Power management device and display device comprising a power management device

Abstract

The present invention relates to a power management device and a display device including the same. The present invention relates to a technology for a power management device suitable for a display device in which driving voltages having different levels are supplied to driving devices having different sizes of loads at different times, and this allows all of the driving devices to stably receive voltages within a limited range even if the number of the driving devices increases according to enlargement of a display panel.

Description

TECHNICAL FIELD

[0001] The present application relates to a technology for supplying power to a device that drives a display apparatus. BACKGROUND

[0002] As the size of a display panel becomes larger, the number of devices for driving the display panel has gradually increased. A representative device for driving a display panel is a source driver for driving a data line connected to a pixel. The source driver can include a plurality of channels connected one-to-one to the data lines. However, since there is a limit to the number of channels that can be included in one source driver, a plurality of source drivers operate in a divided area in one display apparatus. In addition, as the size of a display apparatus becomes larger and thus the number of data lines increases, the number of source drivers included in one display apparatus also increases. The large size of a display panel not only increases the number of driving devices, but also increases the length of a wiring connected to the driving devices. The increase in the length of the wiring can cause voltage drop due to line impedance, and thus cause voltage imbalance between the driving devices. For example, a display apparatus can include a smaller number of power management devices than source drivers, and in such a structure, one power management device provides driving voltage to a plurality of source drivers. At this time, the plurality of source drivers connected to one power management device receive different voltage drop effects caused by line impedance depending on the relative distance from the power management device. For example, a source driver disposed close to the power management device receives a small voltage drop effect caused by line impedance, and a source driver disposed far from the power management device receives a large voltage drop effect caused by line impedance. Such a difference in voltage drop can cause imbalance in driving voltage input to the respective source drivers. As the size of a display panel becomes larger and thus the number of source drivers or the distance connected to one power management device increases, the problem of voltage imbalance between the source drivers becomes more serious.

[0003] The problem of voltage imbalance between driving devices becomes more serious when the driving devices perform a complex function. In a display apparatus, one driving device can perform a complex function. For example, a source readout integrated circuit (SRIC) can drive a data line connected to a pixel as one function, and can drive a sensor such as a touch sensor and read a sensed value as another function. The driving device having such a complex function can have a difference in current or power used to perform the function, thereby making the problem of voltage imbalance due to line impedance more serious.

[0004] On the other hand, voltage imbalance can cause a problem of being out of specification. Due to characteristics of elements or circuits, a range of input voltage that a driving device is able to receive can be limited to a predetermined range. When a voltage provided to the driving device corresponds to the predetermined range, it can be determined to be in specification, and otherwise, it can be determined to be out of specification. However, as described above, when voltage imbalance between driving devices becomes greater, a problem can occur in which one driving device becomes in specification while another driving device becomes out of specification. SUMMARY

[0005] In this background, one aspect of the present embodiment is to provide a technique for controlling a power management device so that all of voltages provided to a plurality of display driving devices are within a limited range.

[0006] According to an aspect of the present disclosure, a display device includes at least one driving device configured to transmit a data voltage to a pixel provided on a panel in a display time interval and to transmit a touch driving signal to a sensor provided in the panel in a touch sensing time interval, a power management device connected with the at least one driving device through a power line and configured to supply a first voltage having a first level to the power line in the display time interval and to supply a second voltage having a second level higher than the first level to the power line in the touch sensing time interval, and a timing control device configured to supply a timing control signal indicating the display time interval and the touch sensing time interval to the at least one driving device or to the power management device. The at least one driving device can supply a common voltage to the sensor in the display time interval and transmit the touch driving signal to the sensor in the touch sensing time interval. Here, an amount of current consumed for generating the touch driving signal can be greater than an amount of current consumed for generating the data voltage.

[0007] According to another aspect of the present disclosure, a power management device is provided, which is connected with a display driving device through a power line. The power management device includes a first voltage generation module configured to generate a first voltage having a first level, a second voltage generation module configured to generate a second voltage having a second level higher than the first level, and an output control circuit configured to receive a timing control signal indicating a display time interval and a touch sensing time interval, to output the first voltage to the power line in the display time interval and to output the second voltage to the power line in the touch sensing time interval through a switching circuit.

