Backlight control circuit, method and terminal device

Abstract

The present application provides a backlight control circuit, method and terminal device, including: a charging circuit, a first switch circuit, a first adjustment circuit and a processor; the charging circuit is used to receive a first voltage input by a power supply, and input a second voltage obtained by conversion processing to a battery; the charging circuit is also used to input a preset voltage to the first switch circuit through a preset terminal, and the preset voltage is a voltage that has not been adjusted by the second adjustment circuit of the charging circuit; the processor is used to control the first switch circuit to be turned on when a voltage is detected at the input terminal of the charging circuit; the first adjustment circuit is used to adjust the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and input the conditioned third voltage to the backlight module, so as to control the display brightness of the backlight module through the third voltage, thereby improving the conversion efficiency of the mobile phone backlight power supply.

Description

Technical Field

[0001] The present application relates to the technical field of terminal equipment, and in particular to a backlight control circuit, method and terminal equipment. Background Art

[0002] With the continuous development of mobile terminals such as smart phones and tablet computers, users may use the mobile terminal to handle other services during the charging process of the mobile terminal. Taking a mobile phone as an example, when the mobile phone is charging and playing a video at the same time, the power consumption of its display screen accounts for more than 60% of the total power consumption of the mobile phone system, and 90% of the power consumption of the display screen is mainly used for backlight display, which causes the mobile phone to charge slowly. For example, the display screen can be a liquid crystal display (LCD), an organic light-emitting diode (OLED) display screen, or other types of display screens.

[0003] In order to improve the charging efficiency of mobile phones, in the prior art, the conversion efficiency of the backlight power supply is usually improved to achieve the purpose of improving the charging efficiency of mobile phones. When improving the conversion efficiency of the backlight power supply, it is achieved by replacing a high-efficiency backlight integrated circuit (IC), but the price of a high-efficiency backlight IC is high, which will increase the cost of the mobile phone, thereby resulting in a higher cost of the mobile phone.

[0004] Therefore, how to improve the conversion efficiency of the backlight power supply of the mobile phone while the mobile phone is being charged and used is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] The present application provides a backlight control circuit, method and terminal device to improve the conversion efficiency of the backlight power supply of the terminal device.

[0006] In a first aspect, an embodiment of the present application provides a backlight control circuit, which may include:

[0007] A charging circuit, a first switch circuit, a first adjustment circuit and a processor; wherein the charging circuit includes a second adjustment circuit;

[0008] The input end of the charging circuit is connected to the output end of the power supply, the input / output end of the charging circuit is connected to the battery, the preset end of the charging circuit is connected to the first end of the first switch circuit, the second end of the first switch circuit is connected to the processor, the third end of the first switch circuit is connected to the input end of the first adjustment circuit, and the output end of the first adjustment circuit is connected to the backlight module of the terminal device;

[0009] The charging circuit is used to receive a first voltage inputted from a power source, and convert the first voltage obtained by the conversion process to input a second voltage to the battery;

[0010] The charging circuit is further used to input a preset voltage to the first switch circuit through a preset terminal, where the preset voltage is a voltage that has not been adjusted by the second adjustment circuit of the charging circuit;

[0011] The processor is used to control the first switch circuit to conduct when detecting that there is a voltage at the input end of the charging circuit;

[0012] The first adjustment circuit is used for adjusting the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and inputting the conditioned third voltage to the backlight module to control the display brightness of the backlight module through the third voltage.

[0013] It can be seen that, in the backlight control circuit provided in the embodiment of the present application, when the power supply provides voltage to the charging circuit, the first voltage at the input end of the charging circuit is first limited by the first current limiting circuit, and a part of the voltage after the current limiting is input to the battery through the second MOS tube, so as to realize charging the battery. In addition, another part of the voltage after the current limiting is input to the first switch circuit through the first MOS tube through the first output end between the first MOS tube and the second adjustment circuit. When the processor detects that there is voltage at the input end of the charging circuit, it controls the first switch circuit to be turned on, so that the first adjustment circuit adjusts the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and inputs the conditioned third voltage to the backlight module, so as to control the display brightness of the backlight module through the third voltage, thereby realizing providing the required voltage for the backlight module. In this way, when the terminal device is charged and used, in the process from the first voltage output by the power supply to the required third voltage provided for the backlight module, the first voltage only undergoes one power conversion of the first adjustment circuit, thereby improving the conversion efficiency of the mobile phone backlight power supply.

[0014] In a possible implementation, the charging circuit further includes a first current limiting circuit, a first MOS transistor, a control subcircuit and a second MOS transistor;

[0015] Among them, the input end of the first current limiting circuit is connected to the output end of the power supply, the output end of the first current limiting circuit is respectively connected to the first end of the first MOS tube and the first end of the control subcircuit, the second end of the MOS tube is connected to the first end of the second adjustment circuit, the second end of the second adjustment circuit is respectively connected to the second end of the control submodule and the first end of the second MOS tube, and the second end of the second MOS tube is connected to the battery.

[0016] In a possible implementation, the preset end is the first output end of the charging circuit, and the second end of the MOS tube and the first end of the second adjustment circuit are respectively connected to the first switch circuit through the first output end.

[0017] In a possible implementation manner, the preset end is an input end of the charging circuit.

[0018] In a possible implementation, the backlight control circuit may further include a second current limiting circuit;

[0019] Wherein, the input end of the second current limiting circuit is connected to the input end of the charging circuit, and the output end of the second current limiting circuit is connected to the first end of the first switch circuit;

[0020] The second current limiting circuit is used to receive a first voltage input by a power supply, and perform current limiting processing on the first voltage to obtain a preset voltage, thereby preventing the charger from burning out due to excessive current, and achieving current limiting control of the preset voltage.

[0021] In a possible implementation, the first switch circuit is a switch circuit with a current limiting control function;

[0022] The first switch circuit is further used to detect a preset voltage at the first end of the first switch circuit, and send a closing request signal to the processor if the preset voltage at the first end of the first switch circuit is less than a preset threshold;

[0023] The processor is further configured to control the first switch circuit to conduct according to the closing request signal.

[0024] In a possible implementation, the first switch circuit is further configured to send an interrupt request signal to the processor if a preset voltage at the first end of the first switch circuit is greater than a preset threshold;

[0025] The processor is further configured to control the first switch circuit to be disconnected according to the interrupt request signal until the processor does not receive the interrupt request signal.

[0026] In a possible implementation, the first switch circuit is further configured to send an interrupt request signal to the processor if a preset voltage at the first end of the first switch circuit is greater than a preset threshold;

[0027] The processor is also used to control the reduction of the brightness of the backlight module according to the interrupt request signal until the processor does not receive the interrupt request signal.

