Charge pump control circuit, display panel, and display device

Abstract

The present application discloses a charge pump control circuit, a display panel, and a display device, the charge pump control circuit including a first sampling identification module (10) that samples an input voltage of a series branch circuit (60), and outputs a first switching signal when it is determined that the series branch circuit (60) is in a heavy load operating state based on the input voltage, and outputs a second switching signal when the input voltage is in a light load operating state, a PWM module (20) that operates a first switching circuit (71) by outputting a PWM signal when the first switching signal is received, and a PFM module (30) that operates the first switching circuit (71) by outputting a PFM signal when the second switching signal is received.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to a Chinese patent application filed on April 24, 2022, bearing application number 202210434013.4, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of mini-LED driving, and in particular to a charge pump control circuit, a display panel and a display device. [Background technology]

[0003] Currently, mini-LEDs range in size from 50 to 200μm and can be used as a backlight source for LCDs, so they are expected to have a large market share in the fields of TVs, displays, laptops, etc. Compared to LCD and OLED displays, mini-LEDs have the advantages of high brightness, low power consumption, long life, and excellent thermal stability, but they have the problem of high power consumption of the display panel because multiple mini-LEDs are installed in series. Summary of the Invention [Means for solving the problem]

[0004] The main objective of the present application is to provide a charge pump control circuit for use in a display panel, comprising: a first sampling identification module, a PWM module, and a PFM module; The display panel includes: A series branch circuit including a plurality of mini-LEDs connected in series; a charge pump module having an output terminal connected to the input terminal of the series branch circuit and having a first switching circuit for regulating an output voltage; The first sampling identification module has a sampling terminal connected to the series branch circuit, samples an input voltage of the series branch circuit, and outputs a first switching signal when it is determined that the series branch circuit is in a heavy load operating state based on the input voltage of the series branch circuit, and outputs a second switching signal when it is determined that the series branch circuit is in a light load operating state based on the input voltage of the series branch circuit. The PWM module has a controlled terminal connected to the output terminal of the first sampling identification module and an output terminal connected to the controlled terminal of the first switching circuit, and when receiving the first switching signal, outputs a PWM signal to operate the first switching circuit; The PFM module has a controlled terminal connected to the output terminal of the first sampling identification module and an output terminal connected to the controlled terminal of the first switching circuit, and operates the first switching circuit by outputting a PFM signal when it receives the second switching signal.

[0005] The present application further proposes a display panel, the display panel comprising: A series branch circuit including a plurality of mini-LEDs connected in series; a charge pump module having an output terminal connected to the input terminal of the series branch circuit, the charge pump module having a first switching circuit for regulating an output voltage of the charge pump module.

[0006] In the above-described charge pump control circuit, the charge pump control circuit is connected to the series branch circuit and the first switching circuit.

[0007] The present application further proposes a display device including such a display panel.

[0008] The technical solution of the present application adopts a first sampling identification module, a PWM module and a PFM module, and uses the first sampling identification module to sample the input voltage of the series branch circuit to generate a corresponding voltage sampling signal; when it is determined according to the voltage sampling signal that the series branch circuit is in a heavy load operating state, it controls the PWM module to output a PWM signal by outputting a first switching signal to operate the first switching circuit; when it is determined according to the voltage sampling signal that the series branch circuit is in a light load operating state, it controls the PFM module to output a PFM signal by outputting a second switching signal to operate the first switching circuit. By integrating a PWM control function and a PFM control function, the charge pump control circuit of the present application can switch between the PWM module and the PFM module at any time depending on the heavy load operating state or the light load operating state of the series branch circuit while the display device continues to play images. Therefore, by performing PFM control on the first switching circuit in the light load operating state, it is not necessary to operate the first switching circuit under PWM control for a long period of time, and the conduction loss of the first switching circuit is reduced, thereby reducing the operating power consumption of the charge pump module and solving the problem of high power consumption of mini-LED display panels.

[0009] In order to more clearly describe the technical solutions of the embodiments of the present application and the prior art, the following briefly introduces the accompanying drawings required for the description of the embodiments or the prior art. It is obvious that the accompanying drawings in the following description are only some of the embodiments of the present application, and those skilled in the art can obtain other accompanying drawings according to the structures shown in these accompanying drawings without creative work. [Brief description of the drawings]

[0010] [Figure 1] 1 is a module schematic diagram of an embodiment of a charge pump control circuit according to the present application. [Diagram 2] 1 is a circuit schematic diagram of an embodiment of a charge pump control circuit according to the present invention; [Diagram 3] FIG. 2 is a circuit schematic diagram of another embodiment of the charge pump control circuit of the present application. [Figure 4] FIG. 2 is a circuit schematic diagram of an embodiment of a display panel according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The realization of the object, the function features and advantages of the present invention will be further explained in combination with the embodiments with reference to the attached drawings.

[0012] The following will clearly and completely describe the technical solutions in the embodiments of the present application in combination with the drawings in the embodiments of the present application. It is clear that the described embodiments are not all the embodiments of the present application, but only some of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments that a person skilled in the art can obtain without performing creative work fall within the scope of protection of the present application.

