阅读说明：本技术 驱动电路及显示装置 (Drive circuit and display device ) 是由 李浩然 于 2021-08-16 设计创作，主要内容包括：本申请公开了一种驱动电路及显示装置。驱动电路包括第一晶体管,其栅极与第一控制端电性连接,其漏极与第一电压端电性连接,其源极与第一节点电性连接；电感,其第一端与第一节点电性连接,其第二端与第二电压端电性连接；第一二极管,其正极端与接地端电性连接,其负极端与第一节点电性连接；第一电容,其第一端与第二电压端电性连接,其第二端与接地端电性连接；以及放电回路模块,其与第一节点以及接地端电性连接,其用于提供一放电回路对电容进行放电。本申请提供的驱动电路及显示装置,通过放电回路模块提供放电回路对电容进行放电,从而为驱动电路在轻载模式下提供一个逆流放电路径,维持固定的操作频率与振幅,进而能够提高信号的稳定性。(The application discloses a driving circuit and a display device. The driving circuit comprises a first transistor, a second transistor and a third transistor, wherein the grid electrode of the first transistor is electrically connected with the first control end, the drain electrode of the first transistor is electrically connected with the first voltage end, and the source electrode of the first transistor is electrically connected with the first node; the first end of the inductor is electrically connected with the first node, and the second end of the inductor is electrically connected with the second voltage end; a first diode, wherein the positive end of the first diode is electrically connected with the grounding end, and the negative end of the first diode is electrically connected with the first node; a first end of the first capacitor is electrically connected with the second voltage end, and a second end of the first capacitor is electrically connected with the grounding end; and the discharge loop module is electrically connected with the first node and the grounding end and is used for providing a discharge loop to discharge the capacitor. The application provides a drive circuit and a display device, provide the discharge circuit through the discharge circuit module and discharge to the electric capacity to for drive circuit provides a backward flow discharge path under the light load mode, maintain fixed operating frequency and amplitude, and then can improve the stability of signal.)

1. A driver circuit, comprising:

a gate of the first transistor is electrically connected with a first control end, a drain of the first transistor is electrically connected with a first voltage end, and a source of the first transistor is electrically connected with a first node;

a first end of the inductor is electrically connected with the first node, and a second end of the inductor is electrically connected with a second voltage end;

a positive end of the first diode is electrically connected with a grounding end, and a negative end of the first diode is electrically connected with the first node;

a first end of the first capacitor is electrically connected with the second voltage end, and a second end of the first capacitor is electrically connected with the grounding end; and

and the discharge loop module is electrically connected with the first node and the grounding end, and is used for providing a discharge loop to discharge the capacitor.

2. The driving circuit of claim 1, wherein the discharge loop module comprises a second transistor;

the grid electrode of the second transistor is electrically connected with a second control end, the drain electrode of the second transistor is electrically connected with the first node, and the source electrode of the second transistor is electrically connected with the grounding end.

3. The driving circuit as claimed in claim 2, wherein the first transistor is one of an N-type transistor or a P-type transistor, and the second transistor is the other of an N-type transistor or a P-type transistor.

4. The driver circuit of claim 2, wherein the first transistor and the second transistor are both disposed within a power management integrated chip.

5. The driving circuit of claim 1, further comprising a charge pump output module;

the charge pump output module is electrically connected with the first node and used for generating a preset voltage based on the voltage of the first node.

6. The driving circuit of claim 5, wherein the charge pump output module comprises a second capacitor, a second diode, a third diode, and a third capacitor;

the first end of the second capacitor is electrically connected with the first node, the second end of the second capacitor is electrically connected with the positive terminal of the second diode and the negative terminal of the third diode, the negative terminal of the second diode is electrically connected with the grounding terminal, the positive terminal of the third diode is electrically connected with the first end of the third capacitor, and the second end of the third capacitor is electrically connected with the grounding terminal.

7. The driving circuit according to claim 1, wherein the driving circuit comprises a first driving timing, a second driving timing, a third driving timing, and a fourth driving timing;

in the first driving time sequence, the inductor current flows downstream to charge the inductor;

in the second driving time sequence, the inductive current discharges downstream to charge the first capacitor;

in the third driving time sequence, the discharging of the inductor current is finished and the inductor current returns to zero, and the first capacitor charges the inductor through the discharging loop module;

and in the fourth driving time sequence, the inductor is charged by the voltage accessed by the first voltage end.

