Burst mode operation in a DC-DC converter
First Claim
1. A converter comprising:
- a main switch;
a power supply, configured to generate an output voltage by a switching operation of the main switch and by using an input voltage, and to transmit power to a load;
a current sensor, configured to sense a current flowing to the main switch to generate a sense voltage;
a burst mode controller, configured to control a burst mode group frequency by using a first voltage corresponding to a current transmitted to the load and a sawtooth waveform signal having a first frequency; and
a PWM controller, configured to control the turn-on timing of the main switch, and to determine the turn-off of the main switch by using the first voltage and the sense voltage, thus controlling the switching operation of the main switch.
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Accused Products
Abstract
The present invention relates to a converter and a driving method thereof. The converter uses an input voltage to generate an output voltage by a main switch'"'"'s switching and applies power to a load, senses the current flowing to the main switch to generate a sense voltage, uses a first voltage corresponding to the current applied to the load and a sawtooth waveform signal having a first frequency to control a group frequency of the burst mode, controls the main switch'"'"'s turn-on timing, and uses the first voltage and the sense voltage to determine whether to turn off the main switch, thereby controlling the main switch'"'"'s switching. The converter determines the start and end of the period for switching according to the result of comparing the first voltage and the sawtooth waveform signal. Therefore, a converter for having a constant group frequency, preventing audible noise, and preventing output voltage ripple, and a driving method thereof, are provided.
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Citations
16 Claims
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1. A converter comprising:
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a main switch; a power supply, configured to generate an output voltage by a switching operation of the main switch and by using an input voltage, and to transmit power to a load; a current sensor, configured to sense a current flowing to the main switch to generate a sense voltage; a burst mode controller, configured to control a burst mode group frequency by using a first voltage corresponding to a current transmitted to the load and a sawtooth waveform signal having a first frequency; and a PWM controller, configured to control the turn-on timing of the main switch, and to determine the turn-off of the main switch by using the first voltage and the sense voltage, thus controlling the switching operation of the main switch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for driving a converter for converting an input voltage into an output voltage by a switching operation of a main switch, the method comprising:
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a) controlling a switching-on period and a switching-off period in the burst mode by using a first voltage corresponding to the output voltage and a sawtooth waveform signal having a first frequency; b) controlling the main switch to be turned on at least for a first period during the switching on period; c) sensing a first current flowing to the main switch; and d) comparing a sense voltage corresponding to the first current and a first voltage corresponding to the output voltage, and determining whether to turn off the main switch. - View Dependent Claims (13, 14, 15, 16)
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Specification