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:
Sep. 17, 2013
Filed:
Nov. 23, 2011
Erez Sarig, Hertzeliya, IL;
Raz Reshef, Tel Aviv, IL;
Erez Sarig, Hertzeliya, IL;
Raz Reshef, Tel Aviv, IL;
Tower Semiconductor Ltd., Migdal Haemek, IL;
Abstract
A modified bootstrap circuit utilized, for example, in a high voltage DC/DC CMOS buck converter to convert a high input voltage (e.g., 24V) to a regulated voltage (e.g., 4V) for use, for example, by an LED driver circuit. The bootstrap circuit utilizes a feedback diode and a PMOS switch to avoid high reverse diode voltages across a low voltage bootstrap diode. A bootstrapped buck converter implements the bootstrap circuit to generate a high gate voltage on a high-side NMOS switch during all operating phases. The PMOS switch is controlled by the NMOS switch's output voltage to pass a system voltage (e.g., 5V) through the bootstrap diode whenever the output voltage drops low (e.g., 0V), and to shut off when the output voltage subsequently rises such that the feedback diode forward biases to pass the output voltage to the anode of the bootstrap diode.