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:
Mar. 03, 2009
Filed:
Nov. 09, 2005
Tsai-fu Chang, Taichung, TW;
Liang-pin Tai, Tainan, TW;
Tsai-Fu Chang, Taichung, TW;
Liang-Pin Tai, Tainan, TW;
Richtek Technology Coporation, Hsinchu, TW;
Abstract
A pulse-width-modulation (PWM) control system with nonlinear ramp is disclosed. A nonlinear ramp generator generates a nonlinear ramp varied with the duty (V/V) in a waveform signal, which could be a logarithm ramp, an exponent ramp, a multi-piecewise-linear ramp, a power ramp or a combination of above. The slope of the ramp is not a constant due to the non-linear characteristic. The voltage Vwill vary with the input voltage V, output voltage V, and duty (V/V), therefore it will reduce the influence of the input voltage Vor output voltage Vout on the modulation gain and loop gain, even to keep the modulation gain and loop gain in constant value. As mentioned-above, the present invention improves the transient response of system, the sensitivity for variation of Vand V, thus it is capable of correcting the output voltage quickly, for supplying a more steady power output.