DC-DC converter and display device including same

Abstract

The invention discloses a DC-DC converter and a display device including the same. The DC-DC converter includes: a main converter configured to operate to generate a panel power voltage based on an input voltage regardless of a panel current; and a slave converter configured to operate to generate a panel power voltage based on the input voltage with the master converter when the panel current is greater than the reference current. The master converter and the slave converter are connected to the first inductor.

Description

Technical Field

[0001] Embodiments of the present invention relate to a display device. More particularly, embodiments of the present invention relate to a DC-DC converter included in a display device. Background Art

[0002] Generally, a display device includes a display panel and a display panel driver. The display panel includes pixels, and the display panel driver includes a direct current (DC)-DC converter. The DC-DC converter generates a high panel power voltage and a panel power voltage lower than the high panel power voltage, and outputs the high panel power voltage and the panel power voltage to the display panel. The display panel generates a panel current, and the intensity of the brightness is determined depending on the intensity of the panel current.

[0003] According to the demand for improving brightness, the range of panel current is widened. Therefore, as the range of panel current is widened, it is necessary to improve the driving ability of the DC-DC converter. The driving ability of the DC-DC converter may mean the current that the DC-DC converter can tolerate. However, as the driving ability of the DC-DC converter increases, the internal resistance of the DC-DC converter may increase. When the internal resistance of the DC-DC converter increases, the conduction loss may increase, and unnecessary power consumption and heat generation may increase. Summary of the invention

[0004] Embodiments of the present invention provide a DC-DC converter for reducing power consumption and heat generation.

[0005] An embodiment of the present invention provides a display device including a DC-DC converter.

[0006] In an embodiment of a DC-DC converter according to the present invention, the DC-DC converter includes: a main converter configured to operate to generate a panel power voltage based on an input voltage regardless of a panel current; and a slave converter configured to operate to generate a panel power voltage based on the input voltage together with the main converter when the panel current is greater than a reference current. The main converter and the slave converter are connected to a first inductor.

[0007] In an embodiment, when the panel current is less than or equal to a reference current, the panel current may flow to the master converter, and when the panel current is greater than the reference current, the panel current may be split into the master converter and the slave converter.

[0008] In an embodiment, when the panel current is less than or equal to a reference current, the master converter may be configured to generate a first inductor current flowing in the first inductor, and when the panel current is greater than the reference current, the master converter and the slave converter may be configured to generate the first inductor current together.

[0009] In an embodiment, when the panel current is greater than the reference current, the master converter and the slave converter may be connected in parallel.

[0010] In an embodiment, when the master converter and the slave converter are connected in parallel, a combined resistance of the master converter and the slave converter may be smaller than an internal resistance of each of the master converter and the slave converter.

[0011] In an embodiment, the DC-DC converter may further include: a feedback voltage generator configured to divide the panel power voltage to generate a feedback voltage; and an error signal generator configured to generate an error signal based on a voltage difference between the feedback voltage and a reference voltage.

[0012] In an embodiment, the master converter may include a first follower configured to alternately turn on a first switching element and a second switching element to generate at least a portion of a first inductor current flowing in the first inductor, and the slave converter may include a second follower configured to alternately turn on a third switching element and a fourth switching element to generate the other portion of the first inductor current.

[0013] In an embodiment, the main converter may further include: a first switch controller configured to generate a first switching signal for controlling the first switching element, a second switching signal for controlling the second switching element, a third switching signal for controlling the third switching element and corresponding to the first switching signal, and a fourth switching signal for controlling the fourth switching element and corresponding to the second switching signal; and a first sensing current sensor configured to sense a first sensing current flowing through the first switching element and a second sensing current flowing through the third switching element, and generate a first sensing voltage corresponding to the sum of the first sensing current and the second sensing current.

[0014] In an embodiment, the main converter may further include: a first overcurrent protector, configured to determine whether the sum of the first sensing current and the second sensing current is an overcurrent to generate a first enable signal to control the first switch controller; a first adder, configured to add a ramp voltage to the first sensing voltage to generate a first sensing ramp voltage; and a first comparator, configured to compare the error signal and the first sensing ramp voltage to generate a first signal and output the first signal to the first switch controller.

[0015] In an embodiment, the first switching element may include a gate terminal receiving a first switching signal, a first terminal receiving an input voltage, and a second terminal connected to a first node, the second switching element may include a gate terminal receiving a second switching signal, a first terminal connected to the first node, and a second terminal connected to an output node, the third switching element may include a gate terminal receiving a third switching signal, a first terminal receiving an input voltage, and a second terminal connected to the first node, the fourth switching element may include a gate terminal receiving a fourth switching signal, a first terminal connected to the first node, and a second terminal connected to the output node, and the first inductor may include a first terminal connected to the first node and a second terminal connected to ground.

[0016] In an embodiment of a DC-DC converter according to the present invention, the DC-DC converter includes: a main converter configured to operate to generate a panel power voltage based on an input voltage regardless of a panel current; and a slave converter configured to operate to generate a panel power voltage based on the input voltage together with the main converter when the panel current is greater than a reference current. In a first driving mode, the main converter is connected to a first inductor and the slave converter is connected to a second inductor, and in a second driving mode, the main converter and the slave converter are connected to the first inductor.

[0017] In an embodiment, in the first driving mode and the second driving mode, when the panel current is less than or equal to the reference current, the panel current can flow to the main converter, and in the first driving mode and the second driving mode, when the panel current is greater than the reference current, the panel current can be diverted to the main converter and the slave converter.

[0018] In an embodiment, in the first driving mode and the second driving mode, when the panel current is less than or equal to the reference current, the main converter may be configured to generate a first inductor current flowing in the first inductor.

[0019] In an embodiment, in a first driving mode, when the panel current is greater than a reference current, the master converter may be configured to generate a first inductor current and the slave converter may be configured to generate a second inductor current flowing in a second inductor, and in a second driving mode, when the panel current is greater than the reference current, the master converter and the slave converter may be configured to generate the first inductor current together.

[0020] In an embodiment, in the second driving mode, when the panel current is greater than the reference current, the master converter and the slave converter may be connected in parallel.

[0021] In an embodiment, in the second driving mode, when the master converter and the slave converter are connected in parallel, a combined resistance of the master converter and the slave converter may be smaller than an internal resistance of each of the master converter and the slave converter.

[0022] In an embodiment, the DC-DC converter may further include: a feedback voltage generator configured to divide the panel power voltage to generate a feedback voltage; and an error signal generator configured to generate an error signal based on a voltage difference between the feedback voltage and a reference voltage.

[0023] In an embodiment, the master converter may include a first follower configured to alternately turn on a first switching element and a second switching element in a first driving mode to generate a first inductor current flowing in a first inductor, and alternately turn on the first switching element and the second switching element in a second driving mode to generate at least a portion of the first inductor current, and the slave converter may include a second follower configured to alternately turn on a third switching element and a fourth switching element in the first driving mode to generate a second inductor current flowing in the second inductor, and alternately turn on the third switching element and the fourth switching element in the second driving mode to generate the other portion of the first inductor current.

[0024] In an embodiment, the main converter may further include: a first switch controller configured to generate a first switching signal to control the first switching element and a second switching signal to control the second switching element in a first driving mode, and to generate a first switching signal, a second switching signal, and a third switching signal to control the third switching element and corresponding to the first switching signal and a fourth switching signal to control the fourth switching element and corresponding to the second switching signal in a second driving mode; and a first sensing current sensor configured to sense a first sensing current flowing through the first switching element and generate a first sensing voltage corresponding to the first sensing current in the first driving mode, and to sense the first sensing current and a second sensing current flowing through the third switching element and generate a first sensing voltage corresponding to the sum of the first sensing current and the second sensing current in the second driving mode, and the slave converter may further include: a second switch controller configured to generate a third switching signal and a fourth switching signal in the first driving mode; and a second sensing current sensor configured to sense the second sensing current and generate a second sensing voltage corresponding to the second sensing current in the first driving mode.

