Power supply circuit, electronic device and power supply driving method

Abstract

The present application discloses a power supply circuit, an electronic device and a power supply driving method, which belong to the field of integrated circuits. The power supply circuit includes a voltage adjustment unit, a current detection element, a driving chip and a processing unit, wherein the first end of the voltage adjustment unit is connected to an input voltage, the second end of the voltage adjustment unit is used to access a control signal, and the third end of the voltage adjustment unit is connected to the first end of the current detection element; the second end of the current detection element is connected to the first end of the driving chip, and is used to detect the current value of the current on the first end of the driving chip; the first end of the driving chip is used to receive the first voltage output by the third end of the voltage adjustment unit, and the second end of the driving chip is used to output a driving voltage; the processing unit is connected to the current detection element, the processing unit is connected to the second end of the voltage adjustment unit, and the processing unit adjusts the working mode of the voltage adjustment unit according to the current value.

Description

Technical Field

[0001] The present application belongs to the field of integrated circuits, and specifically relates to a power supply circuit, an electronic device, and a power supply driving method. Background Art

[0002] For example, screens are used in various smart terminal devices such as mobile phones and folding machines. The screen needs an OLED (Organic Light-Emitting Diode) driver chip to provide three voltages AVDD, ELVDD, and ELVSS at the same time. The three voltage power supplies power the pixel driving circuit of the screen.

[0003] The driver chip usually realizes the corresponding three-way voltage output by a circuit composed of multiple transistors, in which each transistor is composed of many small MOS tubes connected in parallel, and there may be differences in the process of multiple MOS. The driver chip will face different EOS (Electrical Over Stress) or ESD (Electrical Static Discharge) and other problems, which may cause damage to the integrated circuit and affect the performance and reliability of the whole machine. If there is an overvoltage signal, EOS signal or ESD signal on the input side of the driver chip, the input side will generate a spike of up to 10V when it is powered on, and the energy will cause damage to a small MOS. Most of the MOS still work normally at this time, and the driver chip still functions normally, but the static current will increase a lot.

[0004] The power consumption of the display screen accounts for a large part of the overall power consumption. The power consumption of the display screen when the screen is off is represented by the static current value of the OLED driver chip. If a small MOS is damaged, the static power consumption when the screen is off will increase by dozens of times.

[0005] How to reduce the power consumption of the screen when it is off and ensure the battery life of the entire device is a problem that needs to be solved at present. Summary of the invention

[0006] The purpose of the embodiments of the present application is to provide a power supply circuit, an electronic device and a power supply driving method, which can reduce the power consumption of the screen.

[0007] In a first aspect, an embodiment of the present application provides a power supply circuit, including a voltage adjustment unit, a current detection element, a driver chip and a processing unit.

[0008] The first end of the voltage adjustment unit is connected to the input voltage, the second end of the voltage adjustment unit is used to connect the control signal, and the third end of the voltage adjustment unit is connected to the first end of the current detection element;

[0009] The second end of the current detection element is connected to the first end of the driving chip, and is used to detect the current value of the current on the first end of the driving chip;

[0010] The first end of the driving chip is used to receive the first voltage output by the third end of the voltage adjustment unit, and the second end of the driving chip is used to output the driving voltage;

[0011] The processing unit is connected to the current detection element, the processing unit is connected to the second end of the voltage adjustment unit, and the processing unit adjusts the working mode of the voltage adjustment unit according to the current value.

[0012] In a second aspect, an embodiment of the present application provides an electronic device, comprising a power supply circuit according to the first aspect above.

[0013] In a third aspect, an embodiment of the present application provides a power supply driving method, which is applied to the power supply circuit according to the first aspect above, and the method includes:

[0014] Detecting the current value of the current on the first end of the driving chip by the current detection element;

[0015] Outputting a control signal to the voltage adjustment unit according to the current value by the processing unit;

[0016] adjusting the working mode according to the control signal by the voltage adjustment unit and outputting the first voltage to the first terminal of the driving chip through the third terminal;

[0017] The first voltage is received through a first terminal of the driving chip, and the driving voltage is output through a second terminal of the driving chip.