[0013] In addition, the descriptions such as "first" and "second" in the embodiments of the present application are used for explanatory purposes only and should not be understood as indicating or implying the relative importance thereof or implicitly specifying the number of technical features presented. Thus, a feature limited to "first" or "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other. However, this is premised on the fact that a person skilled in the art can realize it. If a combination of technical solutions causes a contradiction or cannot be realized, it should be understood that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present application. First Example

[0014] This application proposes a charge pump control circuit applicable to mini-LED display panels.

[0015] The display panel may include a series branch circuit 60 in which a plurality of mini-LEDs are connected in series, and a charge pump module 70 having an output terminal connected to an input terminal of the series branch circuit 60, the charge pump module 70 having a first switching circuit 71 that adjusts the input voltage output by the charge pump module 70 to the series branch circuit 60. Since the series branch circuit 60 is formed by connecting a plurality of mini-LEDs in series, the input voltage flowing through each mini-LED is the same, and the voltage between the terminals of each mini-LED decreases stepwise along the transmission direction of the input voltage. Therefore, the anode voltage of the first mini-LED in the series branch circuit 60, i.e., the input voltage of the series branch circuit 60, i.e., the output voltage of the charge pump module 70, is high, and therefore the power consumption of the charge pump module 70 is high, and thus the power consumption of the display panel is high.

[0016] In order to solve the above problem, referring to FIG. 1, in one embodiment, the charge pump control circuit comprises: a first sampling identification module 10, the sampling terminal of which is connected to the series branch circuit 60, for sampling an input voltage of the series branch circuit 60; and, when it is determined based on the input voltage of the series branch circuit 60 that the series branch circuit 60 is in a heavy load operating state, the first sampling identification module 10 outputs a first switching signal; and, when it is determined based on the input voltage of the series branch circuit 60 that the series branch circuit 60 is in a light load operating state, the first sampling identification module 10 outputs a second switching signal; a PWM module 20, the controlled terminal of which is connected to the output terminal of the first sampling identification module 10, and the output terminal of which is connected to the controlled terminal of the first switching circuit 71, the PWM module 20 outputting a PWM signal to operate the first switching circuit 71 when receiving the first switching signal; a PFM module 30 having a controlled terminal connected to an output terminal of the first sampling identification module 10 and an output terminal connected to a controlled terminal of the first switching circuit 71, the PFM module 30 outputting a PFM signal to operate the first switching circuit 71 when the second switching signal is received.

[0017] In this embodiment, the sampling terminal of the first sampling identification module 10 may be connected to the input terminal of the series branch circuit 60, or may be connected to the output terminal of the charge pump circuit. Because the backlight brightness required for the current screen is different, the working state of each mini-LED can be divided into a heavy load working state and a light load working state. When each mini-LED is in a heavy load working state, the input voltage in the series branch circuit 60 is larger than that of the normal display screen, and when each mini-LED is in a light load working state, the input voltage in the series branch circuit 60 is smaller than that of the normal display screen. Therefore, the first sampling identification module 10 can generate a corresponding first voltage sampling signal FB1 according to the sampling result of the input voltage to determine the current working state of the series branch circuit 60. The first sampling identification module 10 can compare the first voltage sampling signal FB1 with the first predetermined voltage threshold / first predetermined reference voltage Vref1 in real time by executing a corresponding hardware circuit, software program or algorithm. If the voltage sampling signal FB is greater than the first predetermined voltage threshold / first predetermined reference voltage Vref1 as a result of the comparison, it can determine that the series branch circuit 60 is in a heavy load operating state and output a first switching signal. If the first voltage sampling signal FB1 is less than the first predetermined voltage threshold / first reference voltage Vref1 as a result of the comparison, it can determine that the series branch circuit 60 is in a light load operating state and output a second switching signal. Note that the first predetermined voltage threshold / first predetermined reference voltage Vref1 may be set to correspond to the input voltage during normal screen display, and the first switching signal and the second switching signal may be level signals, in which case one of them is a high level signal and the other is a low level signal.

[0018] The PWM (Pulse Width Modulation) module may be configured to operate when the controlled terminal receives a first switching signal, generate a PWM signal with a fixed frequency and an adjustable duty ratio during operation, and not operate when the controlled terminal receives a second switching signal. The PWM module 20 can further communicate with a timing controller in the display device, input a duty ratio setting signal output by the timing controller according to a current display screen during operation, determine a duty ratio parameter of the PWM signal according to the duty ratio setting signal, and control its built-in PWM signal generating unit to output a PWM signal having the corresponding duty ratio parameter to the controlled terminal of the first switching circuit 71, so that the first switching circuit 71 can adjust the output voltage of the charge pump module 70 accordingly, so that the output voltage of the charge pump module 70 can meet the heavy load operating state of the series branch circuit 60.