8. The driving circuit according to claim 7, wherein the first transistor is turned on at the first driving timing and the fourth driving timing; at the second driving timing and the third driving timing, the first transistor is turned off.

9. The driving circuit according to claim 7, wherein the discharging module is turned on at the first driving timing and the fourth driving timing; and the discharging module is cut off at the second driving time sequence and the third driving time sequence.

10. A display device comprising a display panel and the driver circuit according to any one of claims 1 to 9; the display panel is electrically connected with the driving circuit.

Technical Field

The application relates to the technical field of display, in particular to a driving circuit and a display device.

Background

The power management integrated chip used in the driving circuit of the existing display device usually selects an asynchronous step-down circuit to generate 3.3 v. However, the asynchronous buck circuit structure may work in an intermittent mode under a light load condition, and LC oscillation is easily generated, thereby causing signal instability and further affecting the display effect of the display device.

Disclosure of Invention

The application provides a drive circuit and a display device, which can improve the stability of signals.

In a first aspect, the present application provides a driving circuit comprising:

a gate of the first transistor is electrically connected with a first control end, a drain of the first transistor is electrically connected with a first voltage end, and a source of the first transistor is electrically connected with a first node;

a first end of the inductor is electrically connected with the first node, and a second end of the inductor is electrically connected with a second voltage end;

a positive end of the first diode is electrically connected with a grounding end, and a negative end of the first diode is electrically connected with the first node;

a first end of the first capacitor is electrically connected with the second voltage end, and a second end of the first capacitor is electrically connected with the grounding end; and

and the discharge loop module is electrically connected with the first node and the grounding end, and is used for providing a discharge loop to discharge the capacitor.

In the driving circuit provided by the application, the discharge loop module comprises a second transistor;

the grid electrode of the second transistor is electrically connected with a second control end, the drain electrode of the second transistor is electrically connected with the first node, and the source electrode of the second transistor is electrically connected with the grounding end.

In the driving circuit provided by the present application, the first transistor is one of an N-type transistor or a P-type transistor, and the second transistor is the other of the N-type transistor or the P-type transistor.

In the driving circuit provided by the application, the first transistor and the second transistor are both arranged in a power management integrated chip.

In the driving circuit provided by the application, the driving circuit further comprises a charge pump output module;

the charge pump output module is electrically connected with the first node and used for generating a preset voltage based on the voltage of the first node.

In the driving circuit provided by the application, the charge pump output module comprises a second capacitor, a second diode, a third diode and a third capacitor;

the first end of the second capacitor is electrically connected with the first node, the second end of the second capacitor is electrically connected with the positive terminal of the second diode and the negative terminal of the third diode, the negative terminal of the second diode is electrically connected with the grounding terminal, the positive terminal of the third diode is electrically connected with the first end of the third capacitor, and the second end of the third capacitor is electrically connected with the grounding terminal.

In the driving circuit provided by the application, the driving circuit comprises a first driving time sequence, a second driving time sequence, a third driving time sequence and a fourth driving time sequence;

in the first driving time sequence, the inductor current flows downstream to charge the inductor;

in the second driving time sequence, the inductive current discharges downstream to charge the first capacitor;

in the third driving time sequence, the discharging of the inductor current is finished and the inductor current returns to zero, and the first capacitor charges the inductor through the discharging loop module;

and in the fourth driving time sequence, the inductor is charged by the voltage accessed by the first voltage end.

In the driving circuit provided by the present application, the first transistor is turned on at the first driving timing and the fourth driving timing; at the second driving timing and the third driving timing, the first transistor is turned off.

In the driving circuit provided by the present application, the discharging module is turned on at the first driving timing and the fourth driving timing; and the discharging module is cut off at the second driving time sequence and the third driving time sequence.

In a second aspect, the present application also provides a display device comprising a display panel and a driver circuit as claimed in any one of claims 1 to 9; the display panel is electrically connected with the driving circuit.