[0008] The driving device can receive the timing control signal from a timing control device configured to transmit image data and distinguish a driving time of a pixel and a driving time of a sensor, and the output control circuit can receive the timing control signal from the timing control device and identify the display time interval and the touch sensing time interval.

[0009] According to another aspect of the present disclosure, a power management device is provided, which is connected to a display driving device through a power line. The power management device includes a gate control circuit configured to turn on or off a power switch configured to adjust a voltage across an inductor for power conversion, a feedback loop circuit configured to generate a comparison signal by comparing a sensed voltage for output with a reference, and transmit a control signal for the gate control circuit according to the comparison signal, and a control circuit configured to control the reference to correspond to a first voltage in a display time interval and control the reference to correspond to a second voltage higher than the first voltage in a touch sensing time interval, or control the sensed voltage to correspond to the first voltage in the display time interval and control the sensed voltage to correspond to the second voltage in the touch sensing time interval.

[0010] The control circuit can include a switching circuit configured to select and output one of a plurality of references, and can select one of the plurality of references and output the selected reference according to a timing control signal. The display driving device can supply a predetermined direct current voltage, i.e., a predetermined DC voltage, to a sensor in the display time interval, and supply a touch driving signal to the sensor in the touch sensing time interval.

[0011] The display driving device has a level of output current in the display time interval lower than a level of output current in the touch sensing time interval.

[0012] According to another aspect of the present disclosure, a power management device is provided, which is connected to a display driving device through a power line. The power management device includes a gate control circuit configured to turn on or off a power switch configured to adjust a voltage across an inductor for power conversion, a feedback loop circuit configured to generate a comparison signal by comparing a sensed voltage for output with a reference, and transmit a control signal for the gate control circuit according to the comparison signal, and a control circuit configured to control the reference to correspond to a first voltage in a display time interval and control the reference to correspond to a second voltage higher than the first voltage in a touch sensing time interval, or control the sensed voltage to correspond to the first voltage in the display time interval and control the sensed voltage to correspond to the second voltage in the touch sensing time interval.

[0013] According to the above-described embodiment, although the size of the display panel is large, the difference in the device voltage provided to the display driving device can be minimized. Further, according to the embodiment, although the driving device performs a plurality of functions and there is a difference between the functions in current or power usage, all of the driving voltages input from the power management device can be within a limited range. Further, according to the embodiment, although the size of the display driving device is large, all of the voltages provided to the plurality of display driving devices can be within a limited range. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a block diagram illustrating a display device according to an embodiment;

[0015] Figure 2 illustrates a structure of a pixel and a sensor in an in-cell panel;

[0016] Figure 3 illustrates main voltage and current waveforms according to the related art;

[0017] Figure 4 illustrates main voltage and current waveforms according to the embodiment;

[0018] Figure 5 is a block diagram illustrating a first example of a power management device according to an embodiment;

[0019] Figure 6 is a block diagram illustrating a second example of a power management device according to an embodiment;

[0020] Figure 7 is a block diagram illustrating a third example of a power management device according to an embodiment; and

[0021] Figure 8 is a block diagram illustrating a fourth example of a power management device according to an embodiment. DETAILED DESCRIPTION

[0022] Figure 1 is a block diagram illustrating a display device according to an embodiment.

[0023] REFERENCE Figure 1 , the display device 100 can include a panel 110, a power management device 120, driving devices 130a to 130m, a wiring device 140, and a timing control device 150, etc.

[0024] A plurality of pixels P and a plurality of sensors SE can be arranged on the panel 110.

[0025] Pixel P is a unit element used to display an image, and its brightness can be controlled based on the grayscale value included in the pixel data. Pixel P is connected to driving devices 130a to 130m via data lines DL, and driving devices 130a to 130m can provide a data voltage VD to the data lines DL to control the brightness of pixel P. Driving devices 130a to 130m can receive image data RGB from a timing control device 150, etc., convert the pixel data included in the image data RGB into a data voltage VD corresponding to an analog voltage, and provide this data voltage VD to each data line DL.