[0019] The PFM (Pulse Frequency Modulation) module may be configured to operate when the controlled terminal receives a second switching signal, generate a PFM signal with a fixed duty ratio and adjustable frequency during operation, and not operate when the first switching signal is received. The PFM module 30 can store a predetermined frequency parameter in advance, and control its built-in PFM signal generating unit to output a PFM signal having a corresponding frequency parameter to the controlled terminal of the first switching circuit 71 according to the predetermined frequency parameter during operation, so that the first switching circuit 71 can adjust the output voltage of the charge pump module 70 accordingly, so that the output voltage of the charge pump module 70 can meet the light load operation state of the series branch circuit 60. Of course, the PFM module 30 can further communicate with a timing controller in the display device during operation, so that a frequency setting signal output by the timing controller according to the current display screen is input, and the frequency parameter of the PFM signal can be set in real time according to the frequency setting signal.

[0020] In this way, while the display device continues to play images, the first sampling identification module 10 can be switched to operate either the PWM module 20 or the PFM module 30 at any time according to the heavy load operating state or the light load operating state of the series branch circuit 60. By performing PFM control on the first switching circuit 71 in the light load operating state, it is not necessary to operate the first switching circuit 71 under PWM control for a long time, and the conduction loss of the first switching circuit 71 is reduced, so that the operating power consumption of the charge pump module 70 can be reduced, and the problem of high power consumption of the mini-LED display panel can be solved.

[0021] 2 and 3, in one embodiment, the first sampling identification module 10 includes: A first voltage sampling circuit (not shown) whose sampling terminal is connected to the anode of the first mini-LED in the series branch circuit 60, samples the input voltage of the series branch circuit 60, and outputs a first voltage sampling signal FB1; The input terminal of the first comparison circuit 11 is connected to the output terminal of the first voltage sampling circuit, a first predetermined reference voltage Vref1 is input to a second input terminal of the first comparison circuit 11, and the first comparison circuit 11 outputs the first switching signal or the second switching signal depending on a comparison result between the first voltage sampling signal FB1 and the first reference voltage Vref1.

[0022] The first voltage sampling circuit may be realized by using a shunt circuit or a voltage divider circuit made of a resistive element, or may use a dedicated voltage detection element, and is not limited in this specification. The first voltage sampling circuit can use the principle of resistive voltage division or resistive shunting to sample the anode voltage of the first mini-LED in the series branch circuit 60, and output a first voltage detection signal in a voltage form or a current form.

[0023] The comparison circuit 12 may be realized using a comparison circuit 12 consisting of an operational amplifier, or may be realized using a dedicated comparison chip. The comparison circuit 12 compares the first voltage sampling signal FB1 inputted to the first input terminal and the second input terminal, respectively, with the first predetermined reference voltage Vref1 in real time, and if the comparison result shows that the first voltage sampling signal FB1 is greater than the first reference voltage Vref1, it determines that the series branch circuit 60 is in a heavy load operating state and outputs a first switching signal, and if the comparison result shows that the first voltage sampling signal FB1 is less than the first reference voltage Vref1, it determines that the series branch circuit 60 is in a light load operating state and outputs a second switching signal. Note that if the comparison result shows that the voltage sampling signal FB is equal to the first reference voltage Vref1, the comparison circuit 12 maintains the first switching signal or the second switching signal currently being outputted.

[0024] In the embodiment shown in Figures 2 and 3, the first comparison circuit 11 includes a first operational amplifier U1, the first operational amplifier U1 has a non-inverting input terminal to which the first voltage sampling signal FB1 is input, an inverting input terminal to which the first reference voltage Vref1 is input, and an output terminal to which the controlled terminal of the PWM module 20 and the controlled terminal of the PFM module 30 are respectively connected. In other words, the first switching signal is a high level signal, and the second switching signal is a low level signal. According to this embodiment, the comparison circuit 12 is realized in a completely hardware circuit manner, which can avoid the situation where software failure affects the comparison result, and is easy to improve the stability of the control, and the hardware circuit has a fast response speed and is more suitable for the control requirements of a high refresh rate.

[0025] 2 and 3, in one embodiment, the PFM identification module 30 includes: a phase inversion module 31 whose input terminal is connected to the output terminal of the first sampling identification module 10 and which performs phase inversion processing on the second switching signal and outputs the result; a flip-flop module 32 having a first input terminal connected to the output terminal of the inversion module 31, a second input terminal connected to the output terminal of the first sampling identification module 10, and an output terminal which is the output terminal of the PFM module 30, for generating and outputting a corresponding PFM signal based on the second switching signal after phase inversion processing received from the first input terminal when the second switching signal is received from the second input terminal.

[0026] In this embodiment, the phase inversion module 31 may be realized by using at least one phase inverter. When the inversion module 31 receives a high-level signal represented as "1", it can invert the phase of the signal to a low-level signal represented as "0" and output it, and when the inversion module 31 receives a low-level signal represented as "0", it can invert the phase of the signal to a high-level signal represented as "1" and output it.