[0025] In an embodiment, the main converter may further include: a first overcurrent protector, configured to determine whether the first sensing current is an overcurrent in the first driving mode to generate a first enable signal to control the first switch controller, and to determine whether the sum of the first sensing current and the second sensing current is an overcurrent in the second driving mode to generate the first enable signal; a first adder, configured to add a ramp voltage to the first sensing voltage to generate the first sensing ramp voltage; and a first comparator, configured to compare the error signal and the first sensing ramp voltage to generate a first signal and output the first signal to the first switch controller, and the slave converter may further include: a second overcurrent protector, configured to determine whether the second sensing current is an overcurrent in the first driving mode to generate a second enable signal to control the second switch controller; a second adder, configured to add the ramp voltage to the second sensing voltage to generate the second sensing ramp voltage; and a second comparator, configured to compare the error signal and the second sensing ramp voltage to generate a second signal and output the second signal to the second switch controller.

[0026] In an embodiment, a voltage of a common node of the third switching element and the fourth switching element may be sensed so that a shut-down operation of the DC-DC converter is performed.

[0027] In an embodiment of a display device according to the invention, the display device comprises: a display panel including pixels; and a DC-DC converter as described above, configured to operate to output a panel power voltage to the display panel.

[0028] According to the DC-DC converter according to the embodiment, the DC-DC converter may include a main converter and a slave converter that operate sequentially according to the panel current. The main converter and the slave converter may be connected to the first inductor. Accordingly, the installation area, power consumption and heat generation of the DC-DC converter may be effectively reduced.

[0029] According to the DC-DC converter and the display device according to the embodiment, the DC-DC converter may include a main converter and a slave converter that operate sequentially according to the panel current. In the first driving mode, the main converter may be connected to the first inductor, and the slave converter may be connected to the second inductor, and in the second driving mode, the main converter and the slave converter may be connected to the first inductor. Accordingly, the power consumption and heat generation of the DC-DC converter can be reduced, and the DC-DC converter can be operated in the first driving mode or the second driving mode depending on the requirements of the customer. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and other features of the embodiments of the present invention will become more apparent by describing in detail embodiments thereof with reference to the accompanying drawings, in which:

[0031] Figure 1 is a block diagram illustrating a display device according to an embodiment of the present invention;

[0032] Figure 2 is a circuit diagram illustrating a pixel according to an embodiment of the present invention;

[0033] Figure 3 is a conceptual diagram illustrating the panel current;

[0034] Figure 4 is a block diagram illustrating a second converter according to an embodiment of the present invention;

[0035] Figure 5 The diagram depends on Figure 3 A graph of the panel current and the inductor current;

[0036] Figure 6 is a block diagram illustrating a second converter according to another embodiment of the present invention;

[0037] Figure 7 It is a graphic Figure 4 A diagram of a first single drive mode of a DC-DC converter;

[0038] Figure 8 It is a graphic Figure 4 FIG. 1 is a diagram of a first dual drive mode of a DC-DC converter;

[0039] Fig. 9 It is a graphic Figure 6 A diagram of a second single driving mode of a DC-DC converter;

[0040] Fig.10 It is a graphic Figure 6 FIG. 1 is a diagram of a second dual drive mode of a DC-DC converter;

[0041] Fig.11 is a diagram describing switching between a first drive mode and a second drive mode;

[0042] Fig.12 is a block diagram illustrating an electronic device; and

[0043] Fig.13 This is a diagram showing Fig.12 FIG. 1 is a diagram of an embodiment in which the electronic device is implemented as a smart phone device. DETAILED DESCRIPTION

[0044] The terms used in this article are only used to describe the purpose of specific embodiments, and are not intended to be limited. As used in this article, "one", "the (described)" and "at least one" do not represent the limitation of quantity, and unless the context clearly indicates otherwise, it is intended to include both the singular and the plural. For example, unless the context clearly indicates otherwise, "an element" has the same meaning as "at least one element". "At least one" should not be interpreted as being limited to "one". "Or" means "and / or". As used in this article, the term "and / or" includes any combination and all combinations of one or more related listed items. It will be further understood that when used in this specification, the term "includes" or "comprising" and / or its variations indicate the existence of stated features, regions, entireties, steps, operations, elements and / or parts, but does not exclude the existence or addition of one or more other features, regions, entireties, steps, operations, elements, parts and / or its groups.

[0045] It will be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, components, regions, layers and / or portions, these elements, components, regions, layers and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or portion from another element, component, region, layer or portion. Therefore, the first element, component, region, layer or portion discussed below may be referred to as a second element, component, region, layer or portion without departing from the teachings herein.

[0046] It will be understood that when an element is referred to as being "on" or "connected to" another element, it may be directly on or directly connected to the other element, or intervening elements may exist therebetween. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0047] Figure 1 is a block diagram illustrating a display device according to an embodiment of the present invention.

[0048] Reference Figure 1 The display device 10 may include a display panel 100 and a display panel driver. The display panel driver may include a driving controller 200, a gate driver 300, a gamma reference voltage generator 400, a data driver 500, and a DC-DC converter 600.

[0049] The display panel 100 may include a display area displaying an image and a peripheral area disposed adjacent to the display area.

[0050] The display panel 100 may include gate lines GL, data lines DL, and pixels P electrically connected to the gate lines GL and the data lines DL. The gate lines GL may extend in a first direction D1, and the data lines DL may extend in a second direction D2 crossing the first direction D1.

[0051] The driving controller 200 may receive input image data IMG and an input control signal CONT from an external device (not shown). For example, the input image data IMG may include red image data, green image data, and blue image data. The input image data IMG may further include white image data. The input image data IMG may include magenta image data, yellow image data, and cyan image data. The input control signal CONT may include a main clock signal and a data enable signal. The input control signal CONT may further include a vertical synchronization signal and a horizontal synchronization signal.

[0052] The driving controller 200 may generate a first control signal CONT1 , a second control signal CONT2 , a third control signal CONT3 , a fourth control signal CONT4 , and a data signal DATA based on input image data IMG and an input control signal CONT.

[0053] The driving controller 200 may generate a first control signal CONT1 for controlling the operation of the gate driver 300 based on the input control signal CONT, and output the first control signal CONT1 to the gate driver 300. The first control signal CONT1 may include a vertical start signal and a gate clock signal.

[0054] The driving controller 200 may generate a second control signal CONT2 for controlling the operation of the data driver 500 based on the input control signal CONT, and output the second control signal CONT2 to the data driver 500. The second control signal CONT2 may include a horizontal start signal and a load signal.

[0055] The driving controller 200 may generate a data signal DATA based on the input image data IMG. The driving controller 200 may output the data signal DATA to the data driver 500.

[0056] The driving controller 200 may generate a third control signal CONT3 for controlling the operation of the gamma reference voltage generator 400 based on the input control signal CONT, and output the third control signal CONT3 to the gamma reference voltage generator 400 .

[0057] The driving controller 200 may generate a fourth control signal CONT4 for controlling the operation of the DC-DC converter 600 based on the input control signal CONT, and output the fourth control signal CONT4 to the DC-DC converter 600 .