[0026] The sensor SE is a unit element used to detect the touch or proximity of an external object and can be driven by a touch drive signal TXS. The sensor SE can be connected to the driving devices 130a to 130m via sensor lines SL, and the driving devices 130a to 130m can provide the touch drive signal TXS and read the response signal generated in the sensor SE to generate a sensing value. Furthermore, the driving devices 130a to 130m can convert this sensing value into sensing data and send it to, for example, a touch master control unit (TMCU). The size of a pixel P can be smaller than the size of the sensor SE. Therefore, multiple pixels P can overlap in one sensor SE. In a frame, the data voltage VD can be in the form of a DC voltage. For example, when pixel data is determined to be a specific value, the data voltage VD can maintain a specific DC voltage based on that pixel data. On the other hand, in a frame, the touch drive signal TXS can be in the form of an AC voltage. The touch drive signal TXS can be in the form of an AC voltage such as a square wave or a sine wave, and the driving devices 130a to 130m can provide the touch drive signal TXS to the sensor SE and sense the magnitude of the response signal based on the change in the capacitance of the sensor SE.

[0027] On the other hand, the capacitance generated by the data line DL and pixel P is finite, and DC voltage is supplied to the data line DL, thus allowing for a relatively small current or power to be used when driving pixel P. Conversely, since the capacitance generated by the sensor SE is relatively large, and AC voltage is supplied to the sensor line SL, a relatively large current or power can be used when driving the sensor SE. When the driving devices 130a to 130m perform both functions of driving pixel P and driving sensor SE, as described above, the current or power used for these functions can differ from each other. Such a difference can cause a difference in the timing of voltage supply from the power management device 120.

[0028] Power management device 120 can provide drive voltage to multiple drive devices 130a to 130m via power lines PL. A portion of the power lines PL can be arranged on wiring device 140. Wiring device 140 may include a flexible printed circuit board (FPCB), through which the power lines PL can be arranged. Connectors with physical structures can be arranged on the power lines PL. The power lines PL may have line impedance, and the line impedance may increase due to the characteristics of the FPCB and the connectors. The drive voltage supplied to the multiple drive devices 130a to 130m may drop due to line impedance and be input to the drive devices 130a to 130m. Drive devices with short wiring between the drive devices and power management device 120 may have a small voltage drop (line voltage) caused by line impedance, while drive devices with long wiring between the drive devices and power management device 120 may have a large voltage drop (line voltage) caused by line impedance. For example, the magnitude of the line voltage generated on the wiring between the first drive unit 130a, which is arranged closest to the power management device 120, and the power management device 120 can be smaller than the magnitude of the line voltage generated on the wiring between the Nth drive unit 130n, which is arranged furthest from the power management device 120, and the power management device 120.

[0029] The power management device 120 can generate a voltage that minimizes the time difference and position difference of the voltage supplied to the drive devices 130a to 130m, and provides the generated voltage.

[0030] The power management device 120 can provide a first voltage to the power line PL during a first time interval with a low load, from the drive device 130a to 130m, and a second voltage to the power line PL during a second time interval with a relatively high load. For example, the power management device 120 can provide a first voltage with a first level to the power line PL during the display time interval when the drive device 130a to 130m provides a data voltage VD to the pixel, and a second voltage with a second level to the power line PL during the touch sensing time interval when the drive device 130a to 130m provides a touch drive signal TXS to the sensor SE. The second level can be higher than the first level.

[0031] The timing control device 150 can generate a timing control signal TCS for separating a first time interval and a second time interval. The timing control device 150 can generate the timing control signal TCS, send the timing control signal TCS to the drive devices 130a to 130m, and send the timing control signal TCS to the power management device 120.

[0032] In the following description, for ease of description, the display time interval and touch sensing time interval will be described as examples of a first time interval and a second time interval. However, this embodiment is not limited to this, and it can be understood that the first time interval is a time interval with relatively low load, and the second time interval is a time interval with relatively high load. Alternatively, it can be understood that the first time interval is a time interval in which DC voltage is provided as load, and the second time interval can be a time interval in which AC voltage is provided as load.