[0028] In a possible implementation, the backlight control circuit may further include a second switch circuit and a switch control circuit;

[0029] Wherein, the first end of the second switch circuit is connected to the second output end of the charging circuit, the second end of the second switch circuit is connected to the processor, and the third end of the second switch circuit is connected to the input end of the first adjustment circuit; the input end of the switch control circuit is connected to the processor, and the output end of the switch control circuit is connected to the third end of the first switch circuit;

[0030] The processor is also used to control the second switch circuit to be turned on and control the first switch circuit to be disconnected through the switch control circuit when it is detected that there is no voltage at the input end of the charging circuit and there is voltage in the charging circuit, so as to avoid the occurrence of erroneous switching, so that when the input end of the terminal device is not connected to the power supply but there is voltage in the charging circuit of the terminal device, the first switch circuit can be controlled to be disconnected and the second switch circuit can be controlled to be turned on through the switch control circuit, so that when the second switch circuit is turned on, the required voltage is input to the backlight module through the first adjustment circuit, and the display brightness of the backlight module is controlled by the input voltage, so as to provide the required voltage to the backlight module while charging to control the display brightness of the backlight module.

[0031] In a possible implementation, the switch control circuit may include a first resistor, a second resistor, and a diode;

[0032] One end of the first resistor is connected to the output end of the diode, one end of the second resistor is connected to the input end of the diode, the other end of the second resistor is connected to the processor, and the input end of the diode is also connected to the third end of the first switch circuit.

[0033] In a possible implementation, the second current limiting circuit may include an overcurrent detection circuit, an overtemperature detection circuit, an AND gate, and an abnormal state output circuit;

[0034] Among them, the first end of the overcurrent detection circuit and the first end of the overtemperature detection circuit are both connected to the input end of the charging circuit, the second end of the overcurrent detection circuit is connected to the first end of the AND gate, the second end of the overtemperature detection circuit is connected to the second end of the AND gate, the third end of the AND gate is connected to the first end of the abnormal state output circuit, and the second end of the abnormal state output circuit is connected to the first end of the first switch circuit.

[0035] In a possible implementation, when the second regulating circuit is a step-down circuit, the first regulating circuit is a step-up circuit; or, when the second regulating circuit is a step-up circuit, the first regulating circuit is a step-down circuit.

[0036] In a possible implementation manner, the first output end is any one of a power midpoint PMID, a midpoint MID, a USB midpoint USB_MID, a charging power midpoint CHG_VMID, and a power midpoint VMID.

[0037] In a possible implementation manner, the second switch circuit is a switch circuit with a current limiting control function.

[0038] In a possible implementation manner, the first switch circuit is any one of a MOS tube, a triode, a transistor and a load switch.

[0039] In a second aspect, an embodiment of the present application further provides a backlight control method, which is applied to a backlight control circuit, wherein the backlight control circuit includes a charging circuit, a first switch circuit, a first adjustment circuit, and a processor, wherein the charging circuit includes a second adjustment circuit. The backlight control method may include:

[0040] The charging circuit receives a first voltage inputted from a power source, converts the first voltage into a second voltage and inputs it into the battery;

[0041] The charging circuit inputs a preset voltage to the first switch circuit through a preset terminal of the charging circuit, where the preset voltage is a voltage that has not been adjusted by the second adjustment circuit of the charging circuit;

[0042] When the processor detects that there is a voltage at the input end of the charging circuit, the processor controls the first switch circuit to be turned on;

[0043] When the first switch circuit is turned on, the first adjustment circuit adjusts the preset voltage according to the voltage of the backlight module, and inputs the conditioned third voltage to the backlight module to control the display brightness of the backlight module through the third voltage.

[0044] In a possible implementation, the preset end is a first output end of a charging circuit, the charging circuit includes a first current limiting circuit, and the charging circuit inputs a preset voltage to the first switch circuit through the preset end of the charging circuit, which may include:

[0045] The first current limiting circuit performs current limiting processing on the first preset voltage to obtain a preset voltage, and inputs the preset voltage to the first switch circuit through the first output terminal.

[0046] In a possible implementation, the preset end is an input end of the charging circuit, and the charging circuit inputs a preset voltage to the first switch circuit through the preset end of the charging circuit, which may include:

[0047] The charging circuit inputs a preset voltage to the first switch circuit through an input terminal of the charging circuit.

[0048] In a possible implementation, the backlight control circuit includes a second current limiting circuit, and the first adjustment circuit adjusts the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and before the conditioned third voltage is input to the backlight module, it may also include:

[0049] The second current limiting circuit receives a first voltage input from a power supply, and performs current limiting processing on the first voltage to obtain a preset voltage.

[0050] In a possible implementation, the first switch circuit is a switch circuit with a current limiting control function, and the first adjustment circuit adjusts the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and before the conditioned third voltage is input to the backlight module, it may also include:

[0051] The first switch circuit detects a preset voltage at a first end of the first switch circuit, and sends a closing request signal to the processor if the preset voltage at the first end of the first switch circuit is less than a preset threshold;

[0052] The processor also controls the first switch circuit to conduct according to the closing request signal, so as to input a preset voltage to the first adjustment circuit.

[0053] In a possible implementation, the backlight control method may further include:

[0054] If the preset voltage at the first end of the first switch circuit is greater than a preset threshold, the first switch circuit sends an interrupt request signal to the processor;

[0055] The processor controls the first switch circuit to be disconnected according to the interrupt request signal until the processor does not receive the interrupt request signal.

[0056] In a possible implementation, the backlight control method may further include:

[0057] If the preset voltage at the first end of the first switch circuit is greater than a preset threshold, sending an interrupt request signal to the processor;

[0058] The processor is also used to control the reduction of the brightness of the backlight module according to the interrupt request signal until the processor does not receive the interrupt request signal.

[0059] In a possible implementation, the backlight control circuit further includes a second switch circuit and a switch control circuit, and the method may further include:

[0060] When the processor detects that there is no voltage at the input end of the charging circuit and there is voltage in the charging circuit, the second switch circuit is controlled to be turned on, and the first switch circuit is controlled to be turned off through the switch control circuit.

[0061] In a possible implementation, the switch control circuit includes a first resistor, a second resistor, and a diode, and controlling the first switch circuit to be disconnected by the switch control circuit may include:

[0062] The processor controls the first switch circuit to be disconnected through the first resistor, the second resistor and the diode;

[0063] One end of the first resistor is connected to the output end of the diode, one end of the second resistor is connected to the input end of the diode, the other end of the second resistor is connected to the processor, and the input end of the diode is also connected to the first switch circuit.

[0064] In a third aspect, an embodiment of the present application further provides a terminal device, which may include a battery, a backlight control circuit and a backlight module;

[0065] Among them, the backlight control circuit is the backlight control circuit shown in any embodiment of the first aspect above.