[0058] The gate driver 300 may generate a gate signal for driving the gate line GL in response to the first control signal CONT1 received from the driving controller 200. The gate driver 300 may output the gate signal to the gate line GL.

[0059] The gamma reference voltage generator 400 may generate the gamma reference voltage VGREF in response to the third control signal CONT3 received from the driving controller 200. The gamma reference voltage generator 400 may output the gamma reference voltage VGREF to the data driver 500. The gamma reference voltage VGREF may have a value corresponding to each data signal DATA.

[0060] In an embodiment, the gamma reference voltage generator 400 may be provided in the driving controller 200 or the data driver 500 .

[0061] The data driver 500 may receive the second control signal CONT2 and the data signal DATA from the driving controller 200, and receive the gamma reference voltage VGREF from the gamma reference voltage generator 400. The data driver 500 may convert the data signal DATA into a data voltage in an analog form. The data driver 500 may output the data voltage to the data line DL.

[0062] The DC-DC converter 600 may receive the fourth control signal CONT4 from the driving controller 200 and the panel current IPL from the display panel 100. The DC-DC converter 600 may include a first converter 610 and a second converter 620. The second converter 620 may include a master converter 630 and a slave converter 640. Figure 1 In the embodiment, the number of slave converters 640 is shown as one, but the present invention is not limited thereto. In another embodiment, the number of slave converters 640 may be at least two.

[0063] The first converter 610 may generate a high panel power voltage ELVDD based on an input voltage VIN received from an external device (not shown) in response to a fourth control signal CONT4. In an embodiment, the first converter 610 may be a boost converter. In this case, when the input voltage VIN is lower than the high panel power voltage ELVDD, the first converter 610 may increase the input voltage VIN to generate the high panel power voltage ELVDD. The first converter 610 may output the high panel power voltage ELVDD to the display panel 100.

[0064] The second converter 620 may generate a panel power voltage ELVSS based on the input voltage VIN in response to the fourth control signal CONT4. The panel power voltage ELVSS may be lower than the high panel power voltage ELVDD. In an embodiment, the second converter 620 may be a buck-boost converter. In this case, when the input voltage VIN is lower than the panel power voltage ELVSS, the second converter 620 may boost the input voltage VIN to generate the panel power voltage ELVSS, and when the input voltage VIN is higher than the panel power voltage ELVSS, the second converter 620 may reduce the input voltage VIN to generate the panel power voltage ELVSS. The second converter 620 may output the panel power voltage ELVSS to the display panel 100.

[0065] Figure 2 is a circuit diagram illustrating a pixel according to an embodiment of the present invention. Figure 3 is a conceptual diagram illustrating panel current.

[0066] Reference Figures 1 to 3 , the pixel P may include a first pixel switching element SP1, a second pixel switching element SP2, a storage capacitor CST, and a light emitting element EE.

[0067] The first pixel switching element SP1 may include a gate terminal connected to the first pixel node NP1 , a first terminal receiving the high panel power voltage ELVDD, and a second terminal connected to the anode of the light emitting element EE.

[0068] The second pixel switching element SP2 may include a gate terminal receiving the gate signal GS, a first terminal receiving the data voltage VDATA, and a second terminal connected to the first pixel node NP1.

[0069] The storage capacitor CST may include a first terminal receiving the high panel power voltage ELVDD and a second terminal connected to the first pixel node NP1 .

[0070] The light emitting element EE may include an anode connected to the second terminal of the first pixel switching element SP1 and a cathode receiving the panel power voltage ELVSS.

[0071] exist Figure 2 In the embodiment, the first pixel switching element SP1 and the second pixel switching element SP2 are shown as P-type transistors, but the present invention is not limited thereto. The first pixel switching element SP1 and the second pixel switching element SP2 may be N-type transistors. Figure 2 In FIG. 1 , the pixel P is shown to include two pixel switching elements SP1 and SP2 and one capacitor CST, but the present invention is not limited thereto. The pixel P may include at least three pixel switching elements or at least two capacitors.

[0072] The second pixel switching element SP2 may apply the data voltage VDATA to the first pixel node NP1 in response to the gate signal GS, the first pixel switching element SP1 may generate a driving current IEE based on the data voltage VDATA, and the driving current IEE may flow to the light emitting element EE. The light emitting element EE may emit light based on the driving current IEE, and the intensity of the brightness may be determined depending on the intensity of the driving current IEE.

[0073] The display panel 100 may include pixels P, and the driving current IEE may flow in each of the pixels P. Therefore, the driving current IEE may be a value in units of pixels P, and the panel current IPL may be a value in units of the display panel 100. That is, the driving current IEE may be referred to as a current flowing in one pixel P, and the panel current IPL may be referred to as a total current flowing in the display panel 100.

[0074] According to the demand for improving brightness, the range of panel current IPL may be widened. Therefore, as the range of panel current IPL is widened, it may be necessary to improve the driving capability of DC-DC converter 600. The driving capability of DC-DC converter 600 may mean the current that DC-DC converter 600 can tolerate. However, as the driving capability of DC-DC converter 600 is improved, the number of elements included in DC-DC converter 600 may increase, and accordingly, the internal resistance of DC-DC converter 600 may increase. When the internal resistance of DC-DC converter 600 increases, conduction loss may increase, and unnecessary power consumption and heating may increase.

[0075] For example, when the panel current IPL ranges from 0 A to 1 A, the second converter 620 may include one converter having a driving capability of 1 A. However, since the internal resistance of one converter having a driving capability of 1 A is large, for a small panel current IPL such as 0.3 A, one converter having a driving capability of 1 A may be disadvantageous in terms of power consumption and heat generation.

[0076] In order to solve this problem, the second converter 620 according to an embodiment of the present invention includes a main converter 630 and a slave converter 640. When the required panel current IPL is less than or equal to the reference current, only the main converter 630 can operate to provide the panel current IPL. When the required panel current IPL is greater than the reference current, both the main converter 630 and the slave converter 640 can operate together to provide the panel current IPL. That is, the main converter 630 can operate to generate the panel power voltage ELVSS regardless of the value of the panel current IPL, and when the panel current IPL is higher than the reference current, the slave converter 640 can operate to generate the panel power voltage ELVSS together with the main converter 630. The driving mode in which only the main converter 630 operates can be referred to as a "single driving mode", and the driving mode in which both the main converter 630 and the slave converter 640 operate can be referred to as a "dual driving mode".

[0077] In this way, when the panel current IPL is low, the second converter 620 can use only the main converter 630 which has a small driving capability but also a small internal resistance to reduce power consumption and heat generation, and when the panel current IPL is high, the second converter 620 can use both the main converter 630 and the slave converter 640 to improve the driving capability of the DC-DC converter 600.

[0078] Figure 4 is a block diagram illustrating a second converter according to an embodiment of the present invention. Figure 5 The diagram depends on Figure 3 A graph of the panel current versus the inductor current.

[0079] Reference Figure 4 and Figure 5 , Figure 4 The second converter 620a may include a main converter 630a and a slave converter 640a. The main converter 630a may be connected to the first inductor L1 through the first inductor output terminal OUT_L1, and is connected to the output capacitor CO through the first voltage output terminal OUT_V1. The main converter 630a may be connected to the first capacitor C1 and receive the input voltage VIN through the first input terminal. The slave converter 640a may be connected to the second inductor L2 through the second inductor output terminal OUT_L2, and is connected to the output capacitor CO through the second voltage output terminal OUT_V2. The slave converter 640a may be connected to the second capacitor C2 and receive the input voltage VIN through the second input terminal. That is, the main converter 630a and the slave converter 640a may not share a common inductor. Instead, the main converter 630a and the slave converter 640a may be connected to the first inductor L1 and the second inductor L2, respectively.