[0018] In an embodiment of the present application, a current value of the input driver chip is detected before the driver chip, and the working mode of the voltage adjustment unit is controlled according to the current value, so that the driver chip supplies power to the pixel driver circuit according to the voltage output by the voltage adjustment unit after the working mode is adjusted. Therefore, when a small MOS transistor of the driver chip is damaged, the static current of the display screen where the pixel driver circuit is located can be significantly reduced in the screen-off state, thereby reducing the power consumption of the display screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the power supply circuit of an embodiment of the present application.

[0020] Figure 2 It is a structural schematic diagram of the power supply circuit of the first embodiment of the present application.

[0021] Figure 3 It is a schematic diagram of the structure of the voltage adjustment circuit of the first embodiment of the present application.

[0022] Figure 4 It is a structural schematic diagram of the power supply circuit of the second embodiment of the present application.

[0023] Figure 5 It is a flow chart of the power supply driving method according to an embodiment of the present application.

[0024] Figure 6 It is a specific example flow chart of the power supply driving method of an embodiment of the present application. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0026] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0027] The power supply circuit, method and electronic device provided in the embodiments of the present application are described in detail below through specific embodiments and their application scenarios in combination with the accompanying drawings.

[0028] In an embodiment of the present application, a power supply circuit includes a voltage adjustment unit, a current detection element, a driver chip and a processing unit, wherein a first end of the voltage adjustment unit is connected to an input voltage, a second end of the voltage adjustment unit is used to access a control signal, and a third end of the voltage adjustment unit is connected to the first end of the current detection element; the second end of the current detection element is connected to the first end of the driver chip, and is used to detect the current value of the current on the first end of the driver chip; the first end of the driver chip is used to receive a first voltage output by the third end of the voltage adjustment unit, and the second end of the driver chip is used to output a driving voltage; the processing unit is connected to the current detection element, the processing unit is connected to the second end of the voltage adjustment unit, and the processing unit adjusts the working mode of the voltage adjustment unit according to the current value.

[0029] refer to Figure 1 , Figure 1 It is a schematic diagram of the overall structure of the power supply circuit of an embodiment of the present application.

[0030] As shown in the figure, the power supply circuit 100 includes a voltage adjustment unit 10 , a current detection element 20 , a driving chip 30 and a processing unit 40 .

[0031] One end of the voltage adjustment unit 10 is connected to the system voltage VPH, ie, the input voltage. The other end of the voltage adjustment unit 10 is used to receive a control signal. The third end of the voltage adjustment unit 10 is connected to one end of the current detection element 20 .

[0032] The system voltage VPH is input to one end of the voltage adjustment unit 10 . The voltage adjustment unit 10 also receives a control signal from the processing unit 40 to adjust a corresponding working mode according to the control signal.

[0033] The other end of the current detection element 20 is connected to the first end of the driving chip 30, and is used to detect the current value of the current received at the first end of the driving chip 30. The current is output from the third end of the voltage adjustment unit 10 and input to the first end of the driving chip 30 via the current detection element 20. The driving chip 30 is used to generate a driving voltage for the pixel driving circuit according to the current received from the first end and output it from the second end to power the pixel driving circuit.

[0034] The control signal comes from the processing unit 40, which is connected to the current detection element 20, and the processing unit 40 is connected to one end of the voltage adjustment unit 10, so as to send a control signal to the voltage adjustment unit 10 according to the current value detected by the current detection element 20 to adjust the working mode of the voltage adjustment unit 10.

[0035] Optionally, the current detection element includes a precision resistor, and the processing unit includes a first end and a second end, the first end is connected to the first end of the precision resistor, and the second end is connected to the second end of the precision resistor, and is used to obtain the current value by detecting the voltage difference between the first end of the precision resistor and the second end of the precision resistor.