[0066] The backlight control circuit, method and terminal device provided in the embodiments of the present application include a charging circuit, a first switch circuit, a first adjustment circuit and a processor; wherein the charging circuit includes a second adjustment circuit; wherein the input end of the charging circuit is connected to the output end of the power supply, and the input / output end of the charging circuit is connected to the battery, so that when the power supply provides a first voltage to the charging circuit of the mobile phone, the charging circuit converts the first voltage input by the power supply to obtain a second voltage, and inputs the second voltage to the battery to complete charging of the battery; in addition, when providing the required voltage for the backlight module to control the display brightness of the backlight module, the preset end of the charging circuit is connected to the first end of the first switch circuit, the second end of the first switch circuit is connected to the processor, the third end of the first switch circuit is connected to the input end of the first adjustment circuit, and the output end of the first adjustment circuit is connected to the backlight module of the terminal device; the charging circuit The circuit is used to receive a first voltage input by a power source, and input a second voltage obtained by conversion processing to a battery; the charging circuit is also used to input a preset voltage to the first switch circuit through a preset end, and the preset voltage is a voltage that has not been adjusted by the second adjustment circuit of the charging circuit; the processor is used to control the first switch circuit to be turned on when a voltage is detected at the input end of the charging circuit; the first adjustment circuit is used to adjust the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and input the conditioned third voltage to the backlight module to control the display brightness of the backlight module through the third voltage, thereby providing the required voltage for the backlight module, so that when the terminal device is charged and used, in the process from the first voltage output by the power source to the required third voltage provided for the backlight module, the first voltage only undergoes one power conversion of the first adjustment circuit, thereby improving the conversion efficiency of the mobile phone backlight power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 A schematic diagram of the structure of a backlight control circuit provided in an embodiment of the present application;

[0068] Figure 2 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application;

[0069] Figure 3 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application;

[0070] Figure 4 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application;

[0071] Figure 5 A schematic diagram of the structure of a backlight control circuit provided in an embodiment of the present application;

[0072] Figure 6 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application;

[0073] Figure 7 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application;

[0074] Figure 8 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application;

[0075] Fig. 9 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application;

[0076] Fig.10 A schematic diagram of a flow chart of a backlight control method provided in an embodiment of the present application;

[0077] Fig.11 A schematic diagram of the structure of a terminal device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0078] The embodiments of the present application can be applied to a scenario in which a terminal device is used while being charged. When the power supply provides a voltage to the charging IC of the terminal device through a Universal Serial Bus (USB) interface, the voltage can be 5V, 9V, 12V, 20V, etc. When the charging IC of the terminal device receives the voltage provided through the USB interface, it can charge the battery of the terminal device through the input / output interface of the charging IC. When the user uses the terminal device, the output end of the charging IC provides a voltage to the backlight module to control the display brightness of the backlight module for user use.

[0079] Among them, the terminal device can be a device with a charging function and a screen display function, such as a mobile phone, a tablet computer, a laptop computer, a PDA, a wearable device, a vehicle-mounted terminal, a virtual reality (VR) device, etc. Among them, wearable devices include, for example: smart watches, smart bracelets. For example, taking a mobile phone as an example, when a mobile phone is being used while charging, the conversion efficiency of the backlight power supply is usually improved to achieve the purpose of improving the charging efficiency of the mobile phone. When improving the conversion efficiency of the backlight power supply, it is achieved by replacing a high-efficiency backlight IC, but the price of a high-efficiency backlight IC is relatively high, which will increase the cost of the mobile phone. In order to improve the conversion efficiency of the backlight power supply of a mobile phone without increasing the cost, an embodiment of the present application provides a backlight control circuit, which includes a charging circuit, a first switching circuit, a first adjustment circuit and a processor; wherein the charging circuit includes a second adjustment circuit; wherein the input end of the charging circuit is connected to the output end of the power supply, and the input / output end of the charging circuit is connected to the battery, so that when the power supply provides a first voltage to the charging circuit of the mobile phone, the charging circuit converts the first voltage input by the power supply to obtain a second voltage, and inputs the second voltage to the battery to complete the charging of the battery; in addition, when providing the required voltage to the backlight module to control the display brightness of the backlight module, the preset end of the charging circuit is connected to the first end of the first switching circuit, the second end of the first switching circuit is connected to the processor, the third end of the first switching circuit is connected to the input end of the first adjustment circuit, and the output end of the first adjustment circuit is connected to the The terminal device is connected to the backlight module; the charging circuit is used to receive a first voltage input by a power supply, and input a second voltage obtained by conversion processing to a battery; the charging circuit is also used to input a preset voltage to the first switch circuit through a preset end, and the preset voltage is a voltage that has not been adjusted by the second adjustment circuit of the charging circuit; the processor is used to control the first switch circuit to be turned on when a voltage is detected at the input end of the charging circuit; the first adjustment circuit is used to adjust the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and input the conditioned third voltage to the backlight module to control the display brightness of the backlight module through the third voltage, thereby providing the required voltage for the backlight module, so that when the terminal device is charged and used, in the process from the first voltage output by the power supply to the required third voltage provided for the backlight module, the first voltage only undergoes one power conversion of the first adjustment circuit, thereby improving the conversion efficiency of the mobile phone backlight power supply.

[0080] The processor may be an application processor (AP) or a central processing unit (CPU). For example, when the terminal device is a mobile phone or a tablet computer, the processor may be an AP, and when the terminal device is a notebook computer, the processor may be a CPU.

[0081] It should be noted that in the embodiment of the present application, by connecting the preset end of the charging circuit to the first end of the first switch circuit so as to input a preset voltage to the first switch circuit through the charging circuit, the preset end can be set in two different ways. In one possible implementation, the preset end can be the first output end of the charging circuit, and the first output end is a port between the MOS tube passing through the charging circuit and the second adjustment circuit. In another possible implementation, the preset end can be the input end of the charging circuit, that is, the voltage of the power supply output end is directly input to the first switch circuit, thereby inputting the preset voltage to the first switch circuit through the charging circuit. In order to more clearly describe the possible technical solutions provided in the embodiment of the present application, the following will be combined with Figure 1-Figure 4 The technical solution of the backlight control circuit provided in the embodiment of the present application is described in detail.

[0082] In a possible implementation, the preset end is the first output end of the charging circuit, that is, when the first output end of the charging circuit is connected to the first end of the first switch circuit, see Figure 1 As shown, Figure 1 A schematic diagram of the structure of a backlight control circuit provided in an embodiment of the present application, the backlight control circuit may include:

[0083] A charging circuit, a first switch circuit, a first adjustment circuit and a processor; wherein the charging circuit includes a second adjustment circuit;

[0084] Among them, the input end of the charging circuit is connected to the output end of the power supply, the input / output end of the charging circuit is connected to the battery, the first output end of the charging circuit is connected to the first end of the first switching circuit, the second end of the first switching circuit is connected to the processor, the third end of the first switching circuit is connected to the input end of the first adjustment circuit, and the output end of the first adjustment circuit is connected to the backlight module of the terminal device.

[0085] The charging circuit is used for receiving a first voltage inputted from a power source, and converting and processing a second voltage to input into a battery.

[0086] The charging circuit is further used to input a preset voltage to the first switch circuit through the first output terminal, where the preset voltage is a voltage that has not been adjusted by the second adjustment circuit of the charging circuit.

[0087] The processor is used for controlling the first switch circuit to conduct when detecting that there is voltage at the input end of the charging circuit.

[0088] The first adjustment circuit is used for adjusting the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and inputting the conditioned third voltage to the backlight module to control the display brightness of the backlight module through the third voltage.

