Switch control method, switch controller, and converter comprising the switch controller
AssigneeFairchild Korea Semiconductor Ltd.
InventorsSang-Cheol Moon, Hyun-Chul Eom
Life of this patent
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Abstract
The present invention relates to a converter, a switch controller controlling the switching operation of a power switch in the converter, and a switch control method. An exemplary embodiment of the present invention generates a reference current corresponding to an output current of the converter and generates a control voltage that depends on the reference current. The exemplary embodiment controls an increase or a decrease of the control voltage and determines a switching frequency of the power switch according to the control voltage. The exemplary embodiment controls the on-time of the power switch by using a reference voltage determined according to a control current that depends on the reference current.
Claims20
A switch controller controlling switching operation of a power switch in a converter, comprising:
- a control voltage generator generating a reference current based on a detected signal indicative of an output current of the converter, and generating a control voltage that depends on the reference current;
- a frequency controller controlling increase or decrease of the control voltage, and controlling a switching frequency of the power switch according to the reference current, the frequency controller increasing the switching frequency of the power switch when the output current increases;
- and
- an on-time controller controlling an on-time of the power switch using a reference voltage determined according to the reference current, the on-time controller increasing the on-time of the power switch when the output current decreases.
A switch control method controlling switching operation of a power switch in a converter, comprising:
- generating a reference current based on a detected signal indicative of an output current of the converter;
- increasing or decreasing of a control voltage according to the reference current;
- sensing the control voltage, and controlling the increase or the decrease of the control voltage;
- controlling a switching frequency of the power switch according to the reference current;
- controlling an on-time of the power switch using a reference voltage determined according to a control current that depends on the reference current;
- increasing the switching frequency of the power switch when the output current increases;
- and
- increasing the on-time of the power switch when the output current decreases.
A converter comprising:
- a transformer transmitting power from a primary side to a secondary side;
- a power switch connected to a coil in the primary side of the transformer;
- a feedback unit synchronizing a reference current of the primary side according to an output current of the secondary side;
- and
- a switch controller generating a reference current based on a detected signal indicative of the output current, controlling a switching frequency of the power switch according to the reference current, controlling an on-time of the power switch using a reference voltage determined according to a control current that depends on the reference current, increasing the switching frequency of the power switch when the output current is increasing, and increasing the on-time of the power switch when the output current is decreasing.
Dependencies are inferred from the claim text.