[0036] Optionally, the precision resistor is 3-6 milliohms.

[0037] like Figure 2 As shown, Figure 2 1 is a schematic diagram of the structure of the power supply circuit of the first embodiment of the present application. The voltage adjustment unit 10 outputs the first voltage V1, and after precision resistor voltage division, provides the second voltage V2 to the driver chip 30, so that the driver chip 30 generates three voltages according to the second voltage V2, namely, voltage AVDD, voltage ELVDD and voltage ELVSS, so that the three voltages are used as driving voltages to power the pixel driving circuit of the display screen.

[0038] The processing unit 40 is connected to the left and right ends of the precision resistor respectively. After the voltage adjustment unit 10 outputs the first voltage V1, the corresponding current will flow through the precision resistor, and the precision resistor will divide the first voltage V1 and output the second voltage V2. The first voltage V1 at the left end of the precision resistor and the second voltage V2 at the right end of the precision resistor are detected, and the current value flowing through the precision resistor can be determined based on the voltage difference between the first voltage V1 and the second voltage V2, and the resistance value of the precision resistor. That is, the current value of the input driver chip.

[0039] Optionally, the processing unit is connected to a display screen that provides a driving voltage to a driving chip, and when the display screen is in an off state, the current value is obtained through a current detection element.

[0040] Thus, the processing unit 40 can determine whether a single small transistor of the current driver chip 30 is damaged according to the current value flowing through the precision resistor. When a single small transistor of the driver chip 30 is damaged, other transistors can still work normally, and the driver chip functions normally, but the static current of the driver chip when the display screen is in the off state will increase to dozens of times the normal static current.

[0041] The principle followed by the processing unit 40 in outputting the control signal is: after adjusting the working mode of the voltage adjustment unit 10, the first voltage V1 corresponding to the output of the voltage adjustment unit 10 can be used when a single small parallel transistor in the driver chip 30 is damaged. The driver chip 30 uses the three-way driving voltage generated by the second voltage V2 to power the pixel driving circuit of the display screen, so that the static current of the display screen when the screen is off is minimized.

[0042] Optionally, when detecting that the current value is less than a threshold current, the processing unit outputs a first control signal to the voltage adjustment unit to control the voltage adjustment unit to operate in a pass-through mode, and a first voltage outputted from a third end of the voltage adjustment unit is the same as the input voltage.

[0043] The above threshold current is used to distinguish whether the static current of the driver chip is abnormal or normal when the display screen is in the off state. For example, for a terminal circuit system with a standard voltage of 3V~4.2V, the threshold current is 400 uA.

[0044] That is to say, when the display screen is off, the detection current passing through the precision resistor is the static current of the driver chip. The processing unit can determine whether the small MOS tube of the driver chip is damaged by determining whether the static current is greater than or less than 400 uA.

[0045] The processing unit detects that the current value passing through the precision resistor is less than the threshold current, that is, it determines that the static current of the driver chip is normal when the display screen is in the off state, and then outputs a corresponding control signal to control the voltage adjustment unit to operate in the pass-through mode, that is, the voltage adjustment unit does not make any adjustment to the received system voltage VPH, and directly outputs the system voltage VPH from the third terminal to the input terminal of the driver chip, that is, the value of the output first voltage V1 is equal to the value of the system voltage VPH.

[0046] Optionally, when detecting that the current value is greater than a threshold current, the processing unit detects the voltage value of the input voltage connected to the first end of the voltage adjustment unit, and the processing unit controls the voltage adjustment unit to operate in a boost mode or a buck mode according to the voltage value of the input voltage.

[0047] The processing unit detects that the current value passing through the precision resistor is greater than the threshold current, that is, it determines that the static current of the driver chip is abnormal when the display screen is in the off state, and outputs a corresponding control signal to control the voltage adjustment unit to operate in the boost mode or the buck mode, that is, the voltage adjustment unit needs to boost or buck the received system voltage VPH, so as to reduce the static current on the driver chip at this time.