[0027] The first input terminal of the flip-flop module 32 is interconnected with the input terminal of the phase inversion module 31 to form the controlled terminal of the PFM module 30. Thus, when the second switching signal is input to the phase inversion module 31, the level signals received from the first input terminal and the second input terminal of the flip-flop module 32 are inverse, and in this case, the flip-flop module 32 can output a PFM signal with the same level as the level signal received from the first input terminal. In the embodiment shown in FIG. 2 and FIG. 3, the flip-flop module 32 can be realized using an RS flip-flop U3. The RS flip-flop U3 can have a CLK input terminal, an S input terminal, an R input terminal, a Q output terminal and a Q non-output terminal. Here, the S input terminal can be the first input terminal of the flip-flop module 32, the R input terminal can be the second input terminal of the flip-flop module 32, and the Q output terminal can be the output terminal of the flip-flop module. Thus, when a second switching signal is received from the input terminal of the phase inversion module 31, the R input terminal of the RS flip-flop U3 is set to "0" and the S input terminal is set to "1", outputting a high-level signal indicated as "1" from the Q output terminal; and when a first switching signal is received from the input terminal of the phase inversion module 31, the R input terminal of the RS flip-flop U3 is set to "1" and the S input terminal is set to "0", outputting a low-level signal indicated as "0" from the Q output terminal.

[0028] 2 and 3, in one embodiment, the charge pump control circuit includes: The amplifier module 40 further includes an amplifier having a controlled terminal connected to the output terminal of the PFM module 30, an input terminal to which a gate-on voltage is input, and an output terminal connected to the controlled terminal of the first switching circuit 71, which amplifies the PFM signal according to the gate-on voltage and then outputs it to the controlled terminal of the first switching circuit 71.

[0029] Since the output voltage amplitude of the flip-flop module 32 is small, the driving ability for the first switching circuit 71 is weak. To address this problem, according to the technical solution of the present application, an amplifier module 40 is further provided, which can be realized by an amplifier circuit made of a switching element, and the input terminal of the amplifier module 40 can be connected to the gate on / off voltage output terminal of the power management circuit in the display device. When the amplifier module 40 receives a PFM signal, it controls the on or off of the corresponding switching element according to the PFM signal, so that the gate on voltage can be input to the on switching element, and outputs it to the controlled terminal of the first switching circuit 71 as a high-level signal in the amplified PWM signal, thereby realizing signal amplification of the PFM signal. By configuring in this way, it is easy to strengthen the driving ability of the PFM signal for the first switching circuit 71. In addition, since the gate-on voltage VGH can usually reach up to 30V, it can perfectly meet the driving requirements for the first switching circuit 71, and it is not necessary to provide a dedicated voltage generating circuit for the technical solution of the present application, so that the area occupied by the charge pump control circuit of the present application on the circuit board can be reduced, which is advantageous for the narrow frame design of the display device. In addition, the high voltage value of the gate-on voltage VGH is also advantageous for further reducing the conduction loss of the first switching circuit 71.

[0030] In one embodiment, the amplification module 40 includes a first N-type thin film transistor T1 and a first P-type thin film transistor T2; The input terminal of the first N-type thin film transistor T1 is the input terminal of the amplification module 40, the controlled terminal of the first N-type thin film transistor T1 and the controlled terminal of the first P-type thin film transistor T2 are interconnected to form a controlled terminal of the amplification module 40, the output terminal of the first N-type thin film transistor T1 and the input terminal of the first P-type thin film transistor T2 are interconnected to form an output terminal of the amplification module 40, and the output terminal of the first P-type thin film transistor T2 is grounded.

[0031] In this embodiment, the first N-type thin film transistor T1 and the first P-type thin film transistor T2 constitute a push-pull amplifier circuit. Thus, when the flip-flop module 32 outputs a high-level signal, the first N-type thin film transistor T1 is turned on and the first P-type thin film transistor T2 is turned off, so that a gate-on signal is input and output as an amplified PFM signal; when the flip-flop module 32 outputs a low-level signal, the first N-type thin film transistor T1 is turned off and the first P-type thin film transistor T2 is turned on, so that the amplification module 40 outputs a low-level signal. With this configuration, the amplification module 40 can amplify the signal amplitude of the high-level signal in the PFM signal using only the gate-on voltage without affecting the frequency and period of the PFM signal. In addition, only one of the first N-type thin film transistor T1 and the first P-type thin film transistor T2 is turned on each time, so that the conduction loss is small and the efficiency is high, and the driving ability and switching speed of the first switching circuit 71 can be improved while reducing its own loss.

[0032] 3, in one embodiment, the charge pump control circuit further includes a second sampling identification module 50, the first input terminal of which is connected to the output terminal of the PWM module 20, the second output terminal of which is connected to the output terminal of the PFM module 30, the sampling terminal of which is connected to the series branch circuit 60, and the first output terminal and the second output terminal of which are respectively connected to the controlled terminal of the first switching circuit 71, the second sampling identification module 50 sampling the output voltage of the series branch circuit 60, and when it is determined according to the output voltage of the series branch circuit 60 that the series branch circuit 60 is in a heavy load operating state, the second sampling identification module 50 outputs the input PWM signal from the first output terminal to the controlled terminal of the first switching circuit 71, and when it is determined according to the output voltage of the series branch circuit 60 that the series branch circuit 60 is in a light load operating state, the second sampling identification module 50 outputs the input PFM signal from the second output terminal to the controlled terminal of the first switching circuit 71.

