Power supply circuit and display panel

Abstract

The invention belongs to the technical field of display driving, and particularly relates to a power supply circuit and a display panel, and the power supply circuit comprises a delay control module which is used for outputting a first control signal during power-on, and continuously outputting a second control signal after outputting the first control signal for a preset time length; the first power supply module is used for converting an output voltage of the external power supply into a first power supply voltage under the action of the first control signal; the second power supply module is used for converting the output voltage of the external power supply into second power supply voltage under the action of the second control signal; the power supply voltage is increased during power-on, the normal working voltage is recovered after power-on, all load modules in the display panel can work normally even if the power-on heavy load voltage drop exists, and therefore the problem of power-on abnormity caused by the power-on heavy load voltage drop is solved, and meanwhile the power-on reliability of the display panel is improved. And the problem that the device is damaged when the load works for a long time under a relatively high starting-up voltage is also avoided.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the technical field of display driving, and particularly relates to a power supply circuit and a display panel. BACKGROUND

[0002] During the start-up phase of an electronic product, each load module needs to be switched from zero state to full load work in a very short time, and the instantaneous load current will show a step increase. This phenomenon is called start-up inrush current. According to the power formula P=UI, when the load current (I) increases sharply, it will cause the supply voltage (U) to drop significantly, forming a transient voltage drop.

[0003] At present, when a display panel encounters a heavy load display screen during start-up, a large transient voltage drop will occur, and the drop amplitude may exceed the lower limit of the normal working voltage, causing the core chip to trigger an under-voltage protection mechanism, thereby causing start-up failure and other abnormal phenomena.

[0004] Therefore, how to improve the abnormal phenomena caused by start-up heavy load voltage drop is a problem to be solved at present. SUMMARY

[0005] The present application provides a power supply circuit and a display panel. By increasing the supply voltage during power-up and restoring the normal working voltage after power-up, the problem of start-up abnormality caused by start-up heavy load voltage drop is solved, and the problem of device damage caused by long-term work of the load at a high start-up voltage is also avoided.

[0006] In a first aspect, an embodiment of the present application provides a power supply circuit, comprising: a delay control module, configured to output a first control signal during power-up, and to continuously output a second control signal after outputting the first control signal for a preset time length; a first power supply module, a control end of the first power supply module being connected to an output end of the delay control module, a first end of the first power supply module being connected to an output end of an external power supply, and a second end of the first power supply module being connected to a power supply end of a subsequent load, configured to convert an output voltage of the external power supply into a first power supply voltage under the action of the first control signal, so as to supply power to the subsequent load by the first power supply voltage; and a second power supply module, a control end of the second power supply module being connected to the output end of the delay control module, a first end of the second power supply module being connected to the output end of the external power supply, and a second end of the second power supply module being connected to the power supply end of the subsequent load, configured to convert the output voltage of the external power supply into a second power supply voltage under the action of the second control signal, so as to supply power to the subsequent load by the second power supply voltage; wherein the first power supply voltage is greater than the second power supply voltage.

[0007] Optionally, the delay control module comprises: a first resistor, a first end of the first resistor being connected to an output end of the external power supply; a first capacitor, a first end of the first capacitor being connected to a second end of the first resistor, and a second end of the first capacitor being grounded; a first transistor, a control end of the first transistor being connected to the first end of the first capacitor; a second resistor, a first end of the second resistor being grounded, and a second end of the second resistor being connected to a first end of the first transistor; a third resistor, a first end of the third resistor being connected to the output end of the external power supply; a second transistor, a control end of the second transistor being connected to the control end of the first transistor, a first end of the second transistor being connected to a second end of the third resistor, and a second end of the second transistor being connected to a second end of the first transistor; wherein the first transistor has a low-level opening voltage, the second transistor has a high-level opening voltage, and the second end of the first transistor or the second end of the second transistor is taken as an output end of the delay control module.

[0008] Optionally, the delay control module comprises: a differential amplifier, a first input end of the differential amplifier being connected to a reference voltage output end of an external power supply, and a second input end of the differential amplifier being connected to a power supply end of the subsequent load, for amplifying a difference between a current supply voltage of the power supply end of the subsequent load and a reference voltage; a comparator, a first input end of the comparator being connected to a reference threshold end, and a second input end of the comparator being connected to an output end of the differential amplifier, for outputting the first control signal or the second control signal according to a comparison result of the voltage difference output by the differential amplifier and the reference threshold.

[0009] Optionally, the first power supply module comprises a third transistor, a control end of the third transistor being connected to an output end of the delay control module, a first end of the third transistor being connected to a first output end of the external power supply, and a second end of the third transistor being connected to the power supply end of the subsequent load; the second power supply module comprises a fourth transistor, a control end of the fourth transistor being connected to the output end of the delay control module, a first end of the fourth transistor being connected to a second output end of the external power supply, and a second end of the fourth transistor being connected to the power supply end of the subsequent load; wherein the third transistor and the fourth transistor have opposite opening voltages, and an output voltage of the first output end of the external power supply is greater than an output voltage of the second output end of the external power supply.

[0010] Optionally, the first power supply module comprises: a first pulse generator configured to generate a first pulse signal with a first duty cycle; a third transistor, a control end of the third transistor being connected with an output end of the delay control module, a first end of the third transistor being connected with an output end of the first pulse generator; a first control tube, a control end of the first control tube being connected with a second end of the third transistor, a first end of the first control tube being grounded; a first inductor, a first end of the first inductor being connected with an output end of the external power supply, a second end of the first inductor being connected with a second end of the first control tube; a first diode, an anode of the first diode being connected with the second end of the first inductor, a cathode of the first diode being connected with a power supply end of the subsequent load; and a second capacitor, a first end of the second capacitor being connected with the cathode of the first diode, a second end of the second capacitor being grounded.