[0089] By way of example, the charging circuit may be a Charge-IC. When the charging circuit may be a Charge-IC, the charging circuit further comprises a first current limiting circuit, a first MOS transistor, a control subcircuit and a second MOS transistor. Among them, the input end of the first current limiting circuit is connected to the output end of the power supply, the output end of the first current limiting circuit is respectively connected to the first end of the first MOS transistor and the first end of the control subcircuit, the second end of the MOS transistor is connected to the first end of the second adjustment circuit, the second end of the second adjustment circuit is respectively connected to the second end of the control submodule and the first end of the second MOS transistor, and the second end of the second MOS transistor is connected to the battery. By way of example, the power supply may be a USB power supply.

[0090] It should be noted that when the charging circuit further includes a first current limiting circuit, a first MOS tube, a control subcircuit and a second MOS tube, the first output end in the embodiment of the present application is an output end between the second end of the MOS tube and the first end of the second adjustment circuit, that is, the second end of the MOS tube and the first end of the second adjustment circuit are respectively connected to the first switch circuit through the first output end, so that a preset voltage is input to the first switch circuit through the first output end. For example, in the embodiment of the present application, the first output end can be any one of a power midpoint (Power Midpoint, PMID), a midpoint (Midpoint, MID), a USB midpoint (Universal Serial Bus Midpoint, USB_MID), a charging power midpoint (Charge Voltage Midpoint, CHG_VMID) and a power midpoint (Voltage Midpoint, VMID). Of course, the embodiment of the present application is only described by taking the above-mentioned examples, but it does not mean that the embodiment of the present application is limited to this.

[0091] Optionally, the first switching circuit can be any one of a MOS tube, a triode, a transistor and a load switch. Of course, it can also be other circuits having the function of the first switching circuit. Here, the embodiment of the present application is only illustrated by taking the first switching circuit as any one of a MOS tube, a triode, a transistor and a load switch as an example, but it does not mean that the embodiment of the present application is limited to this.

[0092] It can be seen that, in the backlight control circuit provided in the embodiment of the present application, when the power supply provides voltage to the charging circuit, the first voltage at the input end of the charging circuit is first limited by the first current limiting circuit, and a part of the voltage after the current limiting is input to the battery through the second MOS tube, so as to realize charging the battery. In addition, another part of the voltage after the current limiting is input to the first switch circuit through the first MOS tube through the first output end between the first MOS tube and the second adjustment circuit. When the processor detects that there is voltage at the input end of the charging circuit, it controls the first switch circuit to be turned on, so that the first adjustment circuit adjusts the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and inputs the conditioned third voltage to the backlight module, so as to control the display brightness of the backlight module through the third voltage, thereby realizing providing the required voltage for the backlight module. In this way, when the terminal device is charged and used, in the process from the first voltage output by the power supply to the required third voltage provided for the backlight module, the first voltage only undergoes one power conversion of the first adjustment circuit, thereby improving the conversion efficiency of the mobile phone backlight power supply.

[0093] It should be noted that the first adjustment circuit can be a boost circuit or a buck circuit, and similarly, the second adjustment circuit can also be a boost circuit or a buck circuit. In actual charging applications, when the second adjustment circuit is a buck circuit, the first adjustment circuit is a boost circuit; or, when the second adjustment circuit is a boost circuit, the first adjustment circuit is a buck circuit. In OTG mode, when the second adjustment circuit is a boost circuit, the first adjustment circuit is also a boost circuit.

[0094] In actual application, taking the first adjustment circuit as the backlight Boost circuit, the second adjustment circuit as the BuckBoost circuit, and the first voltage of the power input as 5V as an example, the first voltage is first converted by the first MOS tube, and the on-resistance of the first MOS tube is less than 10mohm. Taking the 2A current as an example, the voltage after conversion by the first MOS tube is 4.98V, and the voltage is input to the battery through the Buck Boost circuit and the second MOS tube to charge the battery. At the same time, the voltage is input to the first switch circuit through the PMID. When the processor detects the 4.98V voltage at the input end of the Charge-IC, it indicates that the power supply is currently providing voltage to the Charge-IC. At this time, the processor controls the first switch circuit to conduct, so as to input the 4.98V voltage to the backlight Boost circuit. When the backlight module includes 36 lamp beads (LEDs), the composition of the 36 lamp beads is that 9 lamp beads are connected in series to form a group, and then 4 groups are connected in parallel to form a backlight module structure. The voltage required for each lamp bead is 3V, then the corresponding voltage should be The backlight module provides a 27V voltage. Since the current voltage is only 4.98V, the 4.98V voltage needs to be boosted by the backlight boost circuit first, so that the voltage output by the backlight boost circuit is 27V, and the 27V voltage is input to the backlight module to control the display brightness of the backlight module through the 27V voltage, thereby providing the required voltage for the backlight module. In this way, when the terminal device is charged and used, the process from the 5V voltage output by the power supply to the required 27V voltage provided for the backlight module only requires one power conversion by the first adjustment circuit, thereby improving the conversion efficiency of the mobile phone backlight power supply. For an example, please refer to Table 1:

[0095] Table 1

[0096]

[0097] In combination with the above Table 1, it can be seen that when the voltage provided to Charge-IC by the power supply is 5V, when a high-efficiency backlight IC is used, the voltage passes through the first MOS tube and the second adjustment circuit of Charge-IC, and the 3.8V voltage is input to the backlight module, the backlight module efficiency is 88%, the conversion efficiency (conversion efficiency is equal to charging IC efficiency * backlight module efficiency) is 79.20%, VBL is 27V, IBL is 80mA, the current consumed by the backlight module is 545mA, the conversion efficiency benefit is 2.70%, and the power consumption benefit is 20mA; when the backlight control voltage provided by the embodiment of the present application is used, the 5V voltage passes through Cha After the first MOS tube of rge-IC, a 4.98V voltage is input to the backlight module, the backlight module efficiency is 88%, the conversion efficiency (conversion efficiency is equal to charging IC efficiency * backlight module efficiency) is 88.00%, VBL is 27V, IBL is 80mA, the current consumed by the backlight module is 490mA, the conversion efficiency benefit is 11.5%, and the power consumption benefit is 75mA; it can be seen that compared with the prior art, the backlight power conversion efficiency benefit of the backlight control circuit provided in the embodiment of the present application is increased by 8.80%, and the power consumption benefit is increased by 55mA, thereby achieving the improvement of the conversion efficiency of the backlight power supply of the terminal device while charging the terminal device.