[0033] A single input voltage cannot accurately represent the load operating state of the series branch circuit 60. For example, the series branch circuit 60 may be in a heavy load operating state but the input voltage is small, or in a light load operating state but the input voltage is large. To address this problem, the present application provides a second path sampling identification module, i.e., a second sampling identification module 50. The second sampling identification module 50 may have a sampling terminal connected to the input terminal of the series branch circuit 60 to sample the output voltage of the series branch circuit 60. Note that, when the series branch circuit 60 is in a heavy load operating state, the output voltage is larger than that of a normal display screen, and when the series branch circuit 60 is in a light load operating state, the output voltage is smaller than that of a normal display screen. Therefore, the second sampling identification module 50 can generate a corresponding second voltage sampling signal FB2 according to the sampling result of the output voltage to determine the current operating state of the series branch circuit 60.

[0034] The second sampling identification module 50 can compare the second voltage sampling signal FB2 with the second predetermined voltage threshold / second predetermined reference voltage Vref2 in real time by executing a corresponding hardware circuit, software program or algorithm. If the comparison result shows that the second voltage sampling signal FB2 is greater than the second predetermined voltage threshold / second predetermined reference voltage Vref2, it can be determined that the series branch circuit 60 is in a heavy load operating state, and in this case, the second sampling identification module 50 can output the PWM signal output by the PWM module 20 to the first switching circuit 71 to realize PWM control for the first switching circuit 71. Thus, when the series branch circuit 60 is in a heavy load operating state and the input voltage is small, the PWM module 20 can normally perform PWM control for the first switching control circuit to meet the demand of the heavy load operating state of the series branch circuit 60. If the comparison result shows that the second voltage sampling signal FB2 is smaller than the second predetermined voltage threshold / second reference voltage Vref2, it can be determined that the series branch circuit 60 is in a light-load operating state. In this case, the second sampling identification module 50 can realize PFM control for the first switching circuit 71 by outputting the PFM signal output by the PFM module 30 to the first switching circuit 71. As a result, when the series branch circuit 60 is in a light-load operating state and the input voltage is large, the PFM module 30 can normally perform PFM control for the first switching control circuit to meet the demand of the light-load operating state of the series branch circuit 60. Note that the second predetermined voltage threshold / second predetermined reference voltage Vref2 may be set to correspond to the output voltage during normal screen display. By configuring in this way, the control of the first switching circuit in the present application can be further adapted to the load situation of the series branch circuit 60, and the stability of the control can be easily improved.

[0035] Referring to FIG. 3, in one embodiment, the second sampling identification module 50 includes: A second voltage sampling circuit (not shown) whose sampling terminal is connected to the cathode of the last mini-LED in the series branch circuit 60, samples the output voltage of the series branch circuit 60, and outputs a second voltage sampling signal FB2; a second comparison circuit 51 having a first input terminal connected to an output terminal of the second voltage sampling circuit, a second predetermined reference voltage Vref2 input to a second input terminal, and outputting a first switching control signal when it is determined that the series branch circuit 60 is in a heavy load operation state according to a comparison result between the second voltage sampling signal FB2 and the second predetermined reference voltage Vref2, and outputting a second switching control signal when it is determined that the series branch circuit 60 is in a light load operation state; a second switching circuit 52, the first input terminal, the second input terminal, the first output terminal and the second output terminal of which are respectively the first input terminal, the second input terminal, the first output terminal and the second output terminal of the second sampling identification module 50, and the controlled terminal of which is connected to the output terminal of the second comparison circuit 51, the second switching circuit 52 outputting the input PWM signal from the first output terminal when receiving the first switching control signal, and outputting the input PFM signal from the first output terminal when receiving the second switching control signal.

[0036] The implementation method of the second voltage sampling circuit can be referred to the first voltage sampling circuit, and is not described here. The second voltage sampling circuit can use the principle of resistive voltage division or resistive current division to sample the anode voltage of the last mini-LED in the series branch circuit 60, and output a second voltage detection signal in voltage or current form.