[0080] As such, the case where the first inductor L1 is connected to the master converter 630a and the second inductor L2 is connected to the slave converter 640a may be referred to as a “first driving mode.” The first driving mode may also be referred to as a converter sequential driving (“CSD”) driving mode.

[0081] When the first switching element and the second switching element included in the main converter 630a are alternately turned on, the first inductor current IL1 can flow in the first inductor L1, so that an electromotive force can be generated in the first inductor L1 based on the first inductor current IL1, and the input voltage VIN can be converted into the panel power voltage ELVSS based on the electromotive force.

[0082] When the third switching element and the fourth switching element included in the slave converter 640a are alternately turned on, the second inductor current IL2 may flow in the second inductor L2, so that an electromotive force may be generated in the second inductor L2 based on the second inductor current IL2, and the input voltage VIN may be converted into the panel power voltage ELVSS based on the electromotive force. When the panel current IPL is less than or equal to the reference current, the main converter 630a may be configured to generate the first inductor current IL1 flowing in the first inductor L1, and when the panel current IPL is greater than the reference current, the main converter 630a may be configured to generate the first inductor current IL1, and the slave converter 640a may be configured to generate the second inductor current IL2 flowing in the second inductor L2.

[0083] Later on Figure 7 and Figure 8 Detailed configuration and operation of the DC-DC converter 600 a in the first driving mode are described in detail. In the first driving mode, the input voltage VIN is converted into the panel power voltage ELVSS based on the electromotive force.

[0084] The single driving mode of the first driving mode may be referred to as a “first single driving mode”, and the dual driving mode of the first driving mode may be referred to as a “first dual driving mode”. In the first single driving mode, only the master converter 630a may operate, and in the first dual driving mode, both the master converter 630a and the slave converter 640a may operate.

[0085] like Figure 5 As shown in , the second converter 620a can operate in the first driving mode. When the panel current IPL is greater than the reference current IR, the inductor current IL1+IL2 flowing only in the first inductor L1 when the panel current IPL is less than or equal to the reference current IR can be divided into the first inductor L1 and the second inductor L2. Therefore, it can be advantageous in terms of power consumption and heat generation.

[0086] Figure 6 is a block diagram illustrating a second converter according to another embodiment of the present invention.

[0087] Reference Figure 6 , Figure 6 The second converter 620b may include a main converter 630b and a slave converter 640b. The main converter 630b may be connected to the first inductor L1 through the first inductor output terminal OUT_L1, and is connected to the output capacitor CO through the first voltage output terminal OUT_V1. The main converter 630b may be connected to the first capacitor C1 and receive the input voltage VIN through the first input terminal. The slave converter 640b may be connected to the first inductor L1 through the second inductor output terminal OUT_L2, and is connected to the output capacitor CO through the second voltage output terminal OUT_V2. The slave converter 640b may be connected to the second capacitor C2 and receives the input voltage VIN through the second input terminal. That is, both the main converter 630b and the slave converter 640b may be connected to the first inductor L1.

[0088] As such, the case where the first inductor L1 is commonly connected to the master converter 630a and the slave converter 640a may be referred to as a “second driving mode.” The second driving mode may also be referred to as a single inductor dual converter (“SIDC”) driving mode.

[0089] When the first switching element and the second switching element included in the main converter 630b are alternately turned on and the third switching element and the fourth switching element included in the slave converter 640b are alternately turned on, the first inductor current IL1 may flow in the first inductor L1, so that an electromotive force may be generated in the first inductor L1 based on the first inductor current IL1, and the input voltage VIN may be converted into the panel power voltage ELVSS. When the panel current IPL is less than or equal to the reference current, the main converter 630b may be configured to generate the first inductor current IL1 flowing in the first inductor L1, and when the panel current IPL is greater than the reference current, the main converter 630b and the slave converter 640b may be configured to generate the first inductor current IL1 together.

[0090] Will refer to later Fig. 9 and Fig.10 A detailed configuration and operation of the DC-DC converter 600 b in the second driving mode in which the input voltage VIN is converted into the panel power voltage ELVSS based on an electromotive force is described.

[0091] The single drive mode of the second drive mode may be referred to as the second single drive mode, and the dual drive mode of the second drive mode may be referred to as the second dual drive mode. In the second single drive mode, only the main converter 630b may operate, and in the second dual drive mode, both the main converter 630b and the slave converter 640b may operate.

[0092] exist Figures 4 to 6 , the master converter 630 and the slave converter 640 are shown as being included in the second converter 620, but the present invention is not limited thereto. The first converter 610 may also include a master converter and at least one slave converter.

[0093] The first drive mode is Figure 4 and Figure 5 and the second drive mode is Figure 6 A case where the second converter 620 operates in the first driving mode or the second driving mode will be described later.

[0094] The second converter 620 may be operated in the first drive mode or the second drive mode depending on the electronic device (e.g., mobile phone, computer monitor). The installation area of ​​the DC-DC converter 600, the driving capability of the DC-DC converter 600, etc. may vary depending on the electronic device. Depending on the above conditions, the second converter 620 may be configured and operated in the first drive mode or the second drive mode.

[0095] In the second driving mode, since the main converter 630b and the slave converter 640b are connected to the first inductor L1 (that is, the DC-DC converter 600b does not include the second inductor L2), the installation area of ​​the DC-DC converter 600b in the second driving mode can be less than the installation area of ​​the DC-DC converter 600a in the first driving mode. In the second driving mode, since the main converter 630b and the slave converter 640b are connected in parallel to each other, the synthetic resistance of the main converter 630b and the slave converter 640b can be approximately half of the internal resistance of each of the main converters 630a and 630b and the slave converters 640a and 640b. Accordingly, in terms of power consumption and heating, the second driving mode can be more advantageous than the first driving mode. However, in terms of the driving capability of the DC-DC converter, the second driving mode may be more disadvantageous than the first driving mode. Thus, for example, when the panel current IPL ranges from 0A to 1A, the first driving mode may be more advantageous than the second driving mode, and when the panel current IPL ranges from 0A to 0.7A, the second driving mode may be more advantageous than the first driving mode.

[0096] In the first driving mode and the second driving mode, when the panel current IPL is less than or equal to the reference current, the panel current IPL may flow to the main converter 630, and when the panel current IPL is greater than the reference current, the panel current IPL may be split into the main converter 630 and the slave converter 640. The general configuration and operation of the main converter 630 and the slave converter 640 according to the first driving mode or the second driving mode have been described, and the specific configuration and operation of the main converter 630 and the slave converter 640 will be described later.

[0097] Figure 7 It is a graphic Figure 4 Diagram of the first single drive mode of the DC-DC converter. Figure 8 It is a graphic Figure 4 Diagram of the first dual-drive mode of the DC-DC converter. Figure 7 , Fig. 9 and Fig.10 The hatched area in the figure indicates that the components in the area are not operational.

[0098] Reference Figure 7 and Figure 8 In the first driving mode, the DC-DC converter 600a may include a main converter 630a and a slave converter 640a, wherein the main converter 630a generates a panel power voltage ELVSS based on the input voltage VIN regardless of the panel current IPL, and the slave converter 640a generates the panel power voltage ELVSS based on the input voltage VIN when the panel current IPL is greater than the reference current IR.

