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:
Oct. 16, 2012
Filed:
Dec. 16, 2009
Yong LI, San Jose, CA (US);
Jun Zheng, Shenzhen, CN;
Junjie Zheng, Santa Clara, CA (US);
John William Kesterson, San Jose, CA (US);
Yong Li, San Jose, CA (US);
Jun Zheng, Shenzhen, CN;
Junjie Zheng, Santa Clara, CA (US);
John William Kesterson, San Jose, CA (US);
iWatt Inc., Campbell, CA (US);
Abstract
A controller of an AC/DC flyback switching power supply uses adaptive digital control approaches to control the switching operation of a BJT power switch based on primary-side feedback to regulate the secondary-side constant output voltage and output current, without using the input line voltage. Switching-cycle by switching-cycle peak current control and limit are achieved based on the sensed primary-side current rather than the input line voltage in both constant-voltage and constant-current modes, operating in PWM, PFM and/or combinations of a plurality of PWM and PFM modes. The controller IC does not need a separate pin and ADC circuitry for sensing the input line voltage. The controller IC directly drives the BJT base, and dynamically adjusts the BJT base current amplitude cycle by cycle based on load change.