[0048] In the case where the voltage adjustment unit 10 needs to adjust the system voltage VPH, the voltage adjustment unit 10 outputs the adjusted first voltage V1, that is, the value of the output first voltage V1 may be greater than the system voltage VPH or less than the system voltage VPH according to the adjustment situation, specifically according to the requirements of the control signal output by the processing unit 40. Optionally, in the case where it is detected that the voltage value of the input voltage is greater than the first threshold voltage, the processing unit outputs a second control signal to the voltage adjustment unit to control the voltage adjustment unit to work in the step-down mode, and the first voltage outputted from the third terminal of the voltage adjustment unit is lower than the input voltage.

[0049] Optionally, when it is detected that the voltage value of the input voltage is less than the second threshold voltage, the processing unit outputs a third control signal to the voltage adjustment unit to control the voltage adjustment unit to operate in the boost mode, and the first voltage outputted from the third end of the voltage adjustment unit is higher than the input voltage.

[0050] The first threshold voltage is greater than the second threshold voltage. For example, for a terminal circuit system with a standard voltage of 3V-4.2V, the first threshold voltage is 3.9V and the second threshold voltage is 3.5V.

[0051] The first threshold voltage and the second threshold voltage are determined according to the working mode of the driving chip. The working mode of the driving chip is first described below.

[0052] In an embodiment of the present application, the driver chip is, for example, an active matrix organic light emitting diode panel (ActiveMatrix / OrganicLightEmittingDiode, AMOLED) bias drive circuit, and three working states often occur during operation: when the system voltage VPH is greater than 3.9V, the driver chip works in buck mode; when the system voltage VPH is less than 3.5V, the driver chip works in boost mode; when the system voltage VPH is between 3.5V and 3.9V, the driver chip works in boost-buck mode.

[0053] If the small MOS transistor of the driver chip is damaged, the above three different working modes of the display screen are tested when the display screen is off, and it can be seen that the driver chip will have a constant large static current when it works in buck mode and boost mode. When working in boost-buck mode, the static current of the driver chip is close to the theoretical normal value.

[0054] Therefore, if it is detected that the static current is greater than the threshold current when the display screen is off, the first voltage V1 output by the voltage adjustment unit can be further adjusted to be between the first threshold voltage and the second threshold voltage by judging the size of the system voltage VPH received by the voltage adjustment unit. That is, when the voltage value of the system voltage VPH is greater than the first threshold voltage, the first voltage V1 output by the voltage adjustment unit is adjusted to be lower than the system voltage VPH input to the voltage adjustment unit; when the voltage value of the system voltage VPH is less than the second threshold voltage, the first voltage V1 output by the voltage adjustment unit is adjusted to be higher than the system voltage VPH input to the voltage adjustment unit.

[0055] Therefore, by operating the slightly damaged driver chip in the step-up / step-down mode, the off-screen quiescent current that increases significantly when a single small transistor is damaged can be significantly reduced.

[0056] In one embodiment, the voltage adjustment unit adjusts the working mode through three modes, such as Figure 2 As shown, Figure 2 It is a schematic diagram of the structure of the power supply circuit of the first embodiment of the present application.

[0057] In this embodiment, the voltage adjustment unit includes: a buck mode, ie, a voltage reduction mode; a boost mode, ie, a voltage increase mode; and a pass-through mode.