[0033] The separation of time intervals and the driving of different loads by the drive units 130a to 130m are due to the miniaturization or integration of the drive units. When one of the drive units 130a to 130m performs multiple functions, the overall size of the drive unit may be reduced, and the power consumption may also be reduced. When some components within the panel 110 perform two or more functions, the gain due to miniaturization, thinning, and low power consumption is further increased, and embedded panels are a representative example.

[0034] Figure 2 The structure of the pixels and sensors in the embedded panel is shown.

[0035] refer to Figure 2 In this configuration, a pixel electrode (PE), a liquid crystal LC (LC), and a transistor TFT (TFT) can be arranged on the pixel P. The drain of the transistor TFT can be connected to the data line DL, its source can be connected to the pixel electrode PE, and its gate can be connected to the gate line GL. When the scan signal SCAN provided to the gate line GL goes high, the transistor TFT can be turned on, and the data voltage VD generated on the data line DL can be provided to the pixel electrode PE. When the scan signal SCAN goes low, the transistor TFT can be turned off, and the data voltage VD generated on the pixel electrode PE can be maintained for one frame. The liquid crystal LC can control the amount of light supplied from the backlight to control the brightness of the pixel P while the angle changes according to the voltage generated on the pixel electrode PE. In this structure, the data voltage VD is used only during the time when the voltage is charged to the pixel electrode PE, and therefore the power used may be small. On the other hand, in an in-cell panel, the pixel electrode PE controls the liquid crystal LC based on the voltage difference with the sensor SE, and in this case, the sensor SE is used as a common electrode for providing a common voltage. The time interval for providing data voltage VD to pixel P can be the display time interval, and a common voltage corresponding to DC voltage can be provided to sensor SE during the display time interval.

[0036] When the display time interval ends, sensor SE is used as the electrode for detecting touch, and this time can be the touch sensing time interval. During the touch sensing time interval, a touch drive signal TXS is provided to the sensor line SL connected to sensor SE, and at this time, the touch drive signal TXS can have a square wave waveform as shown in the figure. Since sensor SE has a relatively large area and a large capacitance generated between sensor SE and adjacent electrodes, a large amount of power is used to generate the touch drive signal TXS in the form of AC voltage.

[0037] In this structure, compared with the prior art, the waveforms of the voltages input to each drive device at various times and locations are described.

[0038] Figure 3 The main voltage and current waveforms according to the prior art are shown.

[0039] refer to Figure 3 The timing control signal TCS can have a high voltage during the display time interval D and a low voltage during the touch sensing time interval T, thus separating the time interval into the display time interval D and the touch sensing time interval T.

[0040] The load current Lo can be a first current Lo1 during the display time interval D, and a second current Lo2 during the touch sensing time interval T. The level of the second current Lo2 can be higher than the level of the first current Lo1. The output voltage Vo of the power management device can be maintained at a single level.

[0041] The first driving voltage Vai, supplied via the power line to the first driving device arranged closest to the power management device, can have a voltage level of Vai1 during the display time interval D and a voltage level of Vai2 during the touch sensing time interval T. The Nth driving voltage Vni, supplied via the power line to the Nth driving device arranged furthest from the power management device, can have a voltage level of Vni1 during the display time interval D and a voltage level of Vni2 during the touch sensing time interval T.

[0042] The voltage input to each drive unit via the power line can be limited to a predetermined range. When the upper limit of this predetermined range is the upper voltage level Vlu and the lower limit is the lower voltage level Vld, since both Vai1 and Vai2 are lower than the upper voltage level Vlu and higher than the lower voltage level Vld, the first drive voltage Vai can be within the predetermined range.

[0043] On the other hand, for the Nth driving voltage Vni, Vni1 can be within a predetermined range, but Vni2 can be lower than the lower voltage level Vld and may deviate from the predetermined range.

[0044] To address the non-compliance issues in the prior art, the power management device according to the embodiment can control the output voltage level in different ways at different times.