[0099] The master converter 630a may be connected to the first capacitor C1 through the first input terminal IN_C1, to the first inductor L1 through the first inductor output terminal OUT_L1, and to the output capacitor CO through the first voltage output terminal OUT_V1. The slave converter 640a may be connected to the second capacitor C2 through the second input terminal IN_C2, to the second inductor L2 through the second inductor output terminal OUT_L2, and to the output capacitor CO through the second voltage output terminal OUT_V2. The output capacitor CO may be connected to the output node ELVSS_ON to stabilize the output of the panel power voltage ELVSS.

[0100] The DC-DC converter 600a may further include a feedback voltage generator 650 that divides the panel power voltage ELVSS to generate a feedback voltage VFB and an error signal generator 660 that generates an error signal VERR based on a voltage difference between the feedback voltage VFB and a reference voltage VREF. The feedback voltage generator 650 may include a first resistor R1 and a second resistor R2. The feedback voltage generator 650 may be connected between the output node ELVSS_ON and the ground. The error signal generator 660 may include an error amplifier 665 that generates an error signal VERR based on a voltage difference between the feedback voltage VFB and the reference voltage VREF, a third resistor R3, and a third capacitor C3. The third resistor R3 and the third capacitor C3 may be connected in series between the output terminal of the error amplifier 665 and the ground.

[0101] The master converter 630a may include a first outputter 631 that alternately turns on the first switching element S1 and the second switching element S2 to generate a first inductor current IL1 flowing in the first inductor L1. The slave converter 640a may include a second outputter 641 that alternately turns on the third switching element S3 and the fourth switching element S4 to generate a second inductor current IL2 flowing in the second inductor L2. The first outputter 631 may further include a first buffer B1 connected to the first switching element S1 and a second buffer B2 connected to the second switching element S2, and the second outputter 641 may further include a third buffer B3 connected to the third switching element S3 and a fourth buffer B4 connected to the fourth switching element S4. The first switching element S1 may be turned on based on the first switching signal PWM1, and the second switching element S2 may be turned on based on the second switching signal PWM2. When the first switching element S1 is turned on and the second switching element S2 is turned off, the first inductor current IL1 may flow in the first inductor L1, so that an electromotive force may be generated in the first inductor L1. When the first switching element S1 is turned off and the second switching element S2 is turned on after the electromotive force is generated in the first inductor L1, the input voltage VIN can be converted into the panel power voltage ELVSS. The third switching element S3 can be turned on based on the third switching signal PWM3, and the fourth switching element S4 can be turned on based on the fourth switching signal PWM4. When the third switching element S3 is turned on and the fourth switching element S4 is turned off, the second inductor current IL2 can flow in the second inductor L2, so that the electromotive force can be generated in the second inductor L2. When the third switching element S3 is turned off and the fourth switching element S4 is turned on after the electromotive force is generated in the second inductor L2, the input voltage VIN can be converted into the panel power voltage ELVSS. Each of the first switching signal PWM1, the second switching signal PWM2, the third switching signal PWM3 and the fourth switching signal PWM4 can be a pulse width modulation ("PWM") signal.

[0102] The first switching element S1 may include a gate terminal receiving a first switching signal PWM1, a first terminal receiving an input voltage VIN, and a second terminal connected to a first node N1. The second switching element S2 may include a gate terminal receiving a second switching signal PWM2, a first terminal connected to the first node N1, and a second terminal connected to an output node ELVSS_ON. The third switching element S3 may have a gate terminal receiving a third switching signal PWM3, a first terminal receiving an input voltage VIN, and a second terminal connected to a second node N2. The fourth switching element S4 may include a gate terminal receiving a fourth switching signal PWM4, a first terminal connected to a second node N2, and a second terminal connected to the output node ELVSS_ON. The first inductor L1 may include a first terminal connected to the first node N1 and a second terminal connected to ground. The second inductor L2 may include a first terminal connected to the second node N2 and a second terminal connected to ground.

[0103] The master converter 630a may further include: a first switch controller 632, generating a first switching signal PWM1 for controlling the first switching element S1 and a second switching signal PWM2 for controlling the second switching element S2; and a first sensing current sensor 633, sensing a first sensing current ISENS1 flowing through the first switching element S1, and generating a first sensing voltage VSENS1 corresponding to the first sensing current ISENS1. The first sensing current ISENS1 may be a current corresponding to the first inductor current IL1. The slave converter 640a may further include: a second switch controller 642, generating a third switching signal PWM3 for controlling the third switching element S3 and a fourth switching signal PWM4 for controlling the fourth switching element S4; and a second sensing current sensor 643, sensing a second sensing current ISENS2 flowing through the third switching element S3, and generating a second sensing voltage VSENS2 corresponding to the second sensing current ISENS2. The second sensing current ISENS2 may be a current corresponding to the second inductor current IL2.

[0104] The main converter 630a may further include: a first overcurrent protector 634, determining whether the first sense current ISENS1 is an overcurrent to generate a first enable signal EN_SW1 for controlling the first switch controller 632; a first adder 635, adding the slope voltage VSLP to the first sense voltage VSENS1 to generate the first sense slope voltage VSLP1; and a first comparator 636, comparing the error signal VERR with the first sense slope voltage VSLP1 to generate a first signal CS1 and outputting the first signal CS1 to the first switch controller 632. The first signal CS1 may be used to generate the first switching signal PWM1 and the second switching signal PWM2. The slave converter 640a may further include: a second overcurrent protector 644, determining whether the second sense current ISENS2 is an overcurrent to generate a second enable signal EN_SW2 for controlling the second switch controller 642; a second adder 645, adding the ramp voltage VSLP to the second sense voltage VSENS2 to generate the second sense ramp voltage VSLP2; and a second comparator 646, comparing the error signal VERR with the second sense ramp voltage VSLP2 to generate a second signal CS2 and outputting the second signal CS2 to the second switch controller 642. The second signal CS2 may be used to generate a third switch signal PWM3 and a fourth switch signal PWM4.

[0105] When the first sensing current ISENS1 is an overcurrent, the first overcurrent protector 634 may turn off the first switch controller 632, and when the second sensing current ISENS2 is an overcurrent, the second overcurrent protector 644 may turn off the second switch controller 642. The ramp voltage VSLP may be a sawtooth wave. Accordingly, the first sensing ramp voltage VSLP1 and the second sensing ramp voltage VSLP2 may be sawtooth waves.

[0106] As described above, in the first single driving mode, only the master converter 630 a may operate, and in the first dual driving mode, both the master converter 630 a and the slave converter 640 a may operate.

[0107] Fig. 9 It is a graphic Figure 6 Diagram of the second single drive mode of the DC-DC converter. Fig.10 It is a graphic Figure 6 Diagram of the second dual-drive mode of the DC-DC converter. Fig.11 is a diagram describing switching between the first drive mode and the second drive mode.

[0108] Reference Figures 9 to 11In the second driving mode, the DC-DC converter 600b may include a main converter 630b and a slave converter 640b, wherein the main converter 630b generates a panel power voltage ELVSS based on the input voltage VIN regardless of the panel current IPL, and the slave converter 640b generates a panel power voltage ELVSS based on the input voltage VIN when the panel current IPL is greater than the reference current IR.

[0109] The master converter 630b may be connected to the first capacitor C1 through the first input terminal IN_C1, to the first inductor L1 through the first inductor output terminal OUT_L1, and to the output capacitor CO through the first voltage output terminal OUT_V1. The slave converter 640b may be connected to the second capacitor C2 through the second input terminal IN_C2, to the first inductor L1 through the second inductor output terminal OUT_L2, and to the output capacitor CO through the second voltage output terminal OUT_V2. The output capacitor CO may be connected to the output node ELVSS_ON to stabilize the output of the panel power voltage ELVSS.