[0011] Optionally, the second power supply module comprises: a second pulse generator configured to generate a second pulse signal with a second duty cycle; a fourth transistor, a control end of the fourth transistor being connected with an output end of the delay control module, a first end of the fourth transistor being connected with an output end of the second pulse generator; a second control tube, a control end of the second control tube being connected with a second end of the fourth transistor, a first end of the second control tube being grounded; a second inductor, a first end of the second inductor being connected with an output end of the external power supply, a second end of the second inductor being connected with a second end of the second control tube; a second diode, an anode of the second diode being connected with the second end of the second inductor, a cathode of the second diode being connected with a power supply end of the subsequent load; and a third capacitor, a first end of the third capacitor being connected with the cathode of the second diode, a second end of the third capacitor being grounded; wherein the turn-on voltages of the third transistor and the fourth transistor are opposite, and the first duty cycle is greater than the second duty cycle.

[0012] Optionally, the second power supply module comprises: a second pulse generator configured to generate a second pulse signal with a second duty cycle; a fourth transistor, a control end of the fourth transistor being connected with an output end of the delay control module, a first end of the fourth transistor being connected with an output end of the second pulse generator; a second control tube, a control end of the second control tube being connected with a second end of the fourth transistor, a first end of the second control tube being grounded, a second end of the second control tube being connected with a second end of the first inductor; wherein the turn-on voltages of the third transistor and the fourth transistor are opposite, and the first duty cycle is greater than the second duty cycle.

[0013] Optionally, the first power supply module further comprises: a third pulse generator configured to generate a third pulse signal with a third duty cycle; a fifth transistor, a control terminal of the fifth transistor being connected with an output terminal of the delay control module, a first terminal of the fifth transistor being connected with an output terminal of the third pulse generator; a third control transistor, a control terminal of the third control transistor being connected with a second terminal of the fifth transistor, a first terminal of the third control transistor being grounded; a third inductor, a first terminal of the third inductor being connected with an output terminal of the external power supply, a second terminal of the third inductor being connected with a second terminal of the third control transistor; and a third diode, an anode of the third diode being connected with the second terminal of the third inductor, a cathode of the third diode being connected with the first terminal of the first inductor; wherein the fifth transistor and the fourth transistor have the same turn-on voltage, and the third duty cycle is greater than the first duty cycle.

[0014] Optionally, the power supply circuit further comprises: a sixth transistor, a control terminal of the sixth transistor being connected with an output terminal of the delay control module, a first terminal of the sixth transistor being connected with an output terminal of the external power supply; a seventh transistor, a control terminal of the seventh transistor being connected with the control terminal of the sixth transistor, a first terminal of the seventh transistor being connected with a second terminal of the sixth transistor, a second terminal of the seventh transistor being grounded; a fourth inductor, a first terminal of the fourth inductor being connected with the first terminal of the seventh transistor, a second terminal of the fourth inductor being connected with a power supply terminal of the subsequent load; and a fourth capacitor, a first terminal of the fourth capacitor being connected with the second terminal of the fourth inductor, a second terminal of the fourth capacitor being grounded; wherein the sixth transistor and the seventh transistor have opposite turn-on voltages.

[0015] In a second aspect, the embodiments of the present application provide a display panel, comprising a display area and a non-display area, the display area comprising a pixel array; the non-display area comprising a timing controller, a gate drive circuit, a source drive circuit and a power supply circuit, the power supply circuit being electrically connected with the timing controller, the gate drive circuit and the source drive circuit respectively, and used for supplying power for the timing controller, the gate drive circuit and the source drive circuit.

[0016] The technical solutions provided by the present application have at least the following beneficial effects:

[0017] The first power supply module in the application converts the output voltage of the external power supply into a first power supply voltage according to the first control signal output by the delay control module when power is turned on, so that the first power supply voltage is used for power supply for starting the load in the later stage; after a preset time length of power-on, the second power supply module converts the output voltage of the external power supply into a second power supply voltage smaller than the first power supply voltage according to the second control signal output by the delay control module, so that the second power supply voltage is used for power supply for normal work of the load in the later stage; therefore, the application increases the power supply voltage when power is turned on, and restores the normal working voltage after power is turned on, so that each load module in the display panel can work normally even if there is a starting overload voltage drop, thereby solving the problem of starting abnormity caused by starting overload voltage drop, and avoiding the problem of device damage caused by long-time work of the load under a high starting voltage. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained from these drawings without creative labor for those skilled in the art.

[0019] Figure 1 A structure schematic diagram of a power supply circuit provided by an embodiment of the application is shown.

[0020] Figure 2 A circuit schematic diagram of a first power supply circuit provided by an embodiment of the application is shown.

[0021] Figure 3 A circuit schematic diagram of a second power supply circuit provided by an embodiment of the application is shown.

[0022] Figure 4 A circuit schematic diagram of a third power supply circuit provided by an embodiment of the application is shown.

[0023] Figure 5 A circuit schematic diagram of a fourth power supply circuit provided by an embodiment of the application is shown.

[0024] Figure 6 A circuit schematic diagram of a fifth power supply circuit provided by an embodiment of the application is shown.

[0025] Figure 7 A circuit schematic diagram of a sixth power supply circuit provided by an embodiment of the application is shown.

[0026] Figure 8 A circuit schematic diagram of a seventh power supply circuit provided by an embodiment of the application is shown.

[0027] BRIEF DESCRIPTION OF DRAWINGS:

[0028] 100, power supply circuit; 110, delay control module; 120, first power supply module; 121, first pulse generator; 122, third pulse generator; 130, second power supply module; 131, second pulse generator; 200, external power supply; 300, load at back stage;

[0029] T1, first transistor; T2, second transistor; T3, third transistor; T4, fourth transistor; T5, fifth transistor; T6, sixth transistor; T7, seventh transistor; Q1, first control tube; Q2, second control tube; Q3, third control tube; R1, first resistor; R2, second resistor; R3, third resistor; C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor; L1, first inductor; L2, second inductor; L3, third inductor; L4, fourth inductor; D1, first diode; D2, second diode; D3, third diode; U1, differential amplifier; U2, comparator; U3, XNOR gate; LX1, first pulse signal; LX2, second pulse signal; LX3, third pulse signal. DETAILED DESCRIPTION

[0030] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations may, however, be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of example implementations to those skilled in the art.

