Power supply chip and display device

Abstract

The application discloses a power supply chip and a display device, and belongs to the technical field of display. The display device comprises a GOA circuit, and the power supply chip is configured to convert a power supply voltage into an initialization signal when power is turned on, and transmit the initialization signal to the GOA circuit, so that the GOA circuit discharges a pull-up node according to the initialization signal, and stops outputting the initialization signal after a voltage value of a driving signal of the GOA circuit reaches an effective value. By adopting the power supply chip to generate the initialization signal, the generation of the initialization signal is separated from a time sequence controller and a level converter, so that the pull-up node is discharged before a voltage other than the power supply voltage is started when the display device starts to be powered on, and the pull-up node PU is ensured to have no electric charge when the display device works.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of display, and particularly relates to a power supply chip and a display device. BACKGROUND

[0002] In TFT-LCD (Thin Film Transistor-Liquid Crystal Display) products, the PU (pull-up node) in the GOA unit needs to be discharged when starting power-on. However, the current pull-up node PU charge cannot be completely released. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a power supply chip and a display device, which discharges the pull-up node when the display device starts power-on, and ensures that the pull-up node PU has no charge when the display device works.

[0004] In a first aspect, the present application provides a power supply chip of a display device, the display device comprising a GOA circuit, the power supply chip being configured to convert a power supply voltage into an initialization signal when power-on, and transmit the initialization signal to the GOA circuit, so that the GOA circuit discharges a pull-up node according to the initialization signal, and stops outputting the initialization signal after the voltage value of a driving signal of the GOA circuit reaches an effective value.

[0005] According to an embodiment of the present application, the power supply chip comprises a frequency control circuit, a switch circuit and a charge pump connected in sequence;

[0006] The switch circuit is configured to be controlled to be turned on or turned off;

[0007] The charge pump is configured to convert the input power supply voltage into the initialization signal under the control of the frequency control circuit.

[0008] According to an embodiment of the present application, the switch circuit is configured to input a driving signal, and is turned on or turned off according to the voltage of the driving signal.

[0009] According to an embodiment of the present application, the switch circuit comprises a MOS tube, the source of the MOS tube is electrically connected with the frequency control circuit, the drain of the MOS tube is electrically connected with the charge pump, and the gate of the MOS tube is configured to input the driving signal.

[0010] According to an embodiment of the present application, the frequency control circuit is further electrically connected with the gate of the MOS tube, and is configured to control the MOS tube to be turned off according to the voltage of the driving signal.

[0011] According to one embodiment of the present application, the power supply chip is configured to convert the power supply voltage into a reference voltage, the reference voltage being used to drive the timing controller or the data driving circuit.

[0012] According to one embodiment of the present application, the power supply chip is configured to convert the power supply voltage into a driving signal.

[0013] In a second aspect, the present application provides a display device, comprising the power supply chip according to the foregoing.

[0014] According to one embodiment of the present application, the display device comprises a display substrate, the display substrate being provided with a GOA circuit, discharge control ends of the GOA circuit being electrically connected with cathodes of the first diode and the second diode respectively, an anode of the first diode being electrically connected with an initialization signal output end of the power supply chip, and an anode of the second diode being electrically connected with an initialization signal output end of the level shifter.

[0015] According to one embodiment of the present application, the level shifter outputs a discharge signal when the driving signal voltage value is pulled up to the maximum value, so that the GOA circuit discharges the pull-up node according to the discharge signal.

[0016] According to the power supply chip and the display device of the present application, the initialization signal is generated by using the power supply chip, and the generation of the initialization signal is separated from the timing controller and the level shifter, so that the pull-up node is discharged before the voltage other than the power supply voltage is started when the display device starts to be powered on, and the pull-up node PU is ensured to have no charge when the display device works.

[0017] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings, wherein:

[0019] Figure 1 is a structural schematic diagram of a display device provided by an embodiment of the present application;

[0020] Figure 2 is one of structural schematic diagrams of a GOA circuit provided by an embodiment of the present application;

[0021] Figure 3 is another one of structural schematic diagrams of a GOA circuit provided by an embodiment of the present application;

[0022] Figure 4 is a structural schematic diagram of a power supply chip provided by an embodiment of the present application;

[0023] Figure 5is a circuit structure diagram of a discharge control end of a GOA circuit provided by an embodiment of the present application;

[0024] Figure 6 is a signal timing diagram provided by an embodiment of the present application.