[0098] In addition, it should be noted that when a voltage is input to the first switch circuit through the PMID, the current provided from the power supply to the backlight module is reduced, so that the actual charging current entering the battery will increase. Compared with the prior art of replacing a high-efficiency backlight IC, it not only reduces the cost, but also improves the actual benefit of the charging current and the benefit of the charging time. For an example, please refer to the following Table 2:

[0099] Table 2

[0100]

[0101]

[0102] In combination with the above Table 2, it can be seen that when the current provided to the Charge-IC by the power supply is 2000mA, when a high-efficiency backlight IC is used, the 2000mA is shunted after passing through the first MOS tube, wherein 545mA of the current is input to the backlight module, 1455mA of the current passes through the Buck Boost circuit and the second MOS tube, and is input to the battery to 1723.03mA, and the charging time is 167.15min, the actual charging benefit is 23.68mA, the charging time benefit is 2.33min, the actual charging current benefit is 1.39%, and the charging time benefit is 1.37%; when the backlight control voltage provided in the embodiment of the present application is used, the 2000mA is shunted after passing through the first MOS tube, wherein 490mA of the current is input to the backlight module through the PMID, and 1510mA of the current passes through the Buck Boost circuit and the second MOS tube, and input to the battery is 1788.16mA, and the charging time is 161.06min, the actual charging benefit is 88.82mA, the charging time benefit is 8.42min, the actual charging current benefit is 5.22%, and the charging time benefit is 4.97%; it can be seen that compared with the prior art, the actual charging current benefit of the backlight control circuit provided in the embodiment of the present application is increased by 3.83%, and the charging time benefit is increased by 3.6%, thereby achieving charging for the terminal device while improving the conversion efficiency of the backlight power supply of the terminal device.

[0103] Above Figure 1 The embodiment shown describes in detail the implementation principle and beneficial effects of the backlight control circuit provided by the present application when the preset terminal is the first output terminal of the charging circuit. The implementation principle and beneficial effects of the backlight control circuit provided by the present application when the preset terminal is the input terminal of the charging circuit will be described in detail below. Figure 2-Figure 4 As shown:

[0104] In another possible implementation, when the input end of the charging circuit is connected to the first end of the first switch circuit, in order to prevent the power supply from being burned out, the first switch circuit is a switch circuit with a current limiting control function. For example, the current limiting control function can be implemented through the Fault pin, see Figure 2 As shown, Figure 2 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application, the backlight control circuit may include:

[0105] A charging circuit, a first switch circuit, a first adjustment circuit and a processor; wherein the charging circuit includes a second adjustment circuit;

[0106] Among them, the input end of the charging circuit is connected to the output end of the power supply, the input / output end of the charging circuit is connected to the battery, the input end of the charging circuit is connected to the first end of the first switching circuit, the second end of the first switching circuit is connected to the processor, the third end of the first switching circuit is connected to the input end of the first adjustment circuit, and the output end of the first adjustment circuit is connected to the backlight module of the terminal device.

[0107] The charging circuit is used for receiving a first voltage inputted from a power source, and converting and processing a second voltage to input into a battery.

[0108] The charging circuit is further used to input a preset voltage (ie, a first voltage) to the first switch circuit through an input terminal, where the preset voltage is a voltage that has not been adjusted by the second adjustment circuit of the charging circuit.

[0109] The processor is used for controlling the first switch circuit to conduct when detecting that there is voltage at the input end of the charging circuit.

[0110] The first adjustment circuit is used for adjusting the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and inputting the conditioned third voltage to the backlight module to control the display brightness of the backlight module through the third voltage.

[0111] For example, the charging circuit may be a Charge-IC. When the charging circuit may be a Charge-IC, the charging circuit further includes a first current limiting circuit, a first MOS transistor, a control subcircuit, and a second MOS transistor. The input end of the first current limiting circuit is connected to the output end of the power supply, the output end of the first current limiting circuit is respectively connected to the first end of the first MOS transistor and the first end of the control subcircuit, the second end of the MOS transistor is connected to the first end of the second adjustment circuit, the second end of the second adjustment circuit is respectively connected to the second end of the control submodule and the first end of the second MOS transistor, and the second end of the second MOS transistor is connected to the battery.

[0112] Optionally, the first switching circuit can be any one of a MOS tube, a triode, a transistor and a load switch. Of course, it can also be other circuits having the function of the first switching circuit. Here, the embodiment of the present application is only illustrated by taking the first switching circuit as any one of a MOS tube, a triode, a transistor and a load switch as an example, but it does not mean that the embodiment of the present application is limited to this.

[0113] It should be noted that in the embodiment of the present application, since the first switch circuit is a switch circuit with a current limiting control function, when the processor detects that there is a voltage at the input end of the charging circuit, before controlling the first switch circuit to turn on, the processor can first detect the first voltage at the first end of the first switch circuit through the first switch circuit. If the first voltage at the first end of the first switch circuit is less than the preset threshold, a closing request signal is sent to the processor, so that the processor controls the first switch circuit to turn on according to the closing request signal, thereby providing the required voltage to the backlight module through the power supply. In this way, the power conversion from the first voltage of the power supply to the third voltage of the backlight module only undergoes one power conversion of the first adjustment circuit, thereby improving the conversion efficiency of the mobile phone backlight power supply.

[0114] On the contrary, the first switch circuit is also used to send an interrupt request signal to the processor if the first voltage at the first end of the first switch circuit is greater than a preset threshold value; after receiving the interrupt request signal, the processor controls the first switch circuit to disconnect according to the interrupt request signal, and gradually reduces the brightness of the backlight module until the processor does not receive the interrupt request signal; or controls the brightness of the backlight module to be reduced according to the interrupt request signal until the processor does not receive the interrupt request signal, thereby achieving short circuit protection and preventing the charger from burning out.

[0115] It can be seen that, in the backlight control circuit provided in the embodiment of the present application, when the power supply provides voltage to the charging circuit, the first voltage at the input end of the charging circuit is first limited by the first current limiting circuit, and the voltage of the voltage after current limiting is input to the battery through the second MOS tube to realize charging of the battery. In addition, the first voltage can be directly input to the first switch circuit through the input end of the charging circuit (i.e., the output end of the power supply). When the processor detects that there is voltage at the input end of the charging circuit and the first voltage at the first end of the first switch circuit is less than the preset threshold, the first switch circuit is controlled to be turned on, so that the first adjustment circuit adjusts the first voltage according to the voltage of the backlight module when the first switch circuit is turned on, and inputs the conditioned third voltage to the backlight module to control the display brightness of the backlight module through the third voltage, thereby realizing providing the required voltage for the backlight module. In this way, when the terminal device is charged and used, in the process from the first voltage output by the power supply to the required third voltage provided for the backlight module, the first voltage only undergoes one power conversion of the first adjustment circuit, thereby improving the conversion efficiency of the mobile phone backlight power supply.

[0116] It should be noted that the first regulating circuit can be a boost circuit or a buck circuit, and similarly, the second regulating circuit can also be a boost circuit or a buck circuit. In actual application, when the second regulating circuit is a buck circuit, the first regulating circuit is a boost circuit; or, when the second regulating circuit is a boost circuit, the first regulating circuit is a buck circuit.