[0031] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the application. One skilled in the relevant art will recognize, however, that the

[0032] The application will be further described with reference to the drawings and specific examples. It is to be understood that the examples described below are illustrative of specific embodiments of the application and are not intended to limit the scope of the application as there are many variations of the application which are possible without departing from the spirit and ideas of the application. In the description of the embodiments, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration various embodiments in which the application can be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the application, and it is to be understood that other embodiments can be utilized and that logical, mechanical and electrical changes can be made without departing from the spirit of the present application. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present application is defined only by the appended claims.

[0033] In a first aspect, embodiments of the present application provide a power supply circuit, and specifically includes the following embodiments:

[0034] Figure 1Fig. 1 shows a structural schematic diagram of a power supply circuit provided by an embodiment of the present application; Fig. 2 shows a structural schematic diagram of a power supply circuit provided by another embodiment of the present application; and Figure 1 As shown, the power supply circuit 100 comprises a delay control module 110, which is configured to output a first control signal at power-on, and continuously output a second control signal after outputting the first control signal for a preset time length.

[0035] It should be noted that the power supply circuit 100 of the present embodiment can be applied in power supply systems in various fields, and the present application takes the power supply system of a display panel as an example. When the display panel is powered on, that is, when the power supply circuit 100 is powered on, the delay control module 110 outputs the first control signal. After the delay control module 110 outputs the first control signal for a preset time length, the second control signal is continuously output. The phases of the first control signal and the second control signal are opposite, that is, when the first control signal is at a low level, the second control signal is at a high level. Conversely, when the first control signal is at a high level, the second control signal is at a low level. In addition, the preset time length can be a fixed time length, for example, the delay control module 110 outputs the first control signal for 1 second, and then continuously outputs the second control signal. The preset time length can also be a time length dynamically detected according to a specific application scenario.

[0036] In the present embodiment, the power supply circuit 100 further comprises a first power supply module 120. The control end of the first power supply module 120 is connected to the output end of the delay control module 110. The first end of the first power supply module 120 is connected to the output end of an external power supply 200. The second end of the first power supply module 120 is connected to the power supply end of a subsequent load 300. The first power supply module 120 is configured to convert the output voltage of the external power supply 200 into a first power supply voltage under the action of the first control signal, so as to supply power to the subsequent load 300 by the first power supply voltage.

[0037] It should be noted that the external power supply 200 is a power supply end for providing an input voltage for the power supply circuit 100, which can be a battery, a direct-current voltage source, and / or a direct-current conversion circuit, etc. The subsequent load 300 is a load end for receiving the output voltage of the power supply circuit 100, which can be a direct-current conversion circuit and / or a gate drive circuit, etc. Therefore, the specific setting position of the power supply circuit 100 in the present embodiment can be flexibly changed according to the actual application scenario.

[0038] In the embodiment, the first power supply module 120 is configured to receive the first control signal output by the delay control module 110, and is configured to convert the output voltage of the external power supply 200 into the first power supply voltage under the action of the first control signal, so as to supply the first power supply voltage to the subsequent load 300; specifically, since there may be a start-up heavy load voltage drop when power is turned on, the demand for the power supply voltage is higher at this time; at this time, the first power supply module 120 converts the output voltage of the external power supply 200 into the first power supply voltage, that is, the output voltage of the external power supply 200 is boosted, so that each load module in the display panel can work normally even if there is a start-up voltage drop, and the normal start-up of the display panel is realized.

[0039] In the embodiment, the power supply circuit 100 further comprises a second power supply module 130, a control end of the second power supply module 130 is connected with the output end of the delay control module 110, a first end of the second power supply module 130 is connected with the output end of the external power supply 200, and a second end of the second power supply module 130 is connected with the power supply end of the subsequent load 300, so as to convert the output voltage of the external power supply 200 into the second power supply voltage under the action of the second control signal, and supply the second power supply voltage to the subsequent load 300.

[0040] It should be noted that the second power supply voltage in the embodiment is less than the first power supply voltage; that is, after a certain length of time of power-on, the second power supply module 130 converts the output voltage of the external power supply 200 into the second power supply voltage under the action of the second control signal output by the delay control module 110, so as to obtain the normal working voltage of the subsequent load 300, thereby avoiding the problem of device damage of the subsequent load 300 working at a high voltage for a long time.

[0041] It should be noted that when the delay control module 110 outputs the first control signal, the second power supply module 130 does not work; similarly, when the delay control module 110 outputs the second control signal, the first power supply module 120 does not work.

[0042] In conclusion, the first power supply module 120 in the application converts the output voltage of the external power supply 200 into the first power supply voltage according to the first control signal output by the delay control module 110 at power-on, so as to supply power for the start-up of the subsequent load 300; after a preset time length of power-on, the second power supply module 130 converts the output voltage of the external power supply 200 into the second power supply voltage smaller than the first power supply voltage according to the second control signal output by the delay control module 110, so as to supply power for the normal operation of the subsequent load 300; therefore, the application increases the power supply voltage at power-on and restores the normal working voltage after power-on, so that each load module in the display panel can work normally even if there is a start-up heavy load voltage drop, thereby solving the problem of start-up abnormality caused by the start-up heavy load voltage drop and avoiding the problem of device damage caused by the long-time operation of the load at a high start-up voltage.

[0043] Figure 2 Fig. 1 shows a circuit schematic diagram of a first power supply circuit provided by an embodiment of the application; as shown in Fig. 1, the first power supply circuit includes an external power supply 200, a delay control module 110, a first power supply module 120 and a subsequent load 300. Figure 2 As shown in Fig. 1, the delay control module 110 of the embodiment includes a first resistor R1, a first capacitor C1, a first transistor T1, a second resistor R2, a third resistor R3 and a second transistor T2; specifically, the first end of the first resistor R1 is connected with the output end of the external power supply 200; the first end of the first capacitor C1 is connected with the second end of the first resistor R1, and the second end of the first capacitor C1 is grounded; the control end of the first transistor T1 is connected with the first end of the first capacitor C1; the first end of the second resistor R2 is grounded, and the second end of the second resistor R2 is connected with the first end of the first transistor T1; the first end of the third resistor R3 is connected with the output end of the external power supply 200; the control end of the second transistor T2 is connected with the control end of the first transistor T1, the first end of the second transistor T2 is connected with the second end of the third resistor R3, and the second end of the second transistor T2 is connected with the second end of the first transistor T1.