[0037] The implementation method of the second comparison circuit 51 can refer to the first comparison circuit 11, and the description is omitted here. The second comparison circuit 51 compares the second voltage sampling signal FB2 inputted to the first input terminal and the second input terminal respectively with the second predetermined reference voltage Vref2 in real time, and if the second voltage sampling signal FB2 is greater than the second reference voltage Vref2 as a result of the comparison, it determines that the series branch circuit 60 is in a heavy load operation state and outputs a first switching control signal, and if the second voltage sampling signal FB2 is less than the second reference voltage Vref2 as a result of the comparison, it determines that the series branch circuit 60 is in a light load operation state and outputs a second switching control signal. Note that if the second voltage sampling signal FB2 is equal to the second reference voltage Vref2 as a result of the comparison, the second comparison circuit 5112 maintains the first switching control signal or the second switching control signal currently being outputted. One of the first switching control signal and the second switching control signal may be a high level signal, and the other may be a low level signal. In the embodiment shown in FIG. 3, the second comparison circuit 51 includes a second operational amplifier U2, the second operational amplifier U2 has an inverting input terminal to which the second voltage sampling signal FB2 is input, and a non-inverting input terminal to which the second predetermined reference voltage Vref2 is input. In other words, the first switching control signal is a low level signal, and the second switching control signal is a high level signal. According to this embodiment, the comparison circuit 12 is realized by adopting a complete hardware circuit, which is advantageous in improving the stability of control and the adaptability to a high refresh rate.

[0038] The second switching circuit 52 can be realized by a plurality of switching elements. When the second switching circuit 52 receives a first switching control signal, it controls the on / off of its corresponding switching element to connect the first input terminal and the first output terminal and to disconnect the second input terminal and the second output terminal, thereby realizing the input / output of the PWM signal, and when the second switching control signal is received, it controls the on / off of its corresponding switching element to disconnect the first input terminal and the first output terminal and to communicate the second input terminal and the second output terminal, thereby realizing the input / output of the PWM signal.

[0039] In one embodiment, the second switching circuit 52 includes a second N-type thin film transistor T3 and a second P-type thin film transistor T4; The controlled terminal of the second N-type thin film transistor T3 and the controlled terminal of the second P-type thin film transistor T4 are interconnected to constitute a controlled terminal of the second switching circuit 52, the input terminal of the second P-type thin film transistor T4 is a first input terminal of the second switching circuit 52, the output terminal of the second P-type thin film transistor T4 is a first output terminal of the second switching circuit 52, the input terminal of the second N-type thin film transistor T3 is a second input terminal of the second switching circuit 52, and the output terminal of the second N-type thin film transistor T3 is a second output terminal of the second switching circuit 52.

[0040] When the controlled terminal of the second switching circuit 52 receives a first switching control signal which is a low level signal, the second P-type thin film transistor T4 is turned on and the second N-type thin film transistor T3 is turned off, thereby connecting the first input terminal and the first output terminal of the second switching circuit 52 and simultaneously disconnecting the connection between the second input terminal and the second output terminal. When the controlled terminal of the second switching circuit 52 receives a second switching control signal which is a high level signal, the second P-type thin film transistor T4 is turned off and the second N-type thin film transistor T3 is turned on, thereby connecting the second input terminal and the second output terminal of the second switching circuit 52 and simultaneously disconnecting the connection between the first input terminal and the first output terminal. Second Example

[0041] 4, the present application further proposes a display panel including a serial branch circuit 60, a charge pump module 70 and a charge pump control circuit. The specific structure of the charge pump control circuit can be referred to the above embodiments. The display panel adopts all the technical solutions of all the above embodiments, and thus has at least all the beneficial effects brought by the technical solutions of the above embodiments, and thus the description is omitted here.

[0042] Here, the series branch circuit 60 may include a plurality of mini-LEDs arranged in series, and the number of mini-LEDs is determined according to actual needs and is not limited here. The charge pump module 70 has a first switching circuit 71, the output terminal of the charge pump module 70 is connected to the input terminal of the series branch circuit 60, and the first switching circuit 71 adjusts the output voltage output from the charge pump module 70 to the series branch circuit during operation. A charge pump control circuit is respectively connected to the series branch circuit 60 and the first switching circuit 71.

[0043] In the embodiment shown in FIG. 4, the first switching circuit 71 includes a first switching element Q1, and the charge pump module 70 further includes an input capacitance Ci, a first inductance L1, a first diode D1, and an output capacitance Co. The input capacitance Ci has a first terminal connected to the first terminal of the first inductance L1, and is also an input terminal of the charge pump circuit, to which an input voltage is input. The first inductance L1 has a second terminal connected to the input terminal of the first switching element Q1 and the anode of the first diode D1. The first diode D1 has a cathode connected to the first terminal of the output capacitance Co, and is also an output terminal of the charge pump circuit, to which an output voltage is output to the series branch circuit 60. The second terminal of the input capacitance Ci, the output terminal of the first switching element Q1, and the second terminal of the output capacitance Co are connected to each other and grounded. The first switching element Q1 controls the charge and discharge states of the input capacitance Ci, the first inductance L1, and the output capacitance Co under the control of the charge pump control circuit, thereby boosting or lowering the input voltage and outputting it as an output voltage to the series branch circuit 60. In this embodiment, the series branch circuit 60 further includes a first resistor R1 that can be connected between the cathode of the last mini-LED and ground.

[0044] The present application further proposes a display device including a display panel. The specific structure of the display panel can be referred to the above embodiments. The display device adopts all the technical solutions of all the above embodiments, and therefore has at least all the beneficial effects brought by the technical solutions of the above embodiments, and thus the description is omitted here.

