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. 10, 2012
Filed:
Oct. 21, 2008
Ta-yung Yang, Milpitas, CA (US);
Chuh-ching LI, Taoyuan County, TW;
Ying-chieh Su, Taipei County, TW;
Chih-chi Chang, Taoyuan County, TW;
Ta-Yung Yang, Milpitas, CA (US);
Chuh-Ching Li, Taoyuan County, TW;
Ying-Chieh Su, Taipei County, TW;
Chih-Chi Chang, Taoyuan County, TW;
System General Corp., Taipei Hsien, TW;
Abstract
A control circuit is developed to adaptively operate a power converter at quasi-resonance (QR) and in a continuous current mode (CCM) to achieve high efficiency. The control circuit includes a PWM circuit generating a switching signal coupled to switch a transformer. A signal generation circuit generates a ramp signal and a pulse signal. The pulse signal is generated in response to the ramp signal for switching on the switching signal. A feedback circuit produces a feedback signal according to an output load of the power converter. The feedback signal is coupled to switch off the switching signal. A detection circuit is coupled to the transformer for generating a valley signal in response to the waveform of the transformer. The valley signal is further coupled to generate the pulse signal when the ramp signal is lower than a threshold. The level of the threshold is correlated to the feedback signal.