[0117] In actual application, the first adjustment circuit is a backlight boost circuit, the second adjustment circuit is a buck boost circuit, and the first voltage of the power input is 5V. For example, taking a current of 2A, the first voltage is first converted by a first MOS tube, the on-resistance of the first MOS tube is less than 10mohm, and the voltage after conversion by the first MOS tube is 4.98V, and the voltage is input to the battery through the buck boost circuit and the second MOS tube to charge the battery. At the same time, a 4.98V voltage is input to the first switch circuit through the input end. When the processor detects a 5V voltage at the input end of the charge-IC and the current passing through the first switch circuit is less than a preset threshold, it indicates that the power supply is currently providing voltage to the charge-IC. At this time, the processor controls the first switch circuit to conduct, so that the 4.98V voltage is input to the backlight boost circuit. When the backlight module includes 36 lamp beads (LEDs), the 36 lamp beads are composed of 9 lamp beads connected in series to form a group, and then 4 groups are connected in parallel to form a backlight module structure. Each lamp bead requires If the voltage is 3V, then the corresponding backlight module should be provided with a 27V voltage. Since the current voltage is only 5V, it is necessary to first perform a voltage boost process on the 5V voltage through the backlight Boost circuit, so that the voltage output by the backlight Boost circuit is 27V, and the 27V voltage is input to the backlight module to control the display brightness of the backlight module through the 27V voltage, thereby providing the required voltage for the backlight module. In this way, when the terminal device is charged and used, from the 5V voltage output by the power supply to the required 27V voltage provided for the backlight module, only one power conversion of the first adjustment circuit is performed, thereby improving the conversion efficiency of the mobile phone backlight power supply. Similarly, when the current provided to the Charge-IC by the power supply is 2000mA, when the high-efficiency backlight IC used in the prior art is used or the backlight control circuit provided by the embodiment of the present application is used, the actual benefit of the charging current and the benefit of the charging time can be referred to the above Table 2 and the relevant description of Table 2, and the embodiment of the present application will not be repeated here.

[0118] In addition, it should be noted that when the input end of the charging circuit is connected to the first end of the first switch circuit, and the first switch circuit is a switch circuit without a current limiting control function, in order to avoid the power supply from being burned out, a second current limiting circuit can be set between the input end of the charging circuit and the first end of the first switch circuit. Figure 3 As shown, Figure 3 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application, the backlight control circuit may further include:

[0119] The input end of the second current limiting circuit is connected to the input end of the charging circuit, and the output end of the second current limiting circuit is connected to the first end of the first switch circuit.

[0120] The second current limiting circuit is used to receive a first voltage input by a power supply, and perform current limiting processing on the first voltage to obtain a preset voltage.

[0121] In the embodiment of the present application, a second current limiting circuit is provided between the input end of the charging circuit and the first end of the first switch circuit, so that the first voltage input through the battery input end can be firstly current limited by the second current limiting circuit. For example, the first voltage input through the input end is 5V, and a voltage of 4V is obtained after current limiting by the second current limiting circuit, and the 4V voltage is input to the first switch circuit. When the processor detects the 5V voltage at the input end of the Charge-IC, it indicates that the power supply is currently providing voltage to the Charge-IC. At this time, the processor controls the first switch circuit to be turned on, so that the 4V voltage is input to the backlight Boost circuit. When the backlight module includes 36 lamp beads (LEDs), the composition of the 36 lamp beads is as follows: Every 9 lamp beads are connected in series to form a group, and then 4 groups are connected in parallel to form a backlight module structure. The voltage required for each lamp bead is 3V, and the corresponding voltage should be 27V for the backlight module. Since the current voltage is only 4V, the 4V voltage needs to be boosted by the backlight Boost circuit first, so that the voltage output by the backlight Boost circuit is 27V, and the 27V voltage is input to the backlight module to control the display brightness of the backlight module through the 27V voltage, thereby providing the required voltage for the backlight module. In this way, when the terminal device is charged and used at the same time, in the process from the 5V voltage output by the power supply to the required 27V voltage provided for the backlight module, only one power conversion of the first adjustment circuit is performed, thereby improving the conversion efficiency of the mobile phone backlight power supply.

[0122] Optionally, the second current limiting circuit includes an overcurrent detection circuit, an overtemperature detection circuit, an AND gate and an abnormal state output circuit, see Figure 4 As shown, Figure 4 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application, the backlight control circuit may further include:

[0123] Among them, the first end of the overcurrent detection circuit and the first end of the overtemperature detection circuit are both connected to the input end of the charging circuit, the second end of the overcurrent detection circuit is connected to the first end of the AND gate, the second end of the overtemperature detection circuit is connected to the second end of the AND gate, the third end of the AND gate is connected to the first end of the abnormal state output circuit, and the second end of the abnormal state output circuit is connected to the first end of the first switch circuit.

[0124] Of course, in the embodiment of the present application, the second current limiting circuit including the current detection circuit, the over-temperature detection circuit, the AND gate and the abnormal state output circuit is only used as an example for explanation. It can also be other forms of current limiting circuits. Here, the embodiment of the present application does not make further restrictions.

[0125] Based on the above Figure 1-Figure 4 In any of the backlight control circuits shown in the embodiments, when the input end of the terminal device is not connected to the power supply, but there is voltage in the charging circuit of the terminal device, in order to avoid erroneous switching and control the first switch circuit to close and provide the required voltage to the backlight module, see Figure 5 As shown, Figure 5 This is a structural schematic diagram of a backlight control circuit provided in an embodiment of the present application. Taking the connection between the first output terminal of the charging circuit and the first terminal of the first switch circuit as an example, the backlight control circuit may also include a second switch circuit and a switch control circuit.

[0126] Among them, the first end of the second switch circuit is connected to the second output end of the charging circuit, the second end of the second switch circuit is connected to the processor, and the third end of the second switch circuit is connected to the input end of the first adjustment circuit; the input end of the switch control circuit is connected to the processor, and the output end of the switch control circuit is connected to the third end of the first switch circuit.

[0127] The processor is also used to control the second switch circuit to be turned on and control the first switch circuit to be turned off through the switch control circuit when it is detected that there is no voltage at the input end of the charging circuit and there is voltage in the charging circuit.

[0128] Optionally, the second switch circuit can also be any one of a MOS tube, a triode, a transistor and a load switch. Of course, it can also be other circuits having the function of the first switch circuit. Here, the embodiment of the present application is only illustrated by taking the first switch circuit as any one of a MOS tube, a triode, a transistor and a load switch as an example, but it does not mean that the embodiment of the present application is limited to this.

[0129] Optionally, the switch control circuit includes a first resistor, a second resistor and a diode; wherein one end of the first resistor is connected to the output end of the diode, one end of the second resistor is connected to the input end of the diode, the other end of the second resistor is connected to the processor, and the input end of the diode is also connected to the third end of the first switch circuit.

[0130] Of course, the diode in the above switch control circuit can also be replaced by a MOS tube or a triode, that is, the switch control circuit can also include a first resistor, a second resistor and a MOS tube, or the switch control circuit can also include a first resistor, a second resistor and a triode. For example, when the switch control circuit can also include a first resistor, a second resistor and a MOS tube, the corresponding Figure 6 As shown, Figure 6 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application.

[0131] In the embodiment of the present application, by setting the second switch circuit and the switch control circuit, when the input end of the terminal device is not connected to the power supply, but there is voltage in the charging circuit of the terminal device, in order to avoid the control of the first switch circuit to be closed and provide the required voltage to the backlight module due to erroneous switching, the first switch circuit can be controlled to be disconnected by the switch control circuit, and the second switch circuit can be controlled to be turned on, so that when the second switch circuit is turned on, the required voltage is input to the backlight module through the first adjustment circuit, and the display brightness of the backlight module is controlled by the input voltage, thereby providing the required voltage to the backlight module while charging to control the display brightness of the backlight module. It should be noted that when the second switch circuit is controlled to be turned on, and the required voltage is input to the backlight module through the first adjustment circuit, optionally, in order to prevent excessive current, the second switch control circuit can also be a switch circuit with a current limiting control function.