[0045] Figure 4 The main voltage and current waveforms according to this embodiment are shown.

[0046] refer to Figure 4 The timing control signal TCS can have a high voltage during the display time interval D and a low voltage during the touch sensing time interval T, thus separating the time interval into the display time interval D and the touch sensing time interval T.

[0047] The load current Lo can be a first current Lo1 during the display time interval D, and the load current Lo can be a second current Lo2 during the touch sensing time interval T. The level of the second current Lo2 can be higher than that of the first current Lo1.

[0048] The power management device can provide a first voltage Vol with a first level to the power line during the display time interval D, and a second voltage Vo2 with a second level to the power line during the touch sensing time interval T. The first level can be lower than the second level.

[0049] The voltage input to each drive unit via the power line can be limited to a predetermined range. When the upper limit of this predetermined range is the upper voltage level Vlu and the lower limit is the lower voltage level Vld, since both Vai1 and Vai2 are lower than the upper voltage level Vlu and higher than the lower voltage level Vld, the first drive voltage Vai can be within the predetermined range.

[0050] Similarly, in the Nth driving voltage Vni, both the voltage Vni1 generated in the display time interval and the voltage Vni2 generated in the touch sensing time interval are lower than the upper voltage level Vlu and higher than the lower voltage level Vld, and therefore can be within a predetermined range.

[0051] The power management device can generate an output voltage Vo such that the difference in drive voltage between different times is minimized for the drive devices positioned furthest from the power management device. For example, if the line voltage during the display time interval is a first line voltage and the line voltage during the touch sensing time interval is a second line voltage for the Nth drive device positioned furthest from the power management device, the power management device can control the difference in output voltage Vo between different times, Vo2-Vo1, to be substantially the same as the difference between the second line voltage and the first line voltage. With this control, the drive voltage Vni of the Nth drive device may have very little difference between different times, and the designer can more easily check whether the drive voltage Vni has become compliant. By comparing the difference between the first voltage and the second voltage from the power line input to the multiple drive devices, it can be noted that the difference between the first voltage Vai1 and the second voltage Vai2 of the first drive device positioned closest to the power management device is greater than the difference between the first voltage Vni1 and the second voltage Vni2 of the Nth drive device positioned furthest from the power management device. The power management device can control the levels of the first voltage and the second voltage, such that the difference between the first voltage and the second voltage input to each drive device becomes smaller as the distance from the power management device increases.

[0052] The power management device according to the embodiments can be implemented in various forms. The power management device can be implemented as a single integrated circuit or as multiple integrated circuits. Figures 5 to 8 The document describes an implementation example of a power management device.

[0053] Figure 5 This is a block diagram illustrating a first example of a power management device according to an embodiment.

[0054] refer to Figure 5 The power management device 120a may include a first voltage generation module 510, a second voltage generation module 520, and an output control circuit 530, etc.

[0055] The first voltage generation module 510 can generate a first voltage Vo1 having a first level. The second voltage generation module 520 can generate a second voltage having a second level. The first level may be lower than the second level. The first voltage generation module 510 and the second voltage generation module 520 can be configured with separate converters, such as buck converters. The buck converter may include a power terminal having an inductor, an output capacitor, a power switch, and a power diode, and a gate control circuit for controlling the power switch of the power terminal. The first voltage generation module 510 and the second voltage generation module 520 may include the gate control circuit as part of their configuration, and may also include the power switch according to an embodiment. The remaining components may be arranged in an external circuit.

[0056] The output control circuit 530 can selectively output the first voltage Vo1 and the second voltage Vo2 to the power supply line PL.

[0057] The output control circuit 530 may include a first switch SW1 for controlling the output of a first voltage Vo1 to the power line PL and a second switch SW2 for controlling the output of a second voltage Vo2 to the power line PL. When the first voltage generation module 510 and the second voltage generation module 520 include output capacitors, the first switch SW1 may be arranged between the first voltage generation module 510 and the power line PL, and the second switch SW2 may be arranged between the second voltage generation module 520 and the power line PL.

