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Researchers Submit Patent Application, "Switch Mode Power Supply, Control Circuit and Associated Control Method", for Approval

July 3, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventor Ouyang, Qian (Hangzhou, CN), filed on December 10, 2013, was made available online on June 19, 2014.

The patent's assignee is Chengdu Monolithic Power Systems Co., Ltd.

News editors obtained the following quote from the background information supplied by the inventors: "With development of electronic technology, many electronic devices such as mobile phone, personal digital assistant (PDA), tablet PC, netbook and ultrabook are widely used. While many electronic devices have to support AOAC (always on and always connected) mode, i.e., standby mode, in which an electronic device is active but draws little current. The standby time period, in another word, how long the electronic device can stay in AOAC mode is critical. As load only draws little current in AOAC mode, overall efficiency at light load is of vital importance.

"Switch mode power supply is widely used in electronic devices for power conversion due to their excellent load transient response, high efficiency, small size and easy integration. But quiescent current costs most of power and mainly effects efficiency at light load."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventor's summary information for this patent application: "It is one of the objects of the present invention to provide switch mode power supply, control circuit and associated control method to resolve one or more technical problems.

"One embodiment of the present invention discloses a control circuit for a switch mode power supply, the switch mode power supply comprises a first switch and a second switch, wherein the control circuit is configured to turn ON and turn OFF the first switch and the second switch, the switch mode power supply is configured to receive an input voltage and supply an output voltage, and wherein the control circuit comprises: a first input terminal configured to receive a voltage feedback signal representing the output voltage; and an output terminal configured to provide a first switching control signal to turn ON and turn OFF the first switch; and wherein when the switch mode power supply works in a power saving mode, the first switch is turned ON if voltage feedback signal is less than a reference signal and a current flowing through the second switch decreases less than a bias current.

"Another embodiment of the present invention discloses a switch mode power supply, wherein the switch mode power supply may comprise a first switch, a second switch and the control circuit described above.

"Yet another embodiment of the present invention discloses a control method for a switch mode power supply, the switch mode power supply comprises a first switch, a second switch and a control circuit for turning ON and turning OFF the first switch and the second switch, wherein the control method comprises: providing a zero-crossing signal based on a current flowing through the second switch; turning ON the first switch based on an output voltage of the switch mode power supply when the switch mode power supply works in a normal mode; and turning ON the first switch based on the output voltage of the switch mode power supply and the zero-crossing signal when the switch mode power supply works in a power saving mode.

"With embodiments of the present invention, it is flexible to achieve lower quiescent current and higher efficiency at light load.

BRIEF DESCRIPTION OF THE DRAWINGS

"Non-limiting and non-exhaustive embodiments are described with reference to the following drawings.

"FIG. 1 illustrates a circuit block diagram of a switch mode power supply 100 according to an embodiment of the present invention.

"FIG. 2 schematically illustrates a circuit diagram of a switch mode power supply 200 according to an embodiment of the present invention.

"FIG. 3 shows waveforms of switch mode power supply 200 when works in a power saving mode normally according to an embodiment of the present invention.

"FIG. 4 shows waveforms of switch mode power supply 200 when works in the power saving mode with short circuit or over current condition according to an embodiment of the present invention.

"FIG. 5 shows a flow chart illustrating a control method with reference to a switch mode power supply according to an embodiment of the present invention.

"The use of the same reference label in different drawings indicates the same or like components."

For additional information on this patent application, see: Ouyang, Qian. Switch Mode Power Supply, Control Circuit and Associated Control Method. Filed December 10, 2013 and posted June 19, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=4649&p=93&f=G&l=50&d=PG01&S1=20140612.PD.&OS=PD/20140612&RS=PD/20140612

Keywords for this news article include: Chengdu Monolithic Power Systems Co. Ltd.

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Source: Politics & Government Week


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