LED DRIVING INTEGRATED CIRCUIT AND DRIVING METHOD THEREFOR
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Abstract
Disclosed are an LED driving integrated circuit and a driving method therefor. The LED driving integrated circuit of the present invention relates to a multi-channel AC direct-type LED driving circuit, comprising: an LED array comprising first to k-th (an integer not less than 2) LED groups connected in series; a control unit comprising a plurality of (not less than 2) switches connected to the LED array and a switch control circuit for selectively opening and closing the switches; and a valley-fill circuit, which receives the rectified voltage of an alternating current (AC) voltage, for supplying first and second variant rectified voltages to the LED array. The valley fill circuit supplies the first variant rectified voltage to an input of the first LED group of the LED array, and supplies the second variant rectified voltage to any one of the inputs of the remaining LED groups except the first LED group.
19 Citations
35 Claims
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1-11. -11. (canceled)
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12. An alternating current (AC) direct type light emitting diode (LED) driving circuit comprising:
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an LED array which comprises first through n-th LED groups connected in series and operates using a phase-cut AC voltage, where “
n”
is an integer of at least 2; anda control unit connected with the LED array, the control unit comprising a multichannel switch circuit comprising first though m-th switches connected with the LED array, where “
m”
is an integer of at least 2;
a multichannel switch control circuit configured to selectively close or open each of the first through m-th switches;
a phase detector configured to receive the phase-cut rectified voltage, detect duty information indicating a phase-cut rate, and generate a duty detection signal;
a phase dimming controller configured to generate a dimming reference voltage in response to the duty detection signal; and
an analog dimming unit configured to control brightness of the LED array by controlling current flowing in each of the first through m-th switches based on the dimming reference voltage. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 28)
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24-27. -27. (canceled)
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29. An alternating current (AC) direct type light emitting diode (LED) driving circuit comprising:
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an LED array comprising first through k-th LED groups connected in series, where “
k”
is an integer of at least 2;a control unit comprising a plurality of switches connected to the LED array and a switch control circuit which selectively closes or opens the switches; and a switchable fill circuit configured to receive a rectified voltage of an AC voltage and to supply a current to the LED array, wherein the switchable fill circuit provides a first input current for an input of the first LED group of the LED array in a first period and provides a second input current for the input of the first LED group of the LED array and a third input current for an input of one of the LED groups except for the first LED group in a second period. - View Dependent Claims (30, 31, 32, 33, 34, 35)
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Specification