[0058] The output control circuit 530 may also include a switch control circuit 532. The switch control circuit 532 can control the first switch SW1 and the second switch SW2 to be turned on / off according to the timing control signal TCS.

[0059] The first voltage generation module 510 and the second voltage generation module 520 can be implemented as integrated circuits. The output control circuit 530 can be implemented as a discrete circuit without being included in an integrated circuit.

[0060] Figure 6 This is a block diagram illustrating a second example of a power management device according to an embodiment.

[0061] refer to Figure 6 The power management device 120b may include a first integrated circuit 610 and a second integrated circuit 620, etc.

[0062] The first integrated circuit 610 may include a first voltage generation module 612, a first switch SW1, and a first switch control circuit 614.

[0063] The first voltage generation module 612 can generate a first voltage Vo1 having a first level. The first voltage generation module 612 can be configured with a converter, such as a buck converter. The buck converter may include a power terminal having an inductor, an output capacitor, a power switch, and a power diode, and a gate control circuit for controlling the power switch of the power terminal. The first voltage generation module 612 may include the gate control circuit as part of its configuration, and may also include the power switch according to an embodiment. The remaining components may be arranged in an external circuit.

[0064] The first switch SW1 can control the output of the first voltage Vo1 to the power line PL. The first switch control circuit 614 can control the first switch SW1 to be turned on / off according to the timing control signal TCS, and control whether the first voltage Vo1 can be output to the power line PL.

[0065] The second integrated circuit 620 may include a second voltage generation module 622, a second switch SW2, and a second switch control circuit 624.

[0066] The second voltage generation module 622 can generate a second voltage Vo2 having a second level. The second voltage generation module 622 can be configured with a converter, such as a buck converter. The buck converter may include a power terminal having an inductor, an output capacitor, a power switch, and a power diode, and a gate control circuit for controlling the power switch of the power terminal. The second voltage generation module 622 may include the gate control circuit as part of its configuration, and may also include the power switch according to an embodiment. The remaining components may be arranged in an external circuit.

[0067] The second switch SW2 can control the output of the second voltage Vo2 to the power line PL. The second switch control circuit 624 can control the on / off state of the second switch SW2 according to the timing control signal TCS, and control whether or not the second voltage Vo2 can be output to the power line PL.

[0068] Figure 7 This is a block diagram illustrating a third example of a power management device according to an embodiment.

[0069] refer to Figure 7 The power management device 120c may include a gate control circuit 710, a feedback loop circuit 720, and a reference control circuit 730, etc.

[0070] The gate control circuit 710 can turn the gate of the power switch PS on or off to control the voltage across the inductor L used for power conversion. The power supply terminal 70 may include the power switch PS, the power diode PD, the inductor L, and the output capacitor Co, and the gate control circuit 710 can control the on / off state of the power switch PS. When the power supply terminal 70 is configured as a buck converter, if the power switch PS is on, a power input voltage and a power output voltage are generated across the inductor L; and if the power switch PS is off, a ground voltage and a power output voltage are generated across the inductor L. The gate control circuit 710 can control the voltage across the inductor L, and therefore control the output voltage of the power supply terminal 70.

[0071] The feedback loop circuit 720 can sense the output voltage of the power supply terminal. When this voltage is sensed, the feedback loop circuit 720 can, based on, such as Figure 7The resistors shown heat Ro1 and Ro2 to sense the step-down voltage. The feedback loop circuit 720 compares the sensed voltage with a reference using a comparator CMP and generates a comparison signal. Furthermore, the feedback loop circuit 720 can generate a control signal based on this comparison signal using a loop control circuit 722. The loop control circuit 722 may include a proportional-integral-derivative (PID) circuit and a triangular wave circuit, etc.

[0072] A control signal corresponding to the output of the feedback loop circuit 720 can be transmitted to the gate control circuit 710, which can then control the gate of the power switch PS according to the control signal. The reference control circuit 730 can generate multiple references Vr1 and Vr2, and selectively output one of these references to the feedback loop circuit 720.

[0073] The reference control circuit 730 can control these references to correspond to a first voltage in the display time interval, and control these references to correspond to a second voltage higher than the first voltage in the touch sensing time interval.