[0110] The DC-DC converter 600b may further include a feedback voltage generator 650 that divides the panel power voltage ELVSS to generate a feedback voltage VFB and an error signal generator 660 that generates an error signal VERR based on a voltage difference between the feedback voltage VFB and a reference voltage VREF. The feedback voltage generator 650 may include a first resistor R1 and a second resistor R2. The feedback voltage generator 650 may be connected between the output node ELVSS_ON and the ground. The error signal generator 660 may include an error amplifier 665 that generates an error signal VERR based on a voltage difference between the feedback voltage VFB and the reference voltage VREF, a third resistor R3, and a third capacitor C3. The third resistor R3 and the third capacitor C3 may be connected in series between the output terminal of the error amplifier 665 and the ground.

[0111] The master converter 630b may include a first output 631 that alternately turns on the first switching element S1 and the second switching element S2 to generate at least a portion of the first inductor current IL1 flowing in the first inductor L1. The slave converter 640b may include a second output 641 that alternately turns on the third switching element S3 and the fourth switching element S4 to generate the other portion of the first inductor current IL1. The first output 631 may further include a first buffer B1 connected to the first switching element S1 and a second buffer B2 connected to the second switching element S2, and the second output 641 may further include a third buffer B3 connected to the third switching element S3 and a fourth buffer B4 connected to the fourth switching element S4. The first switching element S1 may be turned on based on the first switching signal PWM1, and the second switching element S2 may be turned on based on the second switching signal PWM2. When the first switching element S1 is turned on and the second switching element S2 is turned off, the first inductor current IL1 may flow in the first inductor L1, so that an electromotive force may be generated in the first inductor L1. When the first switching element S1 is turned off and the second switching element S2 is turned on after the electromotive force is generated in the first inductor L1, the input voltage VIN may be converted into the panel power voltage ELVSS. The third switching element S3 may be turned on based on the third switching signal PWM3, and the fourth switching element S4 may be turned on based on the fourth switching signal PWM4. The third switching signal PWM3 may correspond to the first switching signal PWM1. Specifically, except that in the second single drive mode, the first switching signal PWM1 is activated and the third switching signal PWM3 is deactivated, and in the second dual drive mode, the first switching signal PWM1 and the third switching signal PWM3 are activated, the third switching signal PWM3 may be substantially equal to the first switching signal PWM1. The fourth switching signal PWM4 may correspond to the second switching signal PWM2. Specifically, except that in the second single drive mode, the second switch signal PWM2 is activated and the fourth switch signal PWM4 is deactivated, and in the second dual drive mode, the second switch signal PWM2 and the fourth switch signal PWM4 are activated, the fourth switch signal PWM4 may be substantially equal to the second switch signal PWM2. When the third switch element S3 is turned on and the fourth switch element S4 is turned off, the first inductor current IL1 may flow in the first inductor L1, so that an electromotive force may be generated in the first inductor L1. When the third switch element S3 is turned off and the fourth switch element S4 is turned on after the electromotive force is generated in the first inductor L1, the input voltage VIN may be converted into the panel power voltage ELVSS. Each of the first switch signal PWM1, the second switch signal PWM2, the third switch signal PWM3, and the fourth switch signal PWM4 may be a PWM signal.

[0112] The first switching element S1 may include a gate terminal receiving a first switching signal PWM1, a first terminal receiving an input voltage VIN, and a second terminal connected to a first node N1. The second switching element S2 may include a gate terminal receiving a second switching signal PWM2, a first terminal connected to the first node N1, and a second terminal connected to an output node ELVSS_ON. The third switching element S3 may include a gate terminal receiving a third switching signal PWM3, a first terminal receiving an input voltage VIN, and a second terminal connected to the first node N1. The fourth switching element S4 may include a gate terminal receiving a fourth switching signal PWM4, a first terminal connected to the first node N1, and a second terminal connected to the output node ELVSS_ON. The first inductor L1 may include a first terminal connected to the first node N1 and a second terminal connected to ground.

[0113] The main converter 630b may further include: a first switch controller 632, generating a first switching signal PWM1 for controlling the first switching element S1, a second switching signal PWM2 for controlling the second switching element S2, a third switching signal PWM3 for controlling the third switching element S3, and a fourth switching signal PWM4 for controlling the fourth switching element S4; and a first sensing current sensor 633, sensing a first sensing current ISENS1 flowing through the first switching element S1 and a second sensing current ISENS2 flowing through the third switching element S3, and generating a first sensing voltage VSENS1 corresponding to the sum of the first sensing current ISENS1 and the second sensing current ISENS2. The sum of the first sensing current ISENS1 and the second sensing current ISENS2 may be a current corresponding to the first inductor current IL1.

[0114] The main converter 630b may further include: a first overcurrent protector 634, determining whether the sum of the first sensing current ISENS1 and the second sensing current ISENS2 is an overcurrent to generate a first enable signal EN_SW1 for controlling the first switch controller 632; a first adder 635, adding the slope voltage VSLP to the first sensing voltage VSENS1 to generate the first sensing slope voltage VSLP1; and a first comparator 636, comparing the error signal VERR with the first sensing slope voltage VSLP1 to generate a first signal CS1 and outputting the first signal CS1 to the first switch controller 632. The first signal CS1 may be used to generate the first switching signal PWM1, the second switching signal PWM2, the third switching signal PWM3, and the fourth switching signal PWM4.

[0115] When the sum of the first sensing current ISENS1 and the second sensing current ISENS2 is an overcurrent, the first overcurrent protector 634 may turn off the first switch controller 632. The ramp voltage VSLP may be a sawtooth wave. Accordingly, the first sensing ramp voltage VSLP1 may be a sawtooth wave.

[0116] As described above, in the second single driving mode, only the master converter 630 b may operate, and in the second dual driving mode, both the master converter 630 b and the slave converter 640 b may operate.

[0117] In an embodiment, Figures 7 to 10 As shown in FIG. 1 , the DC-DC converter 600 a in the first driving mode and the DC-DC converter 600 b in the second driving mode can be designed and manufactured separately in process steps.

[0118] In another embodiment, if Fig.11 As shown in , both the DC-DC converter 600a in the first driving mode and the DC-DC converter 600b in the second driving mode can be designed and manufactured in the process steps. In this case, after manufacturing, the DC-DC converter 600a in the first driving mode or the DC-DC converter 600b in the second driving mode can be selected depending on the requirements of the customer (i.e., the electronic device), and the connection relationship of some elements of the DC-DC converter 600 can be changed. For example, Fig.11As shown in , the second converter 620 may further include a first switch SW1 to an eighth switch SW8. The first switch SW1 may be disposed between the second inductor L2 and the second inductor output terminal OUT_L2, the second switch SW2 may be disposed between the first inductor L1 and the second inductor output terminal OUT_L2, the third switch SW3 may be disposed between the second switch controller 642 and the fourth buffer B4, the fourth switch SW4 may be disposed between the first switch controller 632 and the fourth buffer B4, the fifth switch SW5 may be disposed between the second switch controller 642 and the third buffer B3, and the sixth switch SW6 may be disposed between the first switch controller 632 and the third buffer B3. The seventh switch SW7 and the eighth switch SW8 determine whether the first sensing current sensor 633 receives only the first sensing current ISENS1 or receives both the first sensing current ISENS1 and the second sensing current ISENS2. In the first driving mode, the first switch SW1, the third switch SW3, the fifth switch SW5, and the seventh switch SW7 may be turned on, and the second switch SW2, the fourth switch SW4, the sixth switch SW6, and the eighth switch SW8 may be turned off. In the second driving mode, the first switch SW1 , the third switch SW3 , the fifth switch SW5 , and the seventh switch SW7 may be turned off, and the second switch SW2 , the fourth switch SW4 , the sixth switch SW6 , and the eighth switch SW8 may be turned on.