[0025] Reference signs:

[0026] Power supply chip 100, frequency control circuit 110, switch circuit 120, charge pump 130, GOA circuit 200, MOS tube Q1, first to second diodes D1-D2. DETAILED DESCRIPTION

[0027] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0028] In the following description, “circuit” refers to a conductive loop composed of at least one element or sub-circuit through electrical or electromagnetic connection. When an element or circuit is said to be “coupled to” or “connected to” another element or said element / circuit is “coupled between” or “connected between” two nodes, it can be directly coupled or connected to another element or there can be intermediate elements, and the connection between elements can be physical, logical, or a combination thereof. On the contrary, when an element is said to be “directly coupled to” or “directly connected to” another element, it means that there is no intermediate element between the two.

[0029] In the description, the terms “first”, “second”, etc. are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the numerical descriptors used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by “first”, “second”, etc. are usually a class, and are not limited to the number of objects, for example, the first object can be one or more. In addition, “and / or” in the specification and claims indicates at least one of the connected objects, and the character “ / ” generally indicates that the associated objects before and after are in an “or” relationship.

[0030] In addition, reference to a term "one embodiment", "some embodiments", "certain embodiments" or "some examples", etc., means that a particular feature, structure, material, or characteristic being described in connection with this embodiment or example is included in at least one embodiment or example of the application. The appearances of the phrases in various places in the specification are not necessarily all referring to the same embodiment or example. Furthermore, the described particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0031] With reference to Figure 1 The embodiment of the application provides a power supply chip 100 of a display device, and the display device comprises a GOA circuit 200. In the embodiment, the power supply chip 100 is configured to convert a power supply voltage VDD into an initialization signal VGH1 when power is turned on, and transmit the initialization signal VGH1 to the GOA circuit 200, so that the GOA circuit 200 discharges a pull-up node PU according to the initialization signal VGH1, and stops outputting the initialization signal VGH1 after a voltage value of a driving signal VGH of the GOA circuit 200 reaches a valid value.

[0032] In the embodiment, the display device is a TFTLCD (Thin Film Transistor Liquid Crystal Display) product in a GOA (Gate Driver on Array) mode. In the process of switching on and off of the display device, the pull-up node PU in the GOA circuit 200 needs to be discharged, so as to avoid that pixels in a display area are mistakenly turned on.

[0033] In the related art, an initialization signal of the GOA circuit 200 is provided with a working voltage by a power management integrated circuit PMIC to a timing controller, and the timing controller controls a level shifter to output the initialization signal. Therefore, when the initialization signal is output, the timing controller and the level shifter have started working, and at this time, the GOA circuit 200 starts discharging, and the discharging is easy to be incomplete.

[0034] In the embodiment, the power supply chip 100 can be the PMIC, that is, the PMIC directly generates the initialization signal VGH1. Alternatively, the power supply chip 100 can be an external chip, which is separately powered by using the power supply voltage, so that when the power supply voltage VDD starts to be input, the initialization signal VGH1 is directly generated, and the GOA circuit 200 starts discharging.

[0035] The power supply chip 100 can also access the driving signal VGH of the GOA circuit 200 to control the output of the initialization signal VGH1 according to the voltage of the driving signal VGH. When the driving signal VGH rises above the effective value, it indicates that the GOA circuit 200 is ready to start working. At this time, in order to avoid affecting the subsequent control logic, the output of the initialization signal VGH1 is stopped, and the GOA circuit 200 works according to the set control strategy.

[0036] It should be noted that the power supply chip 100 only provides the initialization signal when the display device starts to power on. After the driving signal VGH of the GOA circuit 200 rises, the subsequent control is performed by the level converter, and the power consumption of the power supply voltage VDD will not be increased.

[0037] Referring to Figure 2 , Figure 2 The GOA circuit 200 is a 11T1C structure. The discharge control end of the GOA circuit 200 is TRST. When the power supply voltage VDD is powered on and the VGH is not powered on, the power supply chip 100 generates the initialization signal VGH1. At this time, the initialization signal VGH1 will control M7 and M12 to open, and the pull-up node PU is discharged.

[0038] Referring to Figure 3 , Figure 3 The GOA circuit 200 is a 9T1C structure. The discharge control end of the GOA circuit 200 is RESET. When the power supply voltage VDD is powered on and the VGH is not powered on, the power supply chip 100 generates the initialization signal VGH1. At this time, the initialization signal VGH1 will control M2 to open, and the pull-up node PU is discharged.

[0039] According to the power supply chip 100 of the present application, by using the power supply chip 100 to generate the initialization signal VGH1, the generation of the initialization signal VGH1 is independent of the timing controller and the level converter, so that when the display device starts to power on, the pull-up node PU is discharged before the voltage other than the power supply voltage VDD rises, ensuring that the pull-up node PU has no charge when the display device works.