[0074] The reference control circuit 730 may include a reference generation circuit 732 for generating multiple references Vr1 and Vr2, a switch positioning circuit MUX for selecting and outputting one of the multiple references Vr1 and Vr2, and a switch control circuit 734 for controlling the switch circuit MUX.

[0075] The switch control circuit 734 can receive a timing control signal TCS, and according to the timing control signal TCS, output a first reference Vr1 through the switch circuit MUX during the display time interval, and output a second reference Vr2 through the switch MUX during the touch sensing time interval.

[0076] The switch control circuit 734 can receive control values ​​for references via I2C communication. The switch control circuit 734 can receive control values ​​via I2C communication and, based on these control values, allow the output of a first reference Vr1 or a second reference Vr2.

[0077] Figure 8 This is a block diagram illustrating a fourth example of a power management device according to an embodiment.

[0078] refer to Figure 8 The power management device 120d may include a gate control circuit 710, a feedback loop circuit 720, and a sensing voltage control circuit 830, etc.

[0079] A control signal corresponding to the output of the feedback loop circuit 720 can be transmitted to the gate control circuit 710, and the gate control circuit 710 can control the gate of the power switch PS according to the control signal. On the other hand, in the feedback loop circuit 720, the reference Vr can be input to the input terminal of the comparator CMP. The other input terminal of the comparator CMP can be connected to the output of the sensing voltage control circuit 830.

[0080] The sensing voltage control circuit 830 can sense the output of the power supply terminal 70, step down or boost the output at a predetermined rate, and input the output to the comparator CMP. The sensing voltage control circuit 830 may include programmable circuitry (e.g., programmable resistors, programmable capacitors, and programmable digital-to-analog converters (DACs), etc.), and this programmable circuitry can be modified according to a timing control signal TCS or a communication signal I2C. The sensing voltage control circuit 830 can adjust the sensing rate of the output according to the modified programmable circuitry and transmit this sensing rate to the feedback loop circuit 720.

[0081] The sensing voltage control circuit 830 can use programmable circuitry to adjust the sensing rate of the output and change the state of the programmable circuitry in different ways during the display time interval and the touch sensing time interval. For example, the sensing voltage control circuit 830 can generate a sensing voltage by stepping down the output. In this case, the sensing voltage control circuit 830 can change the state of the programmable circuitry to adjust the step-down rate. The sensing voltage control circuit 830 can generate a sensing voltage by further stepping down the output during the touch sensing time interval than during the display time interval. Therefore, the output voltage can be controlled to be higher during the touch sensing time interval compared to the display time interval.

[0082] The sensing voltage control circuit 830 can control the sensing voltage to correspond to a first voltage in the display time interval, and control the sensing voltage to correspond to a second voltage higher than the first voltage in the touch sensing time interval.

[0083] As described above, in this embodiment, drive voltages of different amplitudes at different times are provided to drive devices with different loads at different times. Therefore, even if the number of drive devices increases due to their large size, all drive devices can stably receive voltages within a limited range. According to this embodiment, although the display panel is enlarged, the voltage difference supplied to the display drive devices between devices can be minimized. Furthermore, according to this embodiment, although the drive devices perform multiple functions and there are differences in their functions in terms of current or power usage, all drive voltages input from the power management device can be within a limited range. Additionally, according to this embodiment, although the display panel is enlarged, all voltages supplied to multiple display drive devices can be within a limited range.

[0084] Cross-references to related applications

[0085] This application claims priority to Korean Patent Application No. 10-2020-0106916, filed on August 25, 2020, the entire contents of which are incorporated herein by reference.

Claims

1. A display device, comprising: Multiple driving devices are configured to send data voltages to pixels disposed on the panel during a display time interval and to send touch driving signals to sensors disposed on the panel during a touch sensing time interval. A power management device is connected to at least one of the plurality of driving devices via a power line and is configured to provide a first voltage having a first level to the power line during the display time interval and to provide a second voltage having a second level higher than the first level to the power line during the touch sensing time interval. as well as A timing control device configured to provide a timing control signal indicating the display time interval and the touch sensing time interval to at least one of the plurality of driving devices or to the power management device. The plurality of drive devices are arranged at different locations along the power line, and the power management device is configured to control the levels of the first voltage and the second voltage such that the difference between the first voltage and the second voltage supplied through the power line to the drive device arranged furthest from the power management device is less than the difference between the first voltage and the second voltage supplied through the power line to the drive device arranged closest to the power management device.