[0119] In addition, in the second dual driving mode, the second switch controller 642, the second sensing current sensor 643, the second overcurrent protector 644, the second adder 645 and the second comparator 646 may be turned off, and the second output 641 may be turned on. The operations of the second switch controller 642, the second sensing current sensor 643, the second overcurrent protector 644, the second adder 645 and the second comparator 646 may be performed by the first switch controller 632, the first sensing current sensor 633, the first overcurrent protector 634, the first adder 635 and the first comparator 636. Therefore, as described above, the first switch controller 632 may generate the third switching signal PWM3 and the fourth switching signal PWM4.

[0120] When the DC-DC converter 600a in the first driving mode and the DC-DC converter 600b in the second driving mode are designed and manufactured separately in the process steps, since the DC-DC converter 600b in the second driving mode does not include the second inductor L2, the installation area of ​​the DC-DC converter 600b can be reduced.

[0121] When both the DC-DC converter 600a in the first driving mode and the DC-DC converter 600b in the second driving mode can be designed and manufactured in a process step, even after manufacturing, the DC-DC converter 600 can be selected as the DC-DC converter 600a in the first driving mode or the DC-DC converter 600b in the second driving mode depending on the customer's requirements (i.e., electronic device).

[0122] When the DC-DC converter 600 is selected as the DC-DC converter 600a in the first driving mode, the hardware and software of the DC-DC converter 600 can be set to the first driving mode, and when the DC-DC converter 600 is selected as the DC-DC converter 600b in the second driving mode, the hardware and software of the DC-DC converter 600 can be set to the second driving mode. However, despite the customer's requirements, the driving mode of the hardware of the DC-DC converter 600 and the driving mode of the software of the DC-DC converter 600 may not match due to setting errors. For example, the hardware of the DC-DC converter 600 may be in the first driving mode, and the software of the DC-DC converter 600 may be in the second driving mode. For example, the hardware of the DC-DC converter 600 may be in the second driving mode, and the software of the DC-DC converter 600 may be in the first driving mode. In this case, in order to protect the DC-DC converter 600, the DC-DC converter 600 can be turned off.

[0123] In order to determine the inconsistency between the driving mode of the hardware of the DC-DC converter 600 and the driving mode of the software of the DC-DC converter 600 due to a setting error, the voltage of the common node of the third switching element S3 and the fourth switching element S4 (i.e., the second terminal of the third switching element S3) can be sensed.

[0124] For example, when the hardware of the DC-DC converter 600 is in the first driving mode and the software of the DC-DC converter 600 is in the second driving mode, in each single driving mode, based on the voltage of the common node of the third switching element S3 and the fourth switching element S4, it may not be switched in the hardware, but may be switched in the software. For example, when the hardware of the DC-DC converter 600 is in the second driving mode and the software of the DC-DC converter 600 is in the first driving mode, in each single driving mode, based on the voltage of the common node of the third switching element S3 and the fourth switching element S4, it may be switched in the hardware, and may not be switched in the software. Therefore, by sensing the voltage of the common node of the third switching element S3 and the fourth switching element S4, the inconsistency between the driving mode of the hardware of the DC-DC converter 600 and the driving mode of the software of the DC-DC converter 600 caused by the set error can be determined.

[0125] Fig.12 is a block diagram illustrating an electronic device. Fig.13 This is a diagram showing Fig.12 FIG. 1 is a diagram of an embodiment in which the electronic device is implemented as a smart phone device.

[0126] Reference Fig.12 and Fig.13 , the electronic device 1000 may include a processor 1010, a memory device 1020, a storage device 1030, an input / output ("I / O") device 1040, a power supply 1050, and a display device 1060. The display device 1060 may be Figure 1 The display device 10. In addition, the electronic device 1000 may further include a plurality of ports for communicating with a video card, a sound card, a memory card, a universal serial bus ("USB") device, and other electronic devices.

[0127] In an embodiment, Fig.13 As illustrated in , the electronic device 1000 may be implemented as a smart phone. However, the electronic device 1000 is not limited thereto. For example, the electronic device 1000 may be implemented as a cellular phone, a video phone, a smart tablet, a smart watch, a tablet PC, a car navigation system, a computer monitor, a laptop computer, and a head mounted display (“HMD”) device, etc.

[0128] The processor 1010 may perform various computing functions. The processor 1010 may be a microprocessor, a central processing unit ("CPU"), an application processor ("AP"), etc. The processor 1010 may be connected to other components via an address bus, a control bus, and a data bus, etc. In addition, the processor 1010 may be connected to an expansion bus such as a peripheral component interconnect ("PCI") bus.

[0129] The memory device 1020 may store data used for the operation of the electronic device 1000. For example, the memory device 1020 may include at least one nonvolatile memory device such as an erasable programmable read-only memory (“EPROM”) device, an electrically erasable programmable read-only memory (“EEPROM”) device, a flash memory device, a phase change random access memory (“PRAM”) device, a resistive random access memory (“RRAM”) device, a nano floating gate memory (“NFGM”) device, a polymer random access memory (“PoRAM”) device, a magnetic random access memory (“MRAM”) device, and a ferroelectric random access memory (“FRAM”) device, and / or at least one volatile memory device such as a dynamic random access memory (“DRAM”) device, a static random access memory (“SRAM”) device, and a mobile DRAM device.

[0130] The storage device 1030 may include a solid state drive ("SSD") device, a hard disk drive ("HDD") device, a CD-ROM device, and the like.

[0131] I / O device 1040 may include input devices such as a keyboard, a keypad, a mouse device, a touch pad, and a touch screen, or output devices such as a printer and a speaker, etc. In some embodiments, I / O device 1040 may include display device 1060 .

[0132] The power supply 1050 may provide power for the operation of the electronic device 1000 .

[0133] The display device 1060 may be connected to other components via a bus or other communication links.

[0134] The present invention can be applied to any display device and any electronic device including a touch panel. For example, the present invention can be applied to mobile phones, smart phones, digital televisions ("TV"), 3D TVs, personal computers ("PC") (e.g., tablet computers, laptop computers), home appliances, personal digital assistants ("PDAs"), portable multimedia players ("PMPs"), digital cameras, music players, portable game consoles, navigation devices, etc.

[0135] The foregoing is an illustration of the present invention and should not be construed as limiting it. Although some embodiments of the present invention have been described, it will be readily appreciated by those skilled in the art that many modifications are possible in the embodiments without substantially departing from the novel teachings and advantages of the present invention. Accordingly, all such modifications are intended to be included within the scope of the present invention as defined in the claims. In the claims, the device-plus-function clause is intended to cover structures described herein as performing the functions described, and not only structural equivalents, but also equivalent structures. Therefore, it should be understood that the foregoing is an illustration of the present invention and should not be construed as being limited to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the claims. The present invention is defined by the claims together with the equivalents of the claims that should be included therein.

Claims

1. A DC-DC converter, comprising: a main converter configured to operate to generate a panel power voltage based on an input voltage regardless of a panel current; as well as a slave converter configured to operate to generate the panel power voltage based on the input voltage together with the master converter when the panel current is greater than a reference current, Wherein, the master converter and the slave converter are connected to a first inductor.