[0044] In addition, the turn-on voltage of the first transistor T1 is low, and it can be understood that the first transistor T1 is a P-type MOS tube (Metal-Oxide-Semiconductor Field-Effect Transistor, metal-oxide semiconductor field-effect transistor); the turn-on voltage of the second transistor T2 is high, and it can be understood that the second transistor T2 is an N-type MOS tube, and the second end of the second transistor T2 or the second end of the first transistor T1 is taken as the output end of the delay control module 110.

[0045] It should be noted that the specific working principle of the delay control module 110 provided by the embodiment is as follows:

[0046] (1) Initial stage of power-up: the storage voltage on the first capacitor C1 is 0V, that is, the gate voltage (i.e. control end voltage) of the first transistor T1 and the gate voltage of the second transistor T2 are both equal to 0V, so the first transistor T1 is turned on and the second transistor T2 is turned off, thereby the first control signal output by the delay control module 110 is at low level;

[0047] (2) Charging process: after power-up, the output voltage of the external power supply 200 charges the first capacitor C1 through the first resistor R1, and the gate voltage of the first transistor T1 gradually rises. When the gate voltage rises to the off voltage of the first transistor T1, the first transistor T1 is turned off and the second transistor T2 is turned on, thereby the second control signal output by the delay control module 110 is at high level.

[0048] In the embodiment, the delay time from low level to high level is mainly determined by the first resistor R1 and the first capacitor C1; therefore, the delay time (i.e. preset time length) can be flexibly set by adjusting the parameter values of the first resistor R1 and the first capacitor C1; wherein, the second resistor R2 in the embodiment has a pull-down effect, which makes the second end of the first transistor T1 output low level when the first transistor T1 is turned on; the third resistor R3 in the embodiment has a pull-up effect, which makes the second end of the second transistor T2 output high level when the second transistor T2 is turned on.

[0049] In addition, it should be noted that the external power supply 200 has multiple output ends, and the voltages output by each output end can be the same or different; as shown in Figure 2 , the first end of the first resistor R1 is connected to the output end VDD1 of the external power supply 200, and the first end of the second resistor R2 is connected to the output end VDD2 of the external power supply 200; the output voltages of the output end VDD1 and the output end VDD2 can be the same or different; in addition, the first end of the first resistor R1 and the first end of the second resistor R2 can be connected to the same output end of the external power supply 200.

[0050] As shown in Figure 2 , the first power supply module 120 of the embodiment includes a third transistor T3, the control end of the third transistor T3 is connected to the output end of the delay control module 110, the first end of the third transistor T3 is connected to the first output end of the external power supply 200, and the second end of the third transistor T3 is connected to the power end of the subsequent load 300.

[0051] The second power supply module 130 of the embodiment includes a fourth transistor T4, the control end of the fourth transistor T4 is connected to the output end of the delay control module 110, the first end of the fourth transistor T4 is connected to the second output end of the external power supply 200, and the second end of the fourth transistor T4 is connected to the power end of the subsequent load 300.

[0052] In this embodiment, the turn-on voltages of the third transistor T3 and the fourth transistor T4 are opposite, and the output voltage of the first output terminal of the external power supply 200 is greater than the output voltage of the second output terminal of the external power supply 200 .

[0053] It should be noted that in this embodiment, the third transistor T3 is a P-type MOS transistor and the fourth transistor T4 is an N-type MOS transistor. During power-on, the first control signal output by the delay control module 110 is low, the third transistor T3 is turned on, and the fourth transistor T4 is turned off. Thus, the output voltage VCC1 at the first output terminal of the external power supply 200 is used as the first supply voltage to power the subsequent load 300 through the turned-on third transistor T3. After a preset power-on time, the second control signal output by the delay control module 110 is high, the third transistor T3 is turned off, and the fourth transistor T4 is turned on. Thus, the output voltage VCC2 at the second output terminal of the external power supply 200 is used as the second supply voltage to power the subsequent load 300 through the turned-on fourth transistor T4. Because the output voltage of the first output terminal of the external power supply 200 is greater than the output voltage of the second output terminal of the external power supply 200, the first supply voltage is greater than the second supply voltage. This achieves the purpose of increasing the supply voltage during power-on and restoring the normal operating voltage after power-on. This not only solves the problem of abnormal startup caused by heavy load voltage drop during startup, but also avoids the problem of component damage caused by long-term operation of the load at a high startup voltage.

[0054] Figure 3 FIG2 is a circuit diagram of a second power supply circuit provided in an embodiment of the present application; Figure 3 and Figure 2 The difference lies in the specific structure of the delay control module 110; Figure 3 As shown, the delay control module 110 of this embodiment includes a differential amplifier U1 and a comparator U2; a first input terminal of the differential amplifier U1 is connected to the reference voltage output terminal of the external power supply 200, and a second input terminal of the differential amplifier U1 is connected to the power supply terminal of the subsequent load 300, for amplifying the difference between the current supply voltage of the power supply terminal of the subsequent load 300 and the reference voltage; a first input terminal of the comparator U2 is connected to the reference threshold terminal, and a second input terminal of the comparator U2 is connected to the output terminal of the differential amplifier U1, for outputting a first control signal or a second control signal according to a comparison result between the voltage difference output by the differential amplifier U1 and the reference threshold.

