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:
May. 30, 2000
Filed:
May. 28, 1999
Wayne Anderson, Jr, Dacula, GA (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A two-stage power supply start up circuit is provided for pulse width modulator controllers that operate at a low steady state voltage. The invention provides for high-energy storage in low-capacitance start up capacitors by cascading switched start up stages, thereby allowing for the utilization of smaller, less expensive components. The invention utilizes a three-phase start up process with positive feedback ensuring both reliable start-up and steady state operation. The three phases are as 'first phase start-up', which provides power to the control circuit, 'second phase start-up', where the control chip starts switching, and 'steady state', where the power supply runs in its normal mode.