The application provides a drive circuit and display device, provides a discharge circuit through the discharge circuit module and discharges to the electric capacity to can provide a backward flow discharge route for drive circuit under the light load mode, maintain fixed operating frequency and amplitude, and then can improve the stability of signal.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a first structural schematic diagram of a driving circuit according to an embodiment of the present disclosure;

fig. 2 is a schematic diagram of a second structure of a driving circuit according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of a signal waveform of the driving circuit shown in FIG. 2 under a light load;

FIG. 4 is a schematic diagram of a signal waveform of the driving circuit shown in FIG. 1 under a light load;

fig. 5 is a circuit schematic diagram of a driving circuit according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a third structure provided in the embodiments of the present application;

fig. 7 is another circuit diagram of a driving circuit according to an embodiment of the present disclosure;

fig. 8 is a schematic structural diagram of a display device according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the described embodiments are merely a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. It should be understood that the detailed description and specific examples, while indicating the present application, are given by way of illustration and explanation only, and are not intended to limit the present application. The terms "first", "second", and the like in the claims and in the description of the present application are used for distinguishing between different objects and not for describing a particular order.

The embodiment of the application provides a driving circuit and a display device, which can improve the stability of signals and further improve the display effect of the display device. As described in detail below. It should be noted that the following description of the embodiments is not intended to limit the preferred order of the embodiments. The transistors used in all embodiments of the present application may be thin film transistors or field effect transistors or other devices having the same characteristics.

In addition, the transistors adopted in the embodiment of the application can comprise a P-type transistor and/or an N-type transistor. When the grid electrode of the P-type transistor is at a low level, the source electrode and the drain electrode are conducted; when the grid is at high level, the source and the drain are cut off. The N-type transistor is that when the grid electrode is at high level, the source electrode and the drain electrode are conducted; when the grid is at low level, the source and the drain are cut off.

Referring to fig. 1, fig. 1 is a first structural schematic diagram of a driving circuit according to an embodiment of the present disclosure. As shown in fig. 1, the driving circuit 10 according to the embodiment of the present disclosure includes a first transistor T1, an inductor L, a first diode D1, a first capacitor C1, and a discharging module 101. The gate of the first transistor T1 is electrically connected to the first control terminal M1, the drain of the first transistor T1 is electrically connected to the first voltage terminal a, and the source of the first transistor T1 is electrically connected to the first node d. The first end of the inductor L is electrically connected to the first node d, and the second end of the inductor L is electrically connected to the second voltage terminal B. The positive terminal of the first diode D1 is electrically connected to the ground GND, and the negative terminal of the first diode D1 is electrically connected to the first node D. The first end of the first capacitor C1 is electrically connected to the second voltage terminal B, and the second end of the first capacitor C1 is electrically connected to the ground GND. The discharge circuit module 101 is electrically connected to the first node d and the ground GND. The discharging circuit module 101 is used for providing a discharging circuit to discharge the first capacitor C1.

The first voltage terminal a is a voltage input terminal, and the second voltage terminal B is a voltage output terminal. In the display panel industry, for the existing power management integrated chip, the driving circuit often adopts an asynchronous rectification architecture. The driving circuit 10 provided in the embodiment of the present application adopts an asynchronous rectification architecture, so that the input voltage of the first voltage end a is smaller than the output voltage of the second voltage end B. The input voltage from the first voltage terminal a passes through the first transistor T1, the inductor L and the first diode D1 to complete the step-down operation, and the output voltage is generated at the second voltage terminal B.

If the discharge circuit module 101 is not disposed in the driving circuit 10, the signal of the first node d is unstable. Referring to fig. 2 and fig. 3, fig. 2 is a second structural schematic diagram of a driving circuit according to an embodiment of the present disclosure. Fig. 3 is a schematic diagram of signal waveforms of the driving circuit shown in fig. 2 during light load. Specifically, as shown in fig. 2 and fig. 3, the driving circuit 20 includes a first timing t10, a second timing t20, a third timing t30, and a fourth timing t 40.