2. The DC-DC converter according to claim 1, in, When the panel current is less than or equal to the reference current, the panel current flows to the main converter, and When the panel current is greater than the reference current, the panel current is split into the master converter and the slave converter.

3. The DC-DC converter according to claim 1, in, When the panel current is less than or equal to the reference current, the main converter is configured to generate a first inductor current flowing in the first inductor, and Wherein, when the panel current is greater than the reference current, the master converter and the slave converter are configured to generate the first inductor current together.

4. The DC-DC converter according to claim 1, wherein: When the panel current is greater than the reference current, the master converter and the slave converter are connected in parallel.

5. The DC-DC converter according to claim 4, wherein: When the master converter and the slave converter are connected in parallel, a combined resistance of the master converter and the slave converter is smaller than an internal resistance of each of the master converter and the slave converter.

6. The DC-DC converter according to claim 1, further comprising: a feedback voltage generator configured to divide the panel power voltage to generate a feedback voltage; as well as The error signal generator is configured to generate an error signal based on a voltage difference between the feedback voltage and a reference voltage.

7. The DC-DC converter according to claim 6, in, The main converter includes a first follower configured to alternately turn on a first switching element and a second switching element to generate at least a portion of a first inductor current flowing in the first inductor, and The slave converter includes a second follower configured to alternately turn on a third switching element and a fourth switching element to generate another part of the first inductor current.

8. The DC-DC converter according to claim 7, wherein: The main converter further comprises: a first switch controller configured to generate a first switch signal to control the first switch element, a second switch signal to control the second switch element, a third switch signal to control the third switch element and corresponding to the first switch signal, and a fourth switch signal to control the fourth switch element and corresponding to the second switch signal; and The first sensing current sensor is configured to sense a first sensing current flowing through the first switching element and a second sensing current flowing through the third switching element, and generate a first sensing voltage corresponding to a sum of the first sensing current and the second sensing current.

9. The DC-DC converter according to claim 8, wherein: The main converter further comprises: a first overcurrent protector configured to determine whether the sum of the first sensing current and the second sensing current is an overcurrent to generate a first enable signal for controlling the first switch controller; a first adder configured to add a ramp voltage to the first sensing voltage to generate a first sensing ramp voltage; and A first comparator is configured to compare the error signal and the first sensing ramp voltage to generate a first signal and output the first signal to the first switch controller.

10. The DC-DC converter according to claim 8, wherein: The first switching element includes a gate terminal receiving the first switching signal, a first terminal receiving the input voltage, and a second terminal connected to a first node. The second switching element includes a gate terminal receiving the second switching signal, a first terminal connected to the first node, and a second terminal connected to an output node, The third switching element includes a gate terminal receiving the third switching signal, a first terminal receiving the input voltage, and a second terminal connected to the first node. The fourth switching element includes a gate terminal receiving the fourth switching signal, a first terminal connected to the first node, and a second terminal connected to the output node, and The first inductor includes a first terminal connected to the first node and a second terminal connected to ground.

11. A DC-DC converter, comprising: a main converter configured to operate to generate a panel power voltage based on an input voltage regardless of a panel current; as well as a slave converter configured to operate to generate the panel power voltage based on the input voltage together with the master converter when the panel current is greater than a reference current, wherein, in a first driving mode, the master converter is connected to a first inductor, and the slave converter is connected to a second inductor, and Wherein, in a second driving mode, the master converter and the slave converter are connected to the first inductor.

12. The DC-DC converter according to claim 11, in, In the first driving mode and the second driving mode, when the panel current is less than or equal to the reference current, the panel current flows to the main converter, and Wherein, in the first driving mode and the second driving mode, when the panel current is greater than the reference current, the panel current is split into the main converter and the slave converter.

13. The DC-DC converter according to claim 11, wherein: In the first driving mode and the second driving mode, when the panel current is less than or equal to the reference current, the main converter is configured to generate a first inductor current flowing in the first inductor.

14. The DC-DC converter according to claim 13, in, In the first driving mode, when the panel current is greater than the reference current, the master converter is configured to generate the first inductor current, and the slave converter is configured to generate a second inductor current flowing in the second inductor, and Wherein, in the second driving mode, when the panel current is greater than the reference current, the master converter and the slave converter are configured to generate the first inductor current together.

15. The DC-DC converter according to claim 11, wherein: In the second driving mode, when the panel current is greater than the reference current, the master converter and the slave converter are connected in parallel.

16. The DC-DC converter according to claim 15, wherein: In the second driving mode, when the master converter and the slave converter are connected in parallel, a combined resistance of the master converter and the slave converter is smaller than an internal resistance of each of the master converter and the slave converter.

17. The DC-DC converter according to claim 11, further comprising: a feedback voltage generator configured to divide the panel power voltage to generate a feedback voltage; as well as The error signal generator is configured to generate an error signal based on a voltage difference between the feedback voltage and a reference voltage.

18. The DC-DC converter according to claim 17, in, The main converter includes a first follower configured to alternately turn on a first switching element and a second switching element in the first driving mode to generate a first inductor current flowing in the first inductor, and alternately turn on the first switching element and the second switching element in the second driving mode to generate at least a portion of the first inductor current, and The slave converter includes a second follower, which is configured to alternately turn on a third switching element and a fourth switching element in the first driving mode to generate a second inductor current flowing in the second inductor, and alternately turn on the third switching element and the fourth switching element in the second driving mode to generate the other part of the first inductor current.

19. The DC-DC converter according to claim 18, in, The main converter further includes: a first switch controller configured to generate a first switching signal for controlling the first switching element and a second switching signal for controlling the second switching element in the first driving mode, and to generate the first switching signal, the second switching signal, and a third switching signal for controlling the third switching element and corresponding to the first switching signal, and a fourth switching signal for controlling the fourth switching element and corresponding to the second switching signal in the second driving mode; and a first sensing current sensor configured to sense a first sensing current flowing through the first switching element and generate a first sensing voltage corresponding to the first sensing current in the first driving mode, and to sense the first sensing current and a second sensing current flowing through the third switching element and generate the first sensing voltage corresponding to the sum of the first sensing current and the second sensing current in the second driving mode, and Wherein, the slave converter further includes: a second switch controller, configured to generate the third switch signal and the fourth switch signal under the first driving mode; and a second sensing current sensor, configured to sense the second sensing current under the first driving mode and generate a second sensing voltage corresponding to the second sensing current.

20. The DC-DC converter according to claim 19, in, The main converter further includes: a first overcurrent protector configured to determine whether the first sensing current is an overcurrent in the first driving mode to generate a first enable signal to control the first switch controller, and to determine whether the sum of the first sensing current and the second sensing current is the overcurrent in the second driving mode to generate the first enable signal; a first adder configured to add a ramp voltage to the first sensing voltage to generate a first sensing ramp voltage; and a first comparator configured to compare the error signal and the first sensing ramp voltage to generate a first signal and output the first signal to the first switch controller, and Wherein, the slave converter further includes: a second overcurrent protector, configured to determine whether the second sensing current is the overcurrent in the first driving mode to generate a second enable signal for controlling the second switch controller; a second adder, configured to add the ramp voltage to the second sensing voltage to generate a second sensing ramp voltage; and a second comparator, configured to compare the error signal and the second sensing ramp voltage to generate a second signal and output the second signal to the second switch controller.

21. The DC-DC converter according to claim 18, wherein: A voltage of a common node of the third switching element and the fourth switching element is sensed so that a shut-down operation of the DC-DC converter is performed.

22. A display device, comprising: A display panel including pixels; and The DC-DC converter according to any one of claims 1 to 21, configured to output the panel power voltage to the display panel.

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