(54) APPARATUS AND METHOD FOR
SUPPRESSING THE INPUT CURRENT
INRUSH FOR A VOLTAGE CONVERTER IN A
C75) Inventors: Yun-Chi Chiang, Zhubei (TW);
Kwan-Jen Chu, Hsinchu (TW);
Jien-Sheng Chen, Toufen Town (TW)
(73) Assignee: Richtek Technology Corp., Hsinchu
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 275 days.
(21) Appl.No.: 11/826,207
(22) Filed: Jul. 13, 2007
(65) Prior Publication Data
US 2008/0310198 Al Dec. 18, 2008 (30) Foreign Application Priority Data Jun. 12, 2007 (TW) 96121213 A
(51) Int. CI.
H02M 3/335 (2006.01)
(52) U.S. CI 363/17; 363/65; 363/19;
(58) Field of Classification Search 363/17,
363/19, 21.01, 65, 98, 127, 21.11; 323/222, 323/224, 272, 286-288; 315/47, 94, 209 R,
315/219, 244 See application file for complete search history.
An apparatus and method are provided for suppressing the input current inrush for a voltage converter in a pre-charge stage. The voltage converter comprises a power input for receiving an input current, a power output for supplying an output voltage for a load, and an output capacitor connected to the power output. In a pre-charge stage, a current limiting device is connected between the power input and the output capacitor to limit the input current to flow therethrough, and a variable current limiting control circuit provides a control signal to the current limiting device to determine a variable maximum value for the input current.
16 Claims, 9 Drawing Sheets