When the first transistor T1 is turned on at the first timing T10, the first voltage terminal a charges the inductor L, and the inductor current IL flows downstream; at this time, the inductor current IL flows from the first transistor T1 to the inductor. At a second timing T20, when the first transistor T1 is turned off, the inductor current IL is discharged downstream, and the first capacitor C1 is charged. At the third timing T30, when the first transistor T1 is turned off, the inductor current IL ends discharging to zero, and since there is no discharging loop module 101, there is no path for the first capacitor C1 to discharge, the parasitic element on the line starts to charge and discharge, the parasitic inductor discharges to the parasitic capacitor, and the parasitic capacitor discharges to the parasitic inductor, so that the signal at the first node d generates LC oscillation, which results in one or more times of the turn-on process of the first transistor T1 originally during the period being omitted due to too much energy, which results in unstable signal at the first node d and insufficient driving capability. At the fourth timing T40, when the first transistor T1 is turned off, no current flows through the inductor L after the parasitic element energy is turned to zero, and the potential of the first node d is equal to the potential of the second voltage terminal B.

Further, referring to fig. 4, fig. 4 is a schematic diagram of signal waveforms of the driving circuit shown in fig. 1 during a light load. Specifically, as shown in fig. 1 and 4, the driving circuit 10 includes a first driving timing t1, a second driving timing t2, a third driving timing t3, and a fourth driving timing t 4.

When the first transistor T1 is turned on at the first driving timing T1, the first voltage terminal a charges the inductor L, and the inductor current IL flows downstream; at this time, the inductor current IL flows from the first transistor T1 to the inductor L. At the second driving timing T2, when the first transistor T1 is turned off, the inductor current IL is discharged downstream, and the first capacitor C1 is charged. At the third driving timing T3, when the first transistor T1 is turned off, the inductor current IL ends to zero after discharging, and due to the existence of the discharging loop module 101, the first capacitor C1 may charge the inductor L through the discharging loop module 101, so that the first capacitor C1 is discharged. At a fourth driving timing T4, when the first transistor T1 is turned on, the inductor L is charged by the voltage connected to the first voltage terminal a.

The driving circuit 10 provided in the embodiment of the application provides a discharging loop to discharge the first capacitor C1 through the discharging loop module 101, so that a reverse discharging path can be provided for the driving circuit 10 in a light load mode, a fixed operating frequency and amplitude are maintained, and the stability of a signal can be further improved.

Referring to fig. 5, fig. 5 is a circuit diagram of a driving circuit according to an embodiment of the disclosure. As shown in fig. 1 and 5, the discharge module 101 includes a second transistor T2. The gate of the second transistor T2 is electrically connected to the second control terminal M2, the drain of the second transistor T2 is electrically connected to the first node d, and the source of the second transistor T2 is electrically connected to the ground GND.

The first transistor T1 and the second transistor T2 need to be driven in a complementary manner by a same frequency signal, so that the second transistor T2 is turned off when the first transistor T1 is turned on; when the first transistor T1 is turned off, the second transistor T2 is turned on. In some embodiments, the first transistor T1 is one of an N-type transistor or a P-type transistor, and the second transistor T2 is the other of the N-type transistor or the P-type transistor.

The first transistor T1 and the second transistor T2 are both disposed in the power management ic. In some embodiments, the inductor L, the first diode D1, and the first capacitor C1 are disposed outside of the power management integrated chip. Of course, in other embodiments, the inductor L, the first diode D1, and the first capacitor C1 may be disposed within the power management integrated chip.

Specifically, as shown in fig. 4 and 5, at the first driving timing T1, when the first transistor T1 is turned on and the second transistor T2 is turned off, the first voltage terminal a charges the inductor L, and the inductor current IL flows downstream; at this time, the inductor current IL flows from the first transistor T1 to the inductor L. At the time of the second driving T2, when the first transistor T1 is turned off and the second transistor T2 is turned on, the inductor current IL is discharged downstream to charge the first capacitor C1. At the third driving timing T3, when the first transistor T1 is turned off and the second transistor T2 is turned on, the inductor current IL ends to zero after discharging, and due to the existence of the discharging loop module 101, the first capacitor C1 can charge the inductor L through the discharging loop module 101, so that the first capacitor C1 discharges. At the fourth driving timing T4, when the first transistor T1 is turned on and the second transistor T2 is turned off, the inductor L is charged by the voltage connected to the first voltage terminal a.

The driving circuit 10 provided in the embodiment of the application provides a discharge loop to discharge the first capacitor C1 through the second transistor T2, so as to provide a reverse discharge path for the driving circuit 10 in the light load mode, maintain a fixed operating frequency and amplitude, and further improve the stability of the signal.