[0040] Referring to Figure 4 In some embodiments, the power supply chip 100 includes a frequency control circuit 110, a switch circuit 120 and a charge pump 130 connected in sequence; the switch circuit 120 is configured to be controlled to be turned on or turned off; and the charge pump 130 is configured to convert the accessed power supply voltage VDD into the initialization signal VGH1 under the control of the frequency control circuit 110.

[0041] In the embodiment, the output terminal of the frequency control circuit 110 is electrically connected with the first terminal of the switch circuit 120, the second terminal of the switch circuit 120 is electrically connected with the control terminal of the charge pump 130, the input terminal of the charge pump 130 is connected with the power supply voltage VDD, and the output terminal of the charge pump 130 is used to provide the initialization signal VGH1. When the switch circuit 120 is turned on, the frequency control circuit 110 and the charge pump 130 are connected; when the switch circuit 120 is turned off, the frequency control circuit 110 and the charge pump 130 are disconnected. The specific structure and principle of the charge pump 130 and the frequency control circuit 110 are mature technologies, and will not be described here.

[0042] In some embodiments, the switch circuit 120 is configured to be connected with the driving signal VGH and turned on or turned off according to the voltage of the driving signal VGH.

[0043] In the embodiment, the switch circuit 120 is directly controlled by the driving signal VGH. When the display device is powered on, the switch circuit 120 is in the turned-on state before the voltage value of the driving signal VGH reaches the effective value; and the switch circuit 120 is in the turned-off state after the voltage value of the driving signal VGH reaches the effective value. Moreover, after the display device is powered on, even if the voltage value of the driving signal VGH drops below the effective value, the switch circuit 120 is in the holding state.

[0044] In other embodiments, the power supply chip 100 can also include a control circuit, which detects the voltage value of the driving signal VGH, controls the switch circuit 120 to be in the turned-on state before the voltage value of the driving signal VGH reaches the effective value, and controls the switch circuit 120 to be in the turned-off state after the voltage value of the driving signal VGH reaches the effective value.

[0045] In some embodiments, the switch circuit 120 includes a MOS tube Q1, the source electrode of the MOS tube Q1 is electrically connected with the frequency control circuit 110, the drain electrode of the MOS tube Q1 is electrically connected with the charge pump 130, and the gate electrode of the MOS tube Q1 is used to connect with the driving signal VGH.

[0046] As an example, the MOS tube Q1 can be a P-type MOS tube. When the voltage value of the driving signal VGH rises above the off voltage of the P-type MOS tube, the P-type MOS tube is turned off, the frequency control circuit 110 and the charge pump 130 are disconnected, and the output of the initialization signal VGH1 is stopped.

[0047] In some embodiments, the frequency control circuit 110 is also electrically connected with the gate electrode of the MOS tube Q1 and is configured to control the MOS tube Q1 to be turned off according to the voltage of the driving signal VGH.

[0048] In the embodiment, the gate of the MOS transistor Q1 is provided with a pin RENS for feeding back the voltage of the driving signal VGH. The frequency control circuit 110 is electrically connected with the pin RENS, so that the voltage applied to the source of the MOS transistor Q1 can be adjusted according to the voltage of the driving signal VGH, and the voltage value of the driving signal VGH when the MOS transistor Q1 is turned off is adjusted, facilitating the design of the time for outputting the initialization signal VGH1.

[0049] In some embodiments, the power supply chip 100 is configured to convert the power supply voltage VDD into a reference voltage for driving a timing controller or a data driving circuit.

[0050] In the embodiment, the power supply chip 100 is a chip independent of the PMIC, and the power supply chip 100 can also be used to generate a reference voltage for driving a timing controller or a data driving circuit, such as AVDD, DVDD, etc. Thus, the hardware density in the PMIC can be reduced, and the heat generation can be reduced.

[0051] The generation of the reference voltage can also be implemented by using a charge pump circuit, and the charge pump circuit has mature technology, which will not be described herein.

[0052] In some embodiments, the power supply chip 100 is configured to convert the power supply voltage VDD into a driving signal VGH.

[0053] In the embodiment, the power supply chip 100 is a chip independent of the PMIC, and the power supply chip 100 can also be used to generate a driving signal VGH. Thus, the hardware density in the PMIC can be reduced, and the heat generation can be reduced.

[0054] In some other embodiments, the power supply chip 100 can also be used to generate an off voltage VHL.

[0055] Similarly, the generation of the driving signal VGH and the off voltage VHL can also be implemented by using a charge pump circuit.

[0056] One embodiment of the present application further provides a display device, which comprises the power supply chip 100 according to the foregoing. The specific structure of the power supply chip 100 can refer to the foregoing embodiments, which will not be described herein.