[0132] It should be noted that in the embodiment of the present application, when the first switch circuit is controlled by the switch control circuit, the following Table 3 can be referred to:

[0133] Table 3

[0134] state Charge USB OTG USB OTG Discharge GPIO3_USB_ID 1 0 0 1 GPIO2 1 1 0 0

[0135] EN status 1 0 0 0

[0136] It can be seen from Table 3 above that GPIO3_USB_ID and GPIO2 can form an OR logic gate in hardware. When it is pulled low, the corresponding GPIO3_USB_ID is set to 0. When GPIO3_USB_ID is 0, the EN state of the corresponding first switch circuit is always 0, and the first switch circuit is disconnected. Therefore, the occurrence of erroneous switching can be avoided, so that when the input end of the terminal device is not connected to the power supply, but there is voltage in the charging circuit of the terminal device, the first switch circuit can be controlled to be disconnected and the second switch circuit can be controlled to be turned on through the switch control circuit, so that when the second switch circuit is turned on, the required voltage is input to the backlight module through the first adjustment circuit, and the display brightness of the backlight module is controlled by the input voltage, so as to provide the required voltage to the backlight module while charging to control the display brightness of the backlight module.

[0137] Of course, the above Figure 5 In the embodiment shown in the figure, the technical solution for preventing mis-switching is described in detail by taking the first output terminal of the charging circuit connected to the first terminal of the first switch circuit as an example. Of course, when the input terminal of the charging circuit is connected to the first terminal of the first switch circuit, corresponding to the above Figure 2-Figure 4 As shown, it is also possible to prevent no switching by adding a second switch circuit and a switch control circuit accordingly, see Figure 7-Figure 9 As shown, Figure 7A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application is shown in FIG. Figure 8 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application is shown in FIG. Fig. 9 A schematic diagram of the structure of another backlight control circuit provided in an embodiment of the present application.

[0138] Fig.10 A flow chart of a backlight control method provided in an embodiment of the present application is shown. The backlight control method can be applied to a backlight control circuit. The backlight control circuit includes a charging circuit, a first switch circuit, a first adjustment circuit and a processor. The charging circuit includes a second adjustment circuit. Fig.10 As shown, the backlight control method may include:

[0139] S1001. A charging circuit receives a first voltage inputted from a power source, converts the first voltage into a second voltage and inputs it into a battery.

[0140] S1002: The charging circuit inputs a preset voltage to the first switch circuit through a preset terminal of the charging circuit, where the preset voltage is a voltage that has not been adjusted by the second adjustment circuit of the charging circuit.

[0141] S1003: When the processor detects that there is voltage at the input end of the charging circuit, the processor controls the first switch circuit to be turned on.

[0142] S1004: When the first switch circuit is turned on, the first adjustment circuit adjusts the preset voltage according to the voltage of the backlight module, and inputs the conditioned third voltage to the backlight module to control the display brightness of the backlight module through the third voltage.

[0143] It can be seen that in the backlight control method provided in the embodiment of the present application, when the power supply provides voltage to the charging circuit, the charging circuit receives the first voltage input by the power supply, and on the one hand, inputs the second voltage obtained by conversion processing to the battery to realize charging of the battery, and on the other hand, inputs a preset voltage to the first switch circuit through the preset end of the charging circuit, and the preset voltage is a voltage that has not been adjusted by the second adjustment circuit of the charging circuit; when the processor detects that there is voltage at the input end of the charging circuit, it controls the first switch circuit to be turned on, so that when the first adjustment circuit is turned on, the preset voltage is adjusted according to the voltage of the backlight module, and the conditioned third voltage is input to the backlight module to control the display brightness of the backlight module through the third voltage, thereby realizing providing the required voltage for the backlight module. In this way, when the terminal device is charged and used at the same time, in the process from the first voltage output by the power supply to the required third voltage provided for the backlight module, the first voltage only undergoes one power conversion of the first adjustment circuit, thereby improving the conversion efficiency of the mobile phone backlight power supply.

[0144] Optionally, the preset end is a first output end of a charging circuit, the charging circuit includes a first current limiting circuit, and the charging circuit inputs a preset voltage to the first switch circuit through the preset end of the charging circuit, including:

[0145] The first current limiting circuit performs current limiting processing on the first preset voltage to obtain the preset voltage, and inputs the preset voltage to the first switch circuit through the first output terminal, thereby preventing the charger from burning out due to excessive current, and realizing current limiting control of the preset voltage.

[0146] Optionally, the preset end is an input end of a charging circuit, and the charging circuit inputs a preset voltage to the first switch circuit through the preset end of the charging circuit, including:

[0147] The charging circuit inputs a preset voltage to the first switch circuit through an input terminal of the charging circuit.

[0148] Optionally, the backlight control circuit includes a second current limiting circuit, and the first adjustment circuit adjusts the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and before the conditioned third voltage is input to the backlight module, it also includes:

[0149] The second current limiting circuit receives a first voltage input by a power supply, and performs current limiting processing on the first voltage to obtain a preset voltage, so that the first voltage input through the battery input terminal can be firstly current limited by the second current limiting circuit, thereby preventing the charger from being burned out due to excessive current, and realizing current limiting control of the preset voltage.

[0150] Optionally, the first switch circuit is a switch circuit with a current limiting control function, and the first adjustment circuit adjusts the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and before the conditioned third voltage is input to the backlight module, it also includes:

[0151] The first switch circuit detects a preset voltage at a first end of the first switch circuit, and sends a closing request signal to the processor if the preset voltage at the first end of the first switch circuit is less than a preset threshold.

[0152] The processor also controls the first switch circuit to conduct according to the closing request signal, so as to input a preset voltage to the first adjustment circuit.

[0153] Optionally, the backlight control method may further include:

[0154] If the preset voltage at the first end of the first switch circuit is greater than a preset threshold, the first switch circuit sends an interrupt request signal to the processor.

[0155] The processor controls the first switch circuit to be disconnected according to the interrupt request signal until the processor does not receive the interrupt request signal.

[0156] Optionally, the backlight control method may further include:

[0157] If the preset voltage at the first end of the first switch circuit is greater than a preset threshold, an interrupt request signal is sent to the processor.

[0158] The processor is also used to control the reduction of the brightness of the backlight module according to the interrupt request signal until the processor does not receive the interrupt request signal.

[0159] Optionally, the backlight control circuit further includes a second switch circuit and a switch control circuit, and the backlight control method may further include:

[0160] When the processor detects that there is no voltage at the input end of the charging circuit and there is voltage in the charging circuit, the second switch circuit is controlled to be turned on, and the first switch circuit is controlled to be disconnected through the switch control circuit, so as to avoid the occurrence of erroneous switching, so that when the input end of the terminal device is not connected to the power supply, but there is voltage in the charging circuit of the terminal device, the first switch circuit can be controlled to be disconnected and the second switch circuit can be controlled to be turned on through the switch control circuit, so that when the second switch circuit is turned on, the required voltage is input to the backlight module through the first adjustment circuit, and the display brightness of the backlight module is controlled by the input voltage, so as to provide the required voltage to the backlight module while charging to control the display brightness of the backlight module.

