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:
Apr. 02, 2002
Filed:
Jul. 12, 2001
Philip R. Cooke, San Jose, CA (US);
Richard Redl, Farvagny-le-Petit, CH;
Analog Devices, Inc., Norwood, MA (US);
Abstract
A switching voltage regulator employs a “dual modulation” scheme to control the regulator's switching components. A control circuit indirectly monitors load current. When the load decreases, the control circuit reduces both the duty ratio and the frequency of the control signals which operate the switching transistors, thereby maintaining a high efficiency level over a wider output current range than can be achieved with fixed-frequency control signals. In a preferred embodiment, the regulator employs three operating modes. For heavy loads, the switching components are operated at a constant frequency. For moderate-to-light loads, the dual modulation control scheme is used. For light loads, the regulator enters a “pulse-skipping” mode which can achieve very low operating frequencies to further improve efficiency. The invention may be used with switching regulators using peak current mode, average current mode, or voltage mode control, as well as buck, buck-boost, and boost power stages.