Referring to fig. 6, fig. 6 is a schematic structural diagram of a third embodiment of the present disclosure. The drive circuit 30 shown in fig. 6 differs from the drive circuit 10 shown in fig. 1 in that: the driving circuit 30 shown in fig. 6 further includes a charge pump output module 102. The charge pump output module 102 is electrically connected to the first node d, and the charge pump output module 102 is configured to generate a predetermined voltage based on a voltage of the first node d.

It can be understood that the embodiment of the present application uses the signal of the first node d in the driving circuit 10 shown in fig. 1 as the driving voltage of the charge pump output module 102 to generate the preset voltage. Moreover, since the signal of the first node d is stable, the signal of the first node d at this time is used as the driving voltage of the charge pump output module 102, which will not result in insufficient output voltage and will not affect the display effect, and thus the preset voltage output by the charge pump output module 102 can be ensured to be stable.

The driving circuit 30 provided in the embodiment of the application provides a discharging loop to discharge the first capacitor C1 through the discharging loop module 101, so that a reverse discharging path can be provided for the driving circuit 30 in a light load mode, a fixed operating frequency and amplitude are maintained, and the stability of a signal can be further improved; in addition, the driving circuit 30 provided in the embodiment of the present application can also use the signal of the first node d as the driving voltage of the charge pump output module 102 to generate the preset voltage, and since the signal of the first node d is stable, the signal number of the first node d at this time is used as the driving voltage of the charge pump output module 102, which will not cause insufficient output voltage and will not affect the display effect, and thus the stability of the preset voltage output by the charge pump output module 102 can be ensured.

Referring to fig. 7, fig. 7 is another circuit diagram of a driving circuit according to an embodiment of the disclosure. As shown in fig. 6 and 7, the charge pump output module 102 includes a second capacitor C2, a second diode D2, a third diode D3, and a third capacitor C3. The first end of the second capacitor C2 is electrically connected to the first node d. A second end of the second capacitor C2 is electrically connected to the positive terminal of the second diode D2 and the negative terminal of the third diode D3. The cathode terminal of the second diode D2 is electrically connected to the ground GND. The positive terminal of the third diode D3 is electrically connected to the first terminal of the third capacitor C3. The second end of the third capacitor C3 is electrically connected to the ground GND.

It should be noted that, in the embodiment of the present application, the switching signal of the voltage reduction circuit, that is, the signal of the first node D, is used as the input voltage of the charge pump output module, and the characteristic that the voltage across the second capacitor C2 cannot change abruptly and the characteristic that the second diode D2 and the third diode D3 are turned on in one direction are used to obtain the output voltage of the charge pump output module 102.

The driving circuit 30 provided in the embodiment of the application provides a discharge loop to discharge the first capacitor C1 through the second transistor T2, so that a reverse flow discharge path can be provided for the driving circuit 30 in a light load mode, a fixed operating frequency and amplitude are maintained, and the stability of a signal can be further improved; in addition, the driving circuit provided in the embodiment of the present application can also use the signal of the first node d as the driving voltage of the charge pump output module 102 to generate the preset voltage, and since the signal of the first node d is stable, the signal number of the first node d at this time is used as the driving voltage of the charge pump output module 102, which will not cause insufficient output voltage and will not affect the display effect, and thus the stability of the preset voltage output by the charge pump output module 102 can be ensured.

Referring to fig. 8, fig. 8 is a schematic structural diagram of a display device according to an embodiment of the present disclosure. As shown in fig. 8, the display device 100 provided in the embodiment of the present application includes a display panel 200 and a driving circuit 10/20/30. The display panel 200 is electrically connected to the driving circuit 10/20/30. The driver circuit 10/20/30/is the driver circuit described in the above embodiments, and can be referred to the above embodiments.

The display device provided by the embodiment of the application provides a discharge loop to discharge the capacitor through the discharge loop module, so that a reverse flow discharge path can be provided for the driving circuit in a light load mode, fixed operation frequency and amplitude are maintained, and the stability of signals can be improved.

The current limiting circuit provided by the embodiment of the present application is described in detail above, and a specific example is applied in the present application to explain the principle and the implementation manner of the present application, and the description of the above embodiment is only used to help understanding the method and the core idea of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.