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. 12, 2005
Filed:
Oct. 31, 2003
Brian P. Erisman, Carlsbad, CA (US);
Richard Redl, Farvagny-le Petit, CH;
Brian P. Erisman, Carlsbad, CA (US);
Richard Redl, Farvagny-le Petit, CH;
Analog Devices, Inc., Norwood, MA (US);
Abstract
An inductor current emulation circuit for a switched-mode power supply (SMPS) which is arranged such that its inductor current (I) goes to zero at least once per switching cycle. The emulation circuit includes an RC integrator connected in parallel across the inductor, and a zero reset switch (ZRS) connected in parallel across the integrator's capacitor. A control circuit operates the ZRS such that it is opened when Iis non-zero, and is closed for a least a portion of the time during each switching cycle when Iis zero such that the capacitor is substantially discharged. In this way, the ZRS essentially recalibrates the emulation circuit when Iis zero. When so arranged, the voltage (V) across the capacitor emulates I. The invention may be implemented with either a discontinuous-inductor-current SMPS, or a continuous-bipolar-inductor-current SMPS.