[0055] It should be noted that the reference voltage outputted by the reference voltage output terminal of the external power supply 200 can be the normal operating voltage of the downstream load 300, i.e., the second supply voltage. During the initial power-on phase, if the current supply voltage at the voltage terminal of the downstream load 300 is less than the reference voltage due to the unloading of the downstream load 300, the difference between the current supply voltage and the reference voltage is amplified by the differential amplifier U1, and the voltage difference is then input into the comparator U2 for comparison with a reference threshold. When the voltage difference is greater than the reference threshold, the comparator U2 outputs a first control signal. Conversely, when the voltage difference is less than or equal to the reference threshold, the comparator U2 outputs a second control signal. In this embodiment, the reference threshold can be set based on the amplification factor of the differential amplifier U1. Furthermore, the reference threshold terminal can be a voltage output terminal of the external power supply 200, or a triangular wave or square wave output terminal. Figure 3 The working principle of the third transistor T3 and the fourth transistor T4 is the same as Figure 2 The same, no longer repeated here.

[0056] Figure 4 FIG. 1 is a circuit diagram of a third power supply circuit 100 provided in an embodiment of the present application; FIG. Figure 4 As shown, the delay control module 110 of this embodiment includes an XOR gate U3, which compares the voltages at two adjacent moments to determine whether the current phase is the startup phase or the stable phase; Figure 4 Vt1 represents the input voltage of the subsequent load 300 at time t1, and Vt2 represents the input voltage of the subsequent load 300 at time t2; if Vt1 and Vt2 are different, it means that the voltage is unstable, that is, it is in the startup stage, and the OR gate U3 outputs a low-level control signal, so that a higher output voltage is obtained through the first power supply module 120; on the contrary, if Vt1 and Vt2 are the same, it means that the voltage is stable, that is, it is in the stable stage, and the OR gate U3 outputs a high-level control signal, so that a lower output voltage is obtained through the second power supply module 130.

[0057] In one embodiment, the delay control module 110 may further include a timing chip, and the delay duration is controlled by setting a software program inside the timing chip.

[0058] In another embodiment, the delay control module 110 may further include a comparator, which determines whether the current state is the startup phase or the stable phase by comparing the voltages at two adjacent moments; Figure 4 The XNOR gate in is replaced by a voltage comparator. The specific output logic is the same and will not be described here.

[0059] Figure 5 FIG. 1 is a circuit diagram of a fourth power supply circuit provided in an embodiment of the present application; Figure 5 and Figure 2The difference between the first power supply module 120 and the second power supply module 130 lies in different specific structures; as shown in the figure, Figure 5 The first power supply module 120 of the embodiment includes a first pulse generator 121, a third transistor T3, a first control tube Q1, a first inductor L1 and a first diode D1; specifically, the first pulse generator 121 is used to generate a first pulse signal LX1 with a first duty cycle; the control end of the third transistor T3 is connected with the output end of the delay control module 110, and the first end of the third transistor T3 is connected with the output end of the first pulse generator 121; the control end of the first control tube Q1 is connected with the second end of the third transistor T3, and the first end of the first control tube Q1 is grounded; the first end of the first inductor L1 is connected with the output end of the external power supply 200, and the second end of the first inductor L1 is connected with the second end of the first control tube Q1; the anode of the first diode D1 is connected with the second end of the first inductor L1, and the cathode of the first diode D1 is connected with the power supply end of the subsequent load 300.

[0060] It should be noted that the first control tube Q1 of the embodiment is controlled by the first pulse signal LX1 to periodically turn on and turn off, so as to realize the adjustment of the output voltage; taking the first control tube Q1 as an N-type MOS tube as an example, the working principle of the first power supply module 120 of the embodiment is described in detail:

[0061] (1) The on phase of the first control tube Q1 (i.e. the charging phase): when the third transistor T3 is opened by the first control signal output by the delay control module 110, the first pulse signal LX1 generated by the first pulse generator 121 acts on the gate (i.e. the control end) of the first control tube Q1; during the high level period of the first pulse signal LX1, the first control tube Q1 is turned on, and the first diode D1 is disconnected due to the grounded anode; at this time, the circuit of the first power supply module 120 is equivalent to: first inductor L1→first control tube Q1→ground end; the output voltage of the external power supply 200 is stored in the first inductor L1.

[0062] (2) The off phase of the first control tube Q1 (i.e. the discharging phase): during the low level period of the first pulse signal LX1, the first control tube Q1 is turned off, and the inductor current generates a reverse electromotive force (polarity reversal) due to the sudden change of the magnetic field, and the first diode D1 is forwardly conducted; at this time, the circuit of the first power supply module 120 is equivalent to: first inductor L1→first diode D1→subsequent load 300; the output voltage of the external power supply 200 and the energy stored in the first inductor L1 are transmitted to the subsequent load 300 through the first diode D1, so that the first power supply voltage output by the first power supply module 120 at this time will be greater than the output voltage of the external power supply 200 module.

[0063] Therefore, the first control tube Q1 is periodically switched by the first pulse signal LX1 in the embodiment, and the inductor continuously stores and releases energy, so that the first power supply voltage is stable. The first power supply voltage is controlled by the duty cycle (the ratio of the on time to the period) of the first pulse signal LX1, that is, the greater the first duty cycle (the longer the on time), the greater the first power supply voltage.

[0064] In the embodiment, the first inductor L1 is used as a core energy storage element, and stores energy when the first control tube Q1 is turned on, and releases energy when the first control tube Q1 is turned off, so that the current changes smoothly and the current ripple of the input and output is reduced. The first diode D1 in the embodiment is turned on when the first control tube Q1 is turned off, so as to ensure that the energy is transmitted to the output end and prevent the current from flowing backward; and the first diode D1 is turned off when the first control tube Q1 is turned on, so as to avoid the input power supply being directly short-circuited to the ground.

[0065] In an embodiment, the first power supply module 120 further includes a second capacitor C2, a first end of the second capacitor C2 being connected to the cathode of the first diode D1, and a second end of the second capacitor C2 being grounded. Specifically, the second capacitor C2 in the embodiment supplies power to the subsequent load 300 when the first control tube Q1 is turned on, stores the energy released by the inductor when the first control tube Q1 is turned off, reduces the output voltage ripple, and maintains the output voltage stable through charging and discharging.