[0161] Optionally, the switch control circuit includes a first resistor, a second resistor, and a diode, and controlling the first switch circuit to be disconnected by the switch control circuit includes:

[0162] The processor controls the first switch circuit to be disconnected through the first resistor, the second resistor and the diode.

[0163] One end of the first resistor is connected to the output end of the diode, one end of the second resistor is connected to the input end of the diode, the other end of the second resistor is connected to the processor, and the input end of the diode is also connected to the first switch circuit.

[0164] The backlight control method shown in the embodiment of the present application can implement the technical solution of the backlight control circuit shown in any of the above embodiments, and its implementation principles and beneficial effects are similar, which will not be repeated here.

[0165] Fig.11 For a schematic diagram of a terminal device provided in an embodiment of the present application, see Fig.11 As shown, the terminal device may include a battery, a backlight control circuit and a backlight module.

[0166] The backlight control circuit is the backlight control circuit shown in any of the above embodiments.

[0167] The terminal device shown in the embodiment of the present application can execute the technical solution of the backlight control circuit shown in any of the above embodiments, and its implementation principles and beneficial effects are similar, which will not be repeated here.

[0168] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A backlight control circuit, characterized in that: include: A charging circuit, a first switch circuit, a first adjustment circuit and a processor; wherein the charging circuit includes a second adjustment circuit; The input end of the charging circuit is connected to the output end of the power supply, the input / output end of the charging circuit is connected to the battery, the preset end of the charging circuit is connected to the first end of the first switch circuit, the second end of the first switch circuit is connected to the processor, the third end of the first switch circuit is connected to the input end of the first adjustment circuit, and the output end of the first adjustment circuit is connected to the backlight module of the terminal device; The charging circuit is used to receive a first voltage inputted from the power source, and convert the first voltage obtained by the conversion process into a second voltage inputted to the battery; The charging circuit is further configured to input a preset voltage to the first switch circuit through the preset terminal, wherein the preset voltage is a voltage that has not been adjusted by the second adjustment circuit; The processor is used to control the first switch circuit to be turned on when detecting that there is a voltage at the input end of the charging circuit; The first adjustment circuit is used for adjusting the preset voltage according to the voltage of the backlight module when the first switch circuit is turned on, and inputting the conditioned third voltage into the backlight module to control the display brightness of the backlight module through the third voltage; The circuit also includes a second switch circuit and a switch control circuit; Wherein, the first end of the second switch circuit is connected to the second output end of the charging circuit, the second end of the second switch circuit is connected to the processor, and the third end of the second switch circuit is connected to the input end of the first adjustment circuit; the input end of the switch control circuit is connected to the processor, and the output end of the switch control circuit is connected to the third end of the first switch circuit; The processor is further configured to control the second switch circuit to be turned on and control the first switch circuit to be turned off through the switch control circuit when it is detected that there is no voltage at the input end of the charging circuit and there is voltage in the charging circuit; The charging circuit also includes a first current limiting circuit, a first MOS transistor, a control subcircuit and a second MOS transistor; Wherein, the input end of the first current limiting circuit is connected to the output end of the power supply, the output end of the first current limiting circuit is respectively connected to the first end of the first MOS transistor and the first end of the control subcircuit, the second end of the first MOS transistor is connected to the first end of the second adjustment circuit, the second end of the second adjustment circuit is respectively connected to the second end of the control submodule and the first end of the second MOS transistor, and the second end of the second MOS transistor is connected to the battery; The preset end is the first output end of the charging circuit, and the second end of the first MOS tube and the first end of the second adjustment circuit are respectively connected to the first switch circuit through the first output end.

2. The circuit according to claim 1, characterized in that The switch control circuit includes a first resistor, a second resistor and a diode; One end of the first resistor is connected to the output end of the diode, one end of the second resistor is connected to the input end of the diode, the other end of the second resistor is connected to the processor, and the input end of the diode is also connected to the third end of the first switch circuit.

3. The circuit according to claim 1 or 2, characterized in that: When the second regulating circuit is a step-down circuit, the first regulating circuit is a step-up circuit; or when the second regulating circuit is a step-up circuit, the first regulating circuit is a step-down circuit.

4. The circuit according to claim 1, characterized in that The first output end is any one of a power midpoint PMID, a midpoint MID, a USB midpoint USB_MID, a charging power midpoint CHG_VMID, and a power midpoint VMID.

5. The circuit according to claim 1 or 2, characterized in that: The second switch circuit is a switch circuit with a current limiting control function.

6. The circuit according to claim 1 or 2, characterized in that: The first switch circuit is any one of a MOS tube, a triode, a transistor and a load switch.

7. A backlight control method, characterized in that: Applied to a backlight control circuit, the backlight control circuit includes a charging circuit, a first switch circuit, a first adjustment circuit and a processor, wherein the charging circuit includes a second adjustment circuit, and the method includes: The charging circuit receives a first voltage input from a power source, converts the first voltage into a second voltage and inputs it into the battery; The charging circuit inputs a preset voltage to the first switch circuit through a preset terminal of the charging circuit, wherein the preset voltage is a voltage that has not been adjusted by the second adjustment circuit of the charging circuit; When the processor detects that there is a voltage at the input end of the charging circuit, the processor controls the first switch circuit to be turned on; When the first switch circuit is turned on, the first adjustment circuit adjusts the preset voltage according to the voltage of the backlight module, and inputs the conditioned third voltage to the backlight module to control the display brightness of the backlight module through the third voltage; The backlight control circuit further includes a second switch circuit and a switch control circuit, and the method further includes: When the processor detects that there is no voltage at the input end of the charging circuit and there is voltage in the charging circuit, the processor controls the second switch circuit to be turned on, and controls the first switch circuit to be turned off through the switch control circuit; The preset end is a first output end of the charging circuit, the charging circuit includes a first current limiting circuit, and the charging circuit inputs a preset voltage to the first switch circuit through the preset end of the charging circuit, including: The first current limiting circuit performs current limiting processing on a first preset voltage to obtain the preset voltage, and inputs the preset voltage to the first switch circuit through the first output terminal.

8. The method according to claim 7, characterized in that The switch control circuit includes a first resistor, a second resistor and a diode, and controlling the first switch circuit to be disconnected by the switch control circuit includes: The processor controls the first switch circuit to be disconnected through the first resistor, the second resistor and the diode; One end of the first resistor is connected to the output end of the diode, one end of the second resistor is connected to the input end of the diode, the other end of the second resistor is connected to the processor, and the input end of the diode is also connected to the first switch circuit.

9. A terminal device, characterized in that: Including battery, backlight control circuit and backlight module; Wherein, the backlight control circuit is the backlight control circuit described in any one of claims 1 to 6.

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