[0045] The above is merely a preferred embodiment of the present application, and does not limit the scope of the patent of the present application. Under the application concept of the present application, the equivalent structural transformation made by using the contents of the specification and the attached drawings of the present application, or the direct / indirect application to other related technical fields, are all included in the scope of protection of the patent of the present application.

Claims

1. A charge pump control circuit applied to a display panel, A first sampling identification module (10), a PWM module (20), and a PFM module (30), The display panel includes: A series branch circuit (60) including a plurality of mini-LEDs arranged in series connection; a charge pump module (70) having an output terminal connected to the input terminal of the series branch circuit (60) and a first switching circuit (71) for regulating an output voltage; the first sampling identification module (10) has a sampling terminal connected to the series branch circuit (60), samples an input voltage of the series branch circuit (60), and outputs a first switching signal when it is determined that the series branch circuit (60) is in a heavy load operating state based on the input voltage of the series branch circuit (60), and outputs a second switching signal when it is determined that the series branch circuit (60) is in a light load operating state based on the input voltage of the series branch circuit (60); The PWM module (20) has a controlled terminal connected to the output terminal of the first sampling identification module (10) and an output terminal connected to the controlled terminal of the first switching circuit (71). When the PWM module (20) receives the first switching signal, the PWM module (20) outputs a PWM signal to operate the first switching circuit (71); the PFM module (30) has a controlled terminal connected to the output terminal of the first sampling identification module (10) and an output terminal connected to the controlled terminal of the first switching circuit (71); when receiving the second switching signal, the PFM module (30) outputs a PFM signal to operate the first switching circuit (71); The PFM module (30) comprises: a phase inversion module (31) whose input terminal is connected to the output terminal of the first sampling identification module (10) and which performs phase inversion processing on the second switching signal and outputs the result; a flip-flop module (32) having a first input terminal connected to the output terminal of the phase inversion module (31), a second input terminal connected to the output terminal of the first sampling identification module (10), and an output terminal which is the output terminal of the PFM module (30), and which generates and outputs a corresponding PFM signal based on the second switching signal after phase inversion processing received from the first input terminal when the second switching signal is received from the second input terminal.

2. The first sampling identification module (10) comprises: a first voltage sampling circuit having a sampling terminal connected to the anode of a first mini-LED in the series branch circuit (60), sampling an input voltage of the series branch circuit (60) and outputting a first voltage sampling signal (FB1); a first comparison circuit (11) having a first input terminal connected to an output terminal of the first voltage sampling circuit, a second input terminal to which a first predetermined reference voltage (Vref1) is input, and outputting the first switching signal or the second switching signal according to a comparison result between the first voltage sampling signal (FB1) and the first predetermined reference voltage (Vref1); 2. The charge pump control circuit of claim 1, comprising:

3. The amplifier module (40) has a controlled terminal connected to the output terminal of the PFM module (30), an input terminal to which a gate-on voltage (VGH) is input, and an output terminal connected to the controlled terminal of the first switching circuit (71), and amplifies the PFM signal according to the gate-on voltage (VGH) before outputting it to the controlled terminal of the first switching circuit (71).

2. The charge pump control circuit of claim 1.

4. The amplification module (40) includes a first N-type thin film transistor (T1) and a first P-type thin film transistor (T2); The input terminal of the first N-type thin film transistor (T1) is an input terminal of the amplification module (40), the controlled terminal of the first N-type thin film transistor (T1) and the controlled terminal of the first P-type thin film transistor (T2) are interconnected to form a controlled terminal of the amplification module (40), the output terminal of the first N-type thin film transistor (T1) and the input terminal of the first P-type thin film transistor (T2) are interconnected to form an output terminal of the amplification module (40), and the output terminal of the first P-type thin film transistor (T2) is grounded.

4. The charge pump control circuit of claim 3.

5. a second sampling identification module (50) having a first input terminal connected to an output terminal of the PWM module (20), a second output terminal connected to an output terminal of the PFM module (30), a sampling terminal connected to the series branch circuit (60), and a first output terminal and a second output terminal respectively connected to a controlled terminal of the first switching circuit (71), the second sampling identification module (50) sampling an output voltage of the series branch circuit (60), and outputting the input PWM signal from the first output terminal to the controlled terminal of the first switching circuit (71) when it is determined that the series branch circuit (60) is in a heavy load operating state based on the output voltage of the series branch circuit (60), and outputting the input PFM signal from the second output terminal to the controlled terminal of the first switching circuit (71) when it is determined that the series branch circuit (60) is in a light load operating state based on the output voltage of the series branch circuit (60). The charge pump control circuit of claim 1 further comprising:

