cycle. In another embodiment, the second maximum on-time is applied only when the switching regulator is not being current limited.