[0066] As shown in FIG. 1, Figure 5 As shown in FIG. 1,

[0067] In an embodiment, the second power supply module 130 further includes a third capacitor C3, a first end of the third capacitor C3 being connected to the cathode of the second diode D2, and a second end of the third capacitor C3 being grounded. Specifically, the third capacitor C3 in the embodiment supplies power to the subsequent load 300 when the second control tube Q2 is turned on, stores the energy released by the inductor when the second control tube Q2 is turned off, reduces the output voltage ripple, and maintains the output voltage stable through charging and discharging.

[0068] In this embodiment, the turn-on voltages of the third transistor T3 and the fourth transistor T4 are opposite. For example, when the third transistor T3 is a P-type MOS transistor, the fourth transistor T4 is an N-type MOS transistor. That is, when the first power supply module 120 is operating, the second power supply module 130 is disconnected; conversely, when the second power supply module 130 is operating, the first power supply module 120 is disconnected. The circuit structure of the second power supply module 130 in this embodiment is identical to that of the first power supply module 120, differing only in that the duty cycles of the pulse signals generated by the first pulse generator 121 and the second pulse generator 131 are different. As can be seen from the above description of the operating principle of the first power supply module 120, different duty cycles result in different output voltages. Therefore, in this embodiment, when the first duty cycle is greater than the second duty cycle, the first supply voltage output by the first power supply module 120 is greater than the second supply voltage output by the second power supply module 130, thereby increasing the supply voltage during power-up and restoring the normal operating voltage after power-up. This not only solves the problem of abnormal startup caused by a heavy load voltage drop during startup, but also avoids the problem of component damage caused by the load operating at a high startup voltage for a long time. The working principle of the second power supply module 130 in this embodiment refers to the working principle of the first power supply module 120 described above, and will not be repeated here.

[0069] Figure 6 FIG. 1 is a circuit diagram of a fifth power supply circuit provided in an embodiment of the present application; Figure 6 and Figure 5 The difference is that the second power supply module 130 lacks the second inductor L2 and the second diode D2; Figure 6 As shown, the second power supply module 130 includes: a second pulse generator 131, a fourth transistor T4 and a second control tube Q2; specifically, the second pulse generator 131 is used to generate a second pulse signal LX2 with a second duty cycle; the control end of the fourth transistor T4 is connected to the output end of the delay control module 110, and the first end of the fourth transistor T4 is connected to the output end of the second pulse generator 131; the control end of the second control tube Q2 is connected to the second end of the fourth transistor T4, the first end of the second control tube Q2 is grounded, and the second end of the second control tube Q2 is connected to the second end of the first inductor L1; wherein, the turn-on voltages of the third transistor T3 and the fourth transistor T4 are opposite, and the first duty cycle is greater than the second duty cycle.

[0070] It should be noted that the first power supply module 120 and the second power supply module 130 in this embodiment share the first inductor L1 and the first diode D1. Figure 5 On the same basis as the embodiment shown, one inductor and one diode device are eliminated, thereby reducing the volume and cost of the power supply circuit 100 .

[0071] Figure 7A circuit schematic diagram of a sixth power supply circuit provided by the embodiment of the application is shown in the figure; Figure 7 Compared with Figure 6 The difference lies in that: Figure 7 The first power supply module 120 in the embodiment of the application adds a third pulse generator 122, a fifth transistor T5, a third control tube Q3, a third inductor L3 and a third transistor T3 on the basis of Figure 6 Specifically, the third pulse generator 122 is configured to generate a third pulse signal LX3 with a third duty cycle; the control end of the fifth transistor T5 is connected with the output end of the delay control module 110, and the first end of the fifth transistor T5 is connected with the output end of the third pulse generator 122; the control end of the third control tube Q3 is connected with the second end of the fifth transistor T5, and the first end of the third control tube Q3 is grounded; the first end of the third inductor L3 is connected with the output end of the external power supply 200, and the second end of the third inductor L3 is connected with the second end of the third control tube Q3; the anode of the third diode D3 is connected with the second end of the third inductor L3, and the cathode of the third diode D3 is connected with the first end of the first inductor L1; the opening voltages of the fifth transistor T5 and the fourth transistor T4 are the same, and the third duty cycle is greater than the first duty cycle.

[0072] It should be noted that, taking the third transistor T3 and the fifth transistor T5 as P-type MOS tubes as an example, the working principle of the first power supply module 120 of the embodiment is as follows: when the first control signal output by the delay control module 110 is a low level, the third transistor T3 and the fifth transistor T5 are opened at the same time, the third control tube Q3 is periodically switched by the third pulse signal LX3 output by the third pulse generator 122, the third inductor L3 continuously stores and releases energy, and the output voltage of the external power supply 200 is converted into an intermediate voltage; the first control tube Q1 is periodically switched by the first pulse signal LX1 output by the first pulse generator 121, the first inductor L1 continuously stores and releases energy, and the intermediate voltage is converted into the first power supply voltage; for example, the output voltage VCC of the external power supply 200 of the embodiment is 5V, the intermediate voltage Vgh0 converted by the third pulse signal LX3 is 15V, and finally the first power supply voltage Vgh1 converted by the first pulse signal LX1 is 30V, so that the voltage lifting from 5V to 15V and then to 30V reduces the voltage lifting span compared with the voltage lifting from 5V directly to 30V, thereby improving the stability and variability of voltage conversion.

[0073]

[0074] A circuit schematic diagram of a seventh power supply circuit provided by the embodiment of the application is shown in the figure; Figure 8 Compared with Figure 8 The difference lies in that: Figures 1-7 The difference lies in that: Figure 8The power supply circuit 100 further comprises a sixth transistor T6, a seventh transistor T7, a fourth inductor L4 and a fourth capacitor C4 on the basis of the other power supply circuits 100.

[0075] Specifically, the control end of the sixth transistor T6 is connected with the output end of the delay control module 110, and the first end of the sixth transistor T6 is connected with the output end of the external power supply 200; the control end of the seventh transistor T7 is connected with the control end of the sixth transistor T6, the first end of the seventh transistor T7 is connected with the second end of the sixth transistor T6, and the second end of the seventh transistor T7 is grounded; the first end of the fourth inductor L4 is connected with the first end of the seventh transistor T7, and the second end of the fourth inductor L4 is connected with the power supply end of the subsequent load 300; the first end of the fourth capacitor C4 is connected with the second end of the fourth inductor L4, and the second end of the fourth capacitor C4 is grounded; the turn-on voltages of the sixth transistor T6 and the seventh transistor T7 are opposite.