[0057] According to the display device of the present application, the initialization signal VGH1 is generated by using the power supply chip 100, and the generation of the initialization signal VGH1 is separated from the timing controller and the level shifter, so that the pull-up node PU is discharged before the voltage other than the power supply voltage VDD is started when the display device starts to be powered on, and the pull-up node PU is ensured to have no charge when the display device works.

[0058] Reference Figure 5In some embodiments, the display device includes a display substrate provided with the GOA circuit 200, the discharge control end of the GOA circuit 200 is electrically connected with the cathode of the first diode D1 and the cathode of the second diode D2 respectively, the anode of the first diode D1 is electrically connected with the initialization signal output end of the power supply chip 100, and the anode of the second diode D2 is electrically connected with the initialization signal output end of the level shifter.

[0059] It should be noted that the actual output PIN of L / S refers to the initialization signal output end of the level shifter. After the display device is powered on and runs, the pull-up node PU in the GOA circuit 200 also needs to be discharged. That is, the discharge control end of the GOA circuit 200 needs to be connected with a discharge signal in the state of power-on running, and the discharge signal can be provided by the level shifter.

[0060] Continuing to refer to Figure 2 and Figure 3 , the discharge control end of the GOA circuit 200 refers to TRST( Figure 2 ) and RESET( Figure 3 ) respectively. The cathode of the first diode D1 and the cathode of the second diode D2 are used to form an anti-backflow structure to avoid backflow to the level shifter when the power supply chip 100 outputs the initialization signal, and to avoid backflow to the power supply chip 100 when the level shifter outputs the initialization signal.

[0061] In some embodiments, the level shifter outputs the discharge signal when the voltage value of the driving signal VGH is pulled up to the maximum value, so that the GOA circuit 200 discharges the pull-up node according to the discharge signal.

[0062] Referring to Figure 6 , in the present embodiment, TRST-LS is the input signal of the discharge control end of the GOA circuit 200. During the power-on process, the initialization signal VGH1 is pulled high, TRST-LS is pulled high, the GOA circuit 200 starts to discharge, and the driving signal VGH rises to the maximum value, and the power-on process ends. Before entering the display process, the level shifter outputs the discharge signal, TRST-LS is pulled high again, and the GOA circuit 200 discharges for the second time before entering the work, to ensure that the pull-up node PU is completely discharged.

[0063] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A power supply chip for a display device, characterized in that, The display device includes a GOA circuit. The power chip is configured to convert the power supply voltage into an initialization signal when powered on and transmit the initialization signal to the GOA circuit, so that the GOA circuit discharges the pull-up node according to the initialization signal and stops outputting the initialization signal after the voltage value of the drive signal of the GOA circuit reaches an effective value. The power chip includes a frequency control circuit, a switching circuit, and a charge pump that are electrically connected in sequence. The switching circuit is configured to be turned on or off in a controlled manner; The charge pump is configured to convert the input power supply voltage into the initialization signal under the control of the frequency control circuit; The switching circuit is configured to receive the driving signal. Before the voltage value of the driving signal reaches the effective value, the switching circuit is in a conducting state; after the voltage value of the driving signal reaches the effective value, the switching circuit is in a disconnected state.

2. The power chip according to claim 1, characterized in that, The switching circuit includes a MOSFET, the source of which is electrically connected to the frequency control circuit, the drain of which is electrically connected to the charge pump, and the gate of which is used to receive the drive signal.

3. The power chip according to claim 2, characterized in that, The frequency control circuit is also electrically connected to the gate of the MOS transistor and is configured to control the MOS transistor to turn off according to the voltage of the drive signal.

4. The power chip according to any one of claims 1-3, characterized in that, The power chip is configured to convert the power supply voltage into a reference voltage, which is used to drive a timing controller or a data drive circuit.

5. The power chip according to any one of claims 1-3, characterized in that, The power chip is configured to convert the power supply voltage into the drive signal.

6. A display device, characterized in that, Includes the power supply chip according to any one of claims 1-5.

7. The display device according to claim 6, characterized in that, The display device includes a display substrate, which is provided with a GOA circuit. The discharge control terminal of the GOA circuit is electrically connected to the cathode of a first diode and the cathode of a second diode, respectively. The anode of the first diode is electrically connected to the initialization signal output terminal of the power chip, and the anode of the second diode is electrically connected to the initialization signal output terminal of the level converter.

8. The display device according to claim 7, characterized in that, The level converter outputs a discharge signal when the drive signal voltage value is pulled up to the maximum value, so that the GOA circuit discharges the pull-up node according to the discharge signal.

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