2. The display device according to claim 1, wherein, The power lines are arranged via a flexible printed circuit board (FPCB) or include connectors with a physical structure.

3. The display device according to claim 1, wherein, The power management device includes a plurality of voltage generation modules configured to generate the first voltage and the second voltage, and the plurality of voltage generation modules are selectively connected to the power line via a switching circuit.

4. The display device according to claim 1, wherein, At least one of the plurality of driving devices provides a common voltage to the sensor during the display time interval and sends the touch driving signal to the sensor during the touch sensing time interval.

5. The display device according to claim 4, wherein, The current consumed to generate the touch drive signal is greater than the current consumed to generate the data voltage.

6. A power management device connected to a display driver via a power cord, the power management device comprising: A first voltage generation module is configured to generate a first voltage having a first level. The second voltage generation module is configured to generate a second voltage having a second level higher than the first level. as well as An output control circuit is configured to receive a timing control signal indicating a display time interval and a touch sensing time interval, and to output a first voltage to the power line during the display time interval and a second voltage to the power line during the touch sensing time interval via a switching circuit. The display driving device is connected to the power line at different locations, and the difference between the first voltage and the second voltage supplied to the driving device arranged furthest from the power management device among the plurality of driving devices through the power line is less than the difference between the first voltage and the second voltage supplied to the driving device arranged closest to the power management device among the plurality of driving devices through the power line.

7. The power management device according to claim 6, wherein, The driving device receives the timing control signal from the timing control device configured to send image data and distinguishes the driving time of the pixels and the driving time of the sensor, and the output control circuit receives the timing control signal from the timing control device and identifies the display time interval and the touch sensing time interval.

8. The power management device according to claim 6, wherein, The first voltage generation module is embedded in the first integrated circuit, and the second voltage generation module is embedded in the second integrated circuit. The switching circuit is embedded in the first integrated circuit and the second integrated circuit in the form of an output switch.

9. A power management device connected to a display driver via a power cord, the power management device comprising: A gate control circuit configured to turn on or off a power switch configured to adjust the voltage across an inductor used for power conversion; A feedback loop circuit is configured to generate a comparison signal by comparing a sensed voltage for output with a reference, and to send a control signal for the gate control circuit based on the comparison signal. as well as A control circuit is configured to control the reference to correspond to a first voltage in a display time interval and to control the reference to correspond to a second voltage higher than the first voltage in a touch sensing time interval, or to control the sensing voltage to correspond to the first voltage in the display time interval and to control the sensing voltage to correspond to the second voltage in the touch sensing time interval.

10. The power management device according to claim 9, wherein, The control circuit includes a switching circuit configured to select and output one of a plurality of references, and to select one of the plurality of references and output the selected reference according to a timing control signal.

11. The power management device according to claim 9, wherein, One of the display driving devices provides a data voltage to the pixel during the display time interval and provides a touch driving signal to the sensor during the touch sensing time interval.

12. The power management device according to claim 9, wherein, One of the display driving devices provides a predetermined DC voltage to the sensor during the display time interval, and provides a touch driving signal to the sensor during the touch sensing time interval.

13. The power management device according to claim 9, wherein, The level of the output current of one of the display driving devices during the display time interval is lower than the level of the output current during the touch sensing time interval.

14. The power management device according to claim 9, wherein, The control circuit generates the sensing voltage by stepping down the output, and further generates the sensing voltage by stepping down the output during the touch sensing time interval compared to the display time interval.

15. The power management device according to claim 9, wherein, The control circuit uses a programmable circuit to adjust the sensing rate of the output, wherein the state of the programmable circuit changes in different ways during the display time interval and the touch sensing time interval.

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