DC-DC converter and organic light emitting display device using the same
First Claim
1. An organic light emitting display device, comprising:
- a display panel that has a plurality of pixels, and displays a gray scale according to the luminance of an organic light emitting diode in each pixel;
a timing controller that provides the display panel with scan and data signals for allowing the organic light emitting diode in each pixel to emit light; and
a DC-DC converter that receives an input voltage, which is supplied at an input node, so as to generate first and second voltages for supplying current to the organic light emitting diode and to provide the first and second voltages to the display panel, wherein the DC-DC converter comprises;
a first converting module that receives the input voltage to generate the first voltage and to output the first voltage at a first output node;
a second converting module that receives the input voltage to generate the second voltage and to output the second voltage at a second output node; and
a sensing unit that senses driving current supplied to the display panel, the sensing unit including a third switch, wherein the first converting module comprises;
a switching module that has a plurality of switches, the switching module converting the input voltage into the first voltage and outputting the first voltage at the first output node, each of the plurality of switches being turned on or off in response to a corresponding PWM signal; and
a control module that controls a switching operation of the switching module by generating the PWM signal, wherein the control module is configured to adaptively control the frequency of the PWM signal according to the sensed result of the sensing unit, wherein the switching module includes a second switch connected between the input node and the first output node to form or block a current path, the third switch of the sensing unit connected between the second switch and the first output node, the second switch and third switch of the sensing unit being connected in series, wherein the control module increases the frequency of the PWM signal when the driving current increases, and decreases the frequency of the PWM signal when the driving current decreases.
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Abstract
There are provided a DC-DC converter and an organic light emitting display device using the same. A DC-DC converter includes a converting module and a sensing unit. The converting module includes a switching module and a control module. The switching module has a plurality of switches, and each of the plurality of switches converts an input voltage into a first voltage and outputs the first voltage while being turned on/off in response to a corresponding pulse width modulation (PWM) signal. The control module controls a switching operation of the switching module by generating the PWM signal. The sensing unit senses driving current supplied to a load to which the first voltage is provided.
26 Citations
10 Claims
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1. An organic light emitting display device, comprising:
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a display panel that has a plurality of pixels, and displays a gray scale according to the luminance of an organic light emitting diode in each pixel; a timing controller that provides the display panel with scan and data signals for allowing the organic light emitting diode in each pixel to emit light; and a DC-DC converter that receives an input voltage, which is supplied at an input node, so as to generate first and second voltages for supplying current to the organic light emitting diode and to provide the first and second voltages to the display panel, wherein the DC-DC converter comprises; a first converting module that receives the input voltage to generate the first voltage and to output the first voltage at a first output node; a second converting module that receives the input voltage to generate the second voltage and to output the second voltage at a second output node; and a sensing unit that senses driving current supplied to the display panel, the sensing unit including a third switch, wherein the first converting module comprises; a switching module that has a plurality of switches, the switching module converting the input voltage into the first voltage and outputting the first voltage at the first output node, each of the plurality of switches being turned on or off in response to a corresponding PWM signal; and a control module that controls a switching operation of the switching module by generating the PWM signal, wherein the control module is configured to adaptively control the frequency of the PWM signal according to the sensed result of the sensing unit, wherein the switching module includes a second switch connected between the input node and the first output node to form or block a current path, the third switch of the sensing unit connected between the second switch and the first output node, the second switch and third switch of the sensing unit being connected in series, wherein the control module increases the frequency of the PWM signal when the driving current increases, and decreases the frequency of the PWM signal when the driving current decreases. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An organic light emitting display device, comprising:
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a display panel that has a plurality of pixels, and displays a gray scale according to the luminance of an organic light emitting diode in each pixel; a timing controller that provides the display panel with scan and data signals for allowing the organic light emitting diode in each pixel to emit light; and a DC-DC converter that receives an input voltage so as to generate first and second voltages for supplying current to the organic light emitting diode and to provide the first and second voltages to the display panel, wherein the DC-DC converter comprises; a first converting module that receives the input voltage so as to generate the first voltage; a second converting module that receives the input voltage so as to generate the second voltage; and a sensing unit that senses driving current supplied to the display panel, wherein each of the first and second converting modules comprises; a switching module that has a plurality of switches, each of the plurality of switches converting an input voltage into a first voltage and outputting the first voltage while being turned on or off in response to a corresponding PWM signal; and a control module that controls a switching operation of the switching module by generating the PWM signal, wherein at least one of the control modules of the first and second converting modules is configured to adaptively control the frequency of the PWM signal according to the sensed result of the sensing unit, wherein said at least one of the control modules of the first and second converting modules increases the frequency of the PWM signal when the driving current increases, and decreases the frequency of the PWM signal when the driving current decreases, wherein the switching module of the first converting module comprises; a first inductor coupled between the input node and a first node; a first switch coupled between the first node and a ground so as to form or block a current path; and a second switch coupled between the first node and a second node so as to form or block a current path, wherein the control module of the first converting module comprises; a first PWM signal generating unit that generates a first PWM signal having a frequency determined according to the sensed result of the sensing unit; and a first switch driving unit that controls the first and second switches, wherein the switching module of the second converting module comprises; a third switch coupled between the input node and a third node so as to form or block a current path; a second inductor coupled between the third node and a ground; and a fourth switch coupled between the third node and a fourth node so as to form or block a current path, wherein the control module of the second converting module comprises; a second PWM signal generating unit that generates a second PWM signal having a frequency determined according to the sensed result of the sensing unit; and a second switch driving unit that controls the third and fourth switches. - View Dependent Claims (8, 9, 10)
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Specification