[0058] In this embodiment, optionally, the voltage adjustment unit includes a first control switch, a second control switch, a third control switch, a fourth control switch and an inductor; wherein, the first end of the first control switch is connected to the input voltage, the second end of the first control switch is connected to the first end of the fourth control switch through the inductor, the second end of the fourth control switch outputs the first voltage, the first end of the second control switch is connected to the second end of the first control switch, the first end of the third control switch is connected to the first end of the fourth control switch, and the second end of the second control switch and the second end of the third control switch are respectively connected to the second voltage end; the control signal includes a first switch control signal, a second switch control signal, a third switch control signal and a fourth switch control signal, the control end of the first control switch is connected to the first switch control signal, the control end of the second control switch is connected to the second switch control signal, the control end of the third control switch is connected to the third switch control signal, and the control end of the fourth control switch is connected to the fourth switch control signal.

[0059] Next, combine Figure 3 The voltage adjustment unit of the first embodiment of the present application is described in detail.

[0060] like Figure 3 As shown, the voltage adjustment unit includes a first control switch Q1, a second control switch Q2, a third control switch Q3, a fourth control switch Q4 and an inductor L. In the illustrated embodiment, each control switch is a MOS transistor, and in other embodiments, each control switch may also be a common switch.

[0061] One end of the first control switch Q1 on the left is connected to the system voltage VPH, the other end of the first control switch Q1 is connected to one end of the second control switch Q2, and the other end of the second control switch Q2 is grounded.

[0062] One end of the fourth control switch Q4 on the right side outputs the first voltage V1 , the other end of the fourth control switch Q4 is connected to one end of the third control switch Q3 , and the other end of the third control switch Q3 is grounded.

[0063] One end of the inductor L is arranged on the connection line between the corresponding connection ends of the first control switch Q1 and the second control switch Q2, and the other end of the inductor L is arranged on the connection line between the corresponding connection ends of the fourth control switch Q4 and the third control switch Q3. That is, the corresponding ends of the first control switch Q1 and the fourth control switch Q4 are connected through the inductor L.

[0064] Therefore, the working mode of the voltage adjustment unit can be adjusted by controlling the on and off of the first control switch Q1 by the first switch control signal, the second control switch Q2 by the second switch control signal, the third control switch Q3 by the third switch control signal, and the fourth control switch Q4 by the fourth switch control signal.

[0065] Optionally, when the voltage adjustment unit operates in the buck mode, the first control switch Q1 and the second control switch Q2 are both in a switching state, the third control switch Q3 is constantly turned off, and the fourth control switch Q4 is constantly turned on; or

[0066] When the voltage adjustment unit operates in the boost mode, the first control switch Q1 is constantly turned on, the second control switch Q2 is constantly turned off, and the third control switch Q3 and the fourth control switch Q4 are both in the switching state; or

[0067] When the voltage adjustment unit operates in the pass mode, the first control switch Q1 and the fourth control switch Q4 are constantly turned on, and the second control switch Q2 and the third control switch Q3 are constantly turned off.

[0068] When the processing unit 40 outputs a control signal and the voltage adjustment unit 10 needs to be adjusted to work in the buck mode, the first control switch Q1 and the second control switch Q2 are set to be in the switch state according to the control signal, the third control switch Q3 is constantly turned off, and the fourth control switch Q4 is constantly turned on. Thus, by switching the first control switch Q1 and the second control switch Q2 on and off, the voltage adjustment unit 10 is adjusted to work in the buck mode.

[0069] Specifically, for example, according to the first voltage value to be adjusted and reduced, the on-time of the first control switch Q1 and the on-time of the second control switch Q2 in each cycle are controlled so that the ratio of the on-time of the first control switch Q1 to the entire cycle meets the required voltage reduction requirement.

[0070] When the processing unit 40 outputs a control signal and the voltage adjustment unit 10 needs to be adjusted to work in the boost mode, the first control switch Q1 is constantly turned on, the second control switch Q2 is constantly turned off, and the third control switch Q3 and the fourth control switch Q4 are both set to be in a switching state according to the control signal. Thus, by switching the third control switch Q3 and the fourth control switch Q4 on and off, the voltage adjustment unit 10 is adjusted to work in the boost mode.