[0076] It should be noted that, from the foregoing embodiments, it can be known that the circuit structure of the delay control module 110 of the present application includes at least three embodiments (i.e., shown in Figure 2 、 Figure 3 and Figure 4 ), the first power supply module 120 includes at least three embodiments (i.e., shown in Figure 3 、 Figure 5 and Figure 7 ), and the second power supply module 130 also includes at least three embodiments (i.e., shown in Figure 3 、 Figure 5 and Figure 6 ), and different embodiments of each module can be combined with each other, and examples of combination and drawings are not given here; in addition, Figure 8 only one embodiment of the delay control module 110 and additional technical features are shown, and the first power supply module 120 and the second power supply module 130 are not shown for the sake of simple drawings, but in actual application, the embodiments shown in Figure 8 should include the first power supply module 120 and the second power supply module 130.

[0077] Here, taking the delay control module 110 comprising a differential amplifier U1 and a comparator U2 as an example, the working principle of the power supply circuit 100 of the present embodiment is described in detail:

[0078] (1) the voltage difference between the current supply voltage Vin of the load 300 (i.e. the current output voltage of the power supply circuit 100) and the reference voltage Vref output by the external voltage is input to the comparator U2 through the differential amplifier U1, and the comparator U2 compares the voltage difference with the triangular wave (i.e. the reference threshold) to determine the pulse width of the output signal and control the output voltage. Alternatively, the comparator U2 generates by comparing the voltage error signal from the current supply voltage and the reference voltage with a constant sawtooth slope waveform. The slope is started by a clock signal from an oscillator, and good noise margin performance is obtained with a fixed slope amplitude, the voltage regulation is independent of the output current; the use of voltage mode requires a fixed, predictable switching frequency, which is also useful when there can be large output load variations.

[0079] (2) the on and off of the sixth transistor T6 and the seventh transistor T7 are controlled by the output signal of the comparator U2, specifically: if the current supply voltage is less than the reference voltage, the delay control module 110 outputs a low level to turn on the sixth transistor T6, and the output voltage of the external power supply 200 charges the fourth inductor L4 and the fourth capacitor C4, thereby pulling up the output voltage of the power supply circuit 100, so that the voltage is not pulled down abnormally during power-on or heavy load picture switching; if the current supply voltage is equal to or greater than the reference voltage, the delay control module 110 outputs a high level to turn on the seventh transistor T7, and the output voltage of the external power supply 200 is not received and discharged through the fourth inductor L4 and the fourth capacitor C4, thereby reducing the output voltage of the power supply circuit 100, so that the normal working voltage is restored after the power is stabilized.

[0080] At the same time, the power supply circuit 100 of the embodiment also adjusts the current output voltage through the first power supply module 120 and the second power supply module 130; therefore, the embodiment adjusts the current output voltage through the sixth transistor T6, the seventh transistor T7, the fourth inductor L4 and the fourth capacitor C4 in cooperation with the first power supply module 120 and the second power supply module 130, thereby improving the voltage regulation accuracy of the power supply circuit 100.

[0081] In a second aspect, the embodiment of the present application provides a display panel, comprising a display area and a non-display area, wherein the display area comprises a pixel array; the non-display area comprises a timing controller, a gate drive circuit, a source drive circuit and a power supply circuit, the power supply circuit is electrically connected with the timing controller, the gate drive circuit and the source drive circuit respectively, and is used for supplying power for the timing controller, the gate drive circuit and the source drive circuit.

[0082] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and should not be construed as implying or suggesting relative importance or an implied order of magnitude. Thus, features defined with "first", "second", "third" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise expressly and specifically limited.

[0083] In the description of the present application, the description referring to the terms "some embodiments", "exemplarily" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are contained in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the person skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples, without contradiction.

[0084] Although the embodiments of the present application have been shown and described above, it is to be understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and the person skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application, and any changes or modifications made in accordance with the claims and the specification of the present application shall be within the scope of the present application.

Claims

1. A power supply circuit, characterized in that: The power supply circuit includes: a delay control module, configured to output a first control signal upon power-up, and continuously output a second control signal after outputting the first control signal for a preset time period; a first power supply module, wherein a control end of the first power supply module is connected to the output end of the delay control module, a first end of the first power supply module is connected to the output end of the external power supply, and a second end of the first power supply module is connected to the power supply end of the subsequent load, and is configured to convert the output voltage of the external power supply into a first power supply voltage under the action of the first control signal, so that the first power supply voltage is used to power the subsequent load; a second power supply module, wherein a control end of the second power supply module is connected to the output end of the delay control module, a first end of the second power supply module is connected to the output end of the external power supply, and a second end of the second power supply module is connected to the power supply end of the subsequent load, and is configured to convert the output voltage of the external power supply into a second power supply voltage under the action of the second control signal, so that the second power supply voltage is used to power the subsequent load; The first supply voltage is greater than the second supply voltage.

2. The power supply circuit according to claim 1, wherein: The delay control module includes: a first resistor, wherein a first end of the first resistor is connected to an output end of the external power supply; a first capacitor, wherein a first end of the first capacitor is connected to the second end of the first resistor, and a second end of the first capacitor is grounded; a first transistor, wherein a control terminal of the first transistor is connected to a first terminal of the first capacitor; a second resistor, wherein a first end of the second resistor is grounded, and a second end of the second resistor is connected to the first end of the first transistor; a third resistor, a first end of the third resistor being connected to the output end of the external power supply; a second transistor, wherein a control terminal of the second transistor is connected to the control terminal of the first transistor, a first terminal of the second transistor is connected to the second terminal of the third resistor, and a second terminal of the second transistor is connected to the second terminal of the first transistor; The turn-on voltage of the first transistor is a low level, the turn-on voltage of the second transistor is a high level, and the second end of the first transistor or the second end of the second transistor is used as the output end of the delay control module.