6. The second sampling identification module (50) a second voltage sampling circuit (51) having a sampling terminal connected to the cathode of the last mini-LED in the series branch circuit (60) and sampling an output voltage of the series branch circuit (60) to output a second voltage sampling signal (FB2); a second comparison circuit (52) having a first input terminal connected to an output terminal of the second voltage sampling circuit, a second predetermined reference voltage (Vref2) input to a second input terminal, and outputting a first switching control signal when it is determined that the series branch circuit (60) is in a heavy load operating state according to a comparison result between the second voltage sampling signal (FB2) and the second predetermined reference voltage (Vref2), and outputting a second switching control signal when it is determined that the series branch circuit (60) is in a light load operating state; a second switching circuit (53) whose first input terminal, second input terminal, first output terminal and second output terminal are respectively the first input terminal, second input terminal, first output terminal and second output terminal of the second sampling identification module (50), and whose controlled terminal is connected to the output terminal of the second comparison circuit (52), wherein the second switching circuit (53) outputs the input PWM signal from the first output terminal when receiving the first switching control signal, and outputs the input PFM signal from the first output terminal when receiving the second switching control signal; 6. The charge pump control circuit of claim 5, comprising:

7. The second switching circuit (53) includes a second N-type thin film transistor (T3) and a second P-type thin film transistor (T4); The controlled terminal of the second N-type thin film transistor (T3) and the controlled terminal of the second P-type thin film transistor (T4) are interconnected to form a controlled terminal of the second switching circuit (53), the input terminal of the second P-type thin film transistor (T4) is a first input terminal of the second switching circuit (53), the output terminal of the second P-type thin film transistor (T4) is a first output terminal of the second switching circuit (53), the input terminal of the second N-type thin film transistor (T3) is a second input terminal of the second switching circuit (53), and the output terminal of the second N-type thin film transistor (T3) is a second output terminal of the second switching circuit (53).

7. The charge pump control circuit of claim 6.

8. The PWM module operates when a controlled terminal receives a first switching signal, and generates a PWM signal having a fixed frequency and an adjustable duty ratio during operation; Configurable to be inoperative when a second switching signal is received 2. The charge pump control circuit of claim 1.

9. The PWM module (20) can further communicate with a timing controller in a display device to receive a duty ratio setting signal output by the timing controller according to a current display screen during operation, determine a duty ratio parameter of a PWM signal according to the duty ratio setting signal, and control its built-in PWM signal generating unit to output a PWM signal having the corresponding duty ratio parameter to a controlled terminal of a first switching circuit (71), thereby enabling the first switching circuit (71) to adjust the output voltage of the charge pump module (70) accordingly.

9. The charge pump control circuit of claim 8.

10. The PFM module (30) operates when the controlled terminal receives a second switching signal, and generates a PFM signal having a fixed duty ratio and an adjustable frequency during operation; Configurable to be inoperative upon receiving a first switching signal 2. The charge pump control circuit of claim 1.

11. The PFM module (30) can pre-store a predetermined frequency parameter, and control its built-in PFM signal generating unit to output a PFM signal having a corresponding frequency parameter to a controlled terminal of a first switching circuit (71) according to the predetermined frequency parameter during operation, so that the first switching circuit (71) can adjust the output voltage of the charge pump module (70) accordingly.

11. The charge pump control circuit of claim 10.

12. The PFM module (30) further communicates with a timing controller in a display device during operation, so that a frequency setting signal output by the timing controller according to a current display screen is input, and the frequency parameters of the PFM signal can be set in real time according to the frequency setting signal.

11. The charge pump control circuit of claim 10.

13. A display panel, A series branch circuit (60) including a plurality of mini-LEDs arranged in series connection; a charge pump module (70) having an output terminal connected to the input terminal of the series branch circuit (60) and a first switching circuit (71) for adjusting an output voltage; A charge pump control circuit according to any one of claims 1 to 12, connected to the series branch circuit (60) and to the first switching circuit (71), respectively; A display panel including:

14. The charge pump control circuit includes: a first sampling identification module (10) having a sampling terminal connected to the series branch circuit (60), sampling an input voltage of the series branch circuit (60), and outputting a first switching signal when it is determined that the series branch circuit (60) is in a heavy load operating state based on the input voltage of the series branch circuit (60), and outputting a second switching signal when it is determined that the series branch circuit (60) is in a light load operating state based on the input voltage of the series branch circuit (60); a PWM module (20) having a controlled terminal connected to an output terminal of the first sampling identification module (10) and an output terminal connected to a controlled terminal of the first switching circuit (71), the PWM module (20) outputting a PWM signal to operate the first switching circuit (71) when the first switching signal is received; a PFM module (30) having a controlled terminal connected to an output terminal of the first sampling identification module (10) and an output terminal connected to a controlled terminal of the first switching circuit (71), the PFM module (30) outputting a PFM signal to operate the first switching circuit (71) when the second switching signal is received; The display panel of claim 13 .

15. A display device including a display panel, The display panel includes: A series branch circuit (60) including a plurality of mini-LEDs arranged in series connection; a charge pump module (70) having an output terminal connected to the input terminal of the series branch circuit (60) and a first switching circuit (71) for adjusting an output voltage; A charge pump control circuit according to any one of claims 1 to 12, connected to the series branch circuit (60) and to the first switching circuit (71), respectively; A display device comprising:

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