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:
Jan. 13, 2015
Filed:
Apr. 11, 2012
Pier Cavallini, Swindon, GB;
Pier Cavallini, Swindon, GB;
Dialog Semiconductor GmbH, Kirchheim/Teck-Nabern, DE;
Abstract
Circuits and methods prevent ringing of white LED drivers by adding a high voltage coil switch (CS) circuit, a high voltage edge detector circuit, and a boot strap circuit. The coil switch (CS) circuit to short the coil of a boost converter, when the current in it reaches zero during DCM, comprises a series of 2 identical HV enhancement NMOS with bulk switch system. An Edge Detector circuit senses the fast falling edge of an LX node. A Boost Strap circuit lifts the gate of coil switch circuit above the battery voltage level and turns on the coil switch. A Boost Strap (BS) system lifts the gate of CS above the VBAT level and turns on CS, wherein minimum current is required to minimize impact on efficiency.