3. The power supply circuit according to claim 1, wherein: The delay control module includes: a differential amplifier, wherein a first input terminal of the differential amplifier is connected to a reference voltage output terminal of an external power supply, and a second input terminal of the differential amplifier is connected to a power supply terminal of the subsequent load, and is used to amplify a difference between a current supply voltage at the power supply terminal of the subsequent load and a reference voltage; A comparator, wherein a first input terminal of the comparator is connected to a reference threshold terminal, and a second input terminal of the comparator is connected to the output terminal of the differential amplifier, and is used to output the first control signal or the second control signal based on a comparison result between a voltage difference output by the differential amplifier and a reference threshold.

4. The power supply circuit according to claim 2 or 3, characterized in that: The first power supply module includes a third transistor, a control end of the third transistor is connected to the output end of the delay control module, a first end of the third transistor is connected to the first output end of the external power supply, and a second end of the third transistor is connected to the power supply end of the subsequent load; The second power supply module includes a fourth transistor, a control end of the fourth transistor is connected to the output end of the delay control module, a first end of the fourth transistor is connected to the second output end of the external power supply, and a second end of the fourth transistor is connected to the power supply end of the subsequent load; The turn-on voltages of the third transistor and the fourth transistor are opposite to each other, and the output voltage of the first output terminal of the external power supply is greater than the output voltage of the second output terminal of the external power supply.

5. The power supply circuit according to claim 2 or 3, characterized in that: The first power supply module includes: A first pulse generator, configured to generate a first pulse signal having a first duty cycle; a third transistor, wherein a control terminal of the third transistor is connected to the output terminal of the delay control module, and a first terminal of the third transistor is connected to the output terminal of the first pulse generator; a first control tube, wherein a control end of the first control tube is connected to the second end of the third transistor, and a first end of the first control tube is grounded; a first inductor, wherein a first end of the first inductor is connected to the output end of the external power supply, and a second end of the first inductor is connected to the second end of the first control transistor; a first diode, wherein an anode of the first diode is connected to the second end of the first inductor, and a cathode of the first diode is connected to a power supply terminal of the subsequent load; A second capacitor, wherein a first end of the second capacitor is connected to the cathode of the first diode, and a second end of the second capacitor is grounded.

6. The power supply circuit according to claim 5, characterized in that: The second power supply module includes: a second pulse generator, configured to generate a second pulse signal having a second duty cycle; a fourth transistor, wherein a control terminal of the fourth transistor is connected to the output terminal of the delay control module, and a first terminal of the fourth transistor is connected to the output terminal of the second pulse generator; a second control tube, wherein a control terminal of the second control tube is connected to the second terminal of the fourth transistor, and a first terminal of the second control tube is grounded; a second inductor, wherein a first end of the second inductor is connected to the output end of the external power supply, and a second end of the second inductor is connected to the second end of the second control transistor; a second diode, wherein an anode of the second diode is connected to the second end of the second inductor, and a cathode of the second diode is connected to the power supply end of the subsequent load; a third capacitor, wherein a first end of the third capacitor is connected to the cathode of the second diode, and a second end of the third capacitor is grounded; The turn-on voltages of the third transistor and the fourth transistor are opposite, and the first duty cycle is greater than the second duty cycle.

7. The power supply circuit according to claim 5, characterized in that: The second power supply module includes: a second pulse generator, configured to generate a second pulse signal having a second duty cycle; a fourth transistor, wherein a control terminal of the fourth transistor is connected to the output terminal of the delay control module, and a first terminal of the fourth transistor is connected to the output terminal of the second pulse generator; a second control tube, wherein a control end of the second control tube is connected to the second end of the fourth transistor, a first end of the second control tube is grounded, and a second end of the second control tube is connected to the second end of the first inductor; The turn-on voltages of the third transistor and the fourth transistor are opposite, and the first duty cycle is greater than the second duty cycle.

8. The power supply circuit according to claim 5, characterized in that: The first power supply module further includes: a third pulse generator, configured to generate a third pulse signal having a third duty cycle; a fifth transistor, wherein a control terminal of the fifth transistor is connected to the output terminal of the delay control module, and a first terminal of the fifth transistor is connected to the output terminal of the third pulse generator; a third control tube, wherein a control terminal of the third control tube is connected to the second terminal of the fifth transistor, and a first terminal of the third control tube is grounded; a third inductor, wherein a first end of the third inductor is connected to the output end of the external power supply, and a second end of the third inductor is connected to the second end of the third control transistor; a third diode, wherein an anode of the third diode is connected to the second end of the third inductor, and a cathode of the third diode is connected to the first end of the first inductor; The turn-on voltages of the fifth transistor and the fourth transistor are the same, and the third duty cycle is greater than the first duty cycle.

9. The power supply circuit according to any one of claims 1 to 8, characterized in that: The power supply circuit further includes: a sixth transistor, wherein a control terminal of the sixth transistor is connected to the output terminal of the delay control module, and a first terminal of the sixth transistor is connected to the output terminal of the external power supply; a seventh transistor, wherein a control terminal of the seventh transistor is connected to the control terminal of the sixth transistor, a first terminal of the seventh transistor is connected to the second terminal of the sixth transistor, and a second terminal of the seventh transistor is grounded; a fourth inductor, wherein a first end of the fourth inductor is connected to the first end of the seventh transistor, and a second end of the fourth inductor is connected to the power supply end of the subsequent load; a fourth capacitor, wherein a first end of the fourth capacitor is connected to the second end of the fourth inductor, and a second end of the fourth capacitor is grounded; The turn-on voltages of the sixth transistor and the seventh transistor are opposite.

10. A display panel comprising a display area and a non-display area, characterized in that: The display area includes a pixel array; The non-display area includes a timing controller, a gate drive circuit, a source drive circuit and a power supply circuit according to any one of claims 1 to 9, and the power supply circuit is electrically connected to the timing controller, the gate drive circuit and the source drive circuit, respectively, for supplying power to the timing controller, the gate drive circuit and the source drive circuit.

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