[0071] Specifically, for example, according to the first voltage value to be adjusted and reduced, the on-time of the third control switch Q3 and the on-time of the fourth control switch Q4 in each cycle are controlled so that the ratio of the on-time of the third control switch Q3 to the entire cycle meets the required boost requirement.

[0072] When the processing unit 40 outputs a control signal and the voltage adjustment unit 10 needs to be adjusted to work in the direct-through mode, the first control switch Q1 and the fourth control switch Q4 are constantly turned on, and the second control switch Q2 and the third control switch Q3 are constantly turned off. That is, the system voltage VPH is directly output through the second control switch Q2, the inductor L and the third control switch Q3 in sequence, and V1=VPH.

[0073] In another embodiment, the voltage adjustment unit can adjust the working mode through three other modes, such as Figure 4 As shown, Figure 4 It is a structural schematic diagram of the power supply circuit of the second embodiment of the present application.

[0074] In this embodiment, the voltage adjustment unit includes: a step-down charge pump mode, ie, a step-down mode; a step-up charge pump mode, ie, a step-up mode; and a pass-through mode.

[0075] Optionally, the voltage adjustment unit includes a buck charge pump, a boost charge pump and a pass switch (not shown in the figure). When the voltage adjustment unit is adjusted to work in the buck mode, the buck charge pump is turned on; when the voltage adjustment unit is adjusted to work in the boost mode, the boost charge pump is turned on; when the voltage adjustment unit is adjusted to work in the pass mode, the pass switch is turned on.

[0076] like Figure 4 As shown, except that the implementation method corresponding to the voltage adjustment unit is different from that of the first embodiment of the present application, the working principles of other components are the same and will not be repeated here.

[0077] Optionally, when the voltage adjustment unit operates in the boost mode or the buck mode and the current value obtained by the processing unit is less than the threshold current, the processing unit controls the voltage adjustment unit to switch to a pass-through mode so that the first voltage outputted from the third end of the voltage adjustment unit is the same as the input voltage.

[0078] For the voltage adjustment unit adjusted to the buck mode, the voltage can be stepped down in the following manner:

[0079] Taking the threshold current as 400uA, the first threshold voltage as 3.9V, and the second threshold voltage as 3.5V as an example, when the system voltage VPH>3.9V, the voltage adjustment unit needs to reduce the output first voltage V1 to within the range of 3.5V-3.9V. Preferably, the voltage adjustment unit can be directly adjusted to 3.7V. If after the voltage adjustment, the processing unit detects that the static current of the driver chip can be reduced to below 400uA through the precision resistor, it means that the voltage has been successfully adjusted; if after the voltage adjustment, the processing unit detects that the static current of the driver chip cannot be reduced to below 400uA through the precision resistor, the voltage adjustment unit can traverse the entire interval voltage between 3.5V-3.9V with a certain step, and the processing unit monitors the detection current until the current flowing through the precision resistor is detected to be lower than 400uA. At this time, the processing unit controls the voltage adjustment unit to switch to the pass-through mode, so that the first voltage output by the voltage adjustment unit is the same as the system voltage VPH. Here, the voltage interval of the step traversal can be 50-100 millivolts.

[0080] Similarly, when the system voltage VPH<3.5, the voltage adjustment unit needs to raise the first voltage V1 to the range of 3.5V-3.9V. Preferably, the voltage adjustment unit can choose to directly adjust to 3.7V. If after the voltage adjustment, the processing unit detects that the static current of the driver chip with the screen off can be reduced to below 400uA through the precision resistor, then it means that the voltage has been successfully adjusted; if after the voltage adjustment, the processing unit detects that the static current of the driver chip with the screen off cannot be reduced to below 400uA through the precision resistor, then the voltage adjustment unit can traverse the entire interval voltage between 3.5V-3.9V in a certain step, and the processing unit monitors the detection current until it is lower than 400uA. At this time, the processing unit controls the voltage adjustment unit to switch to the pass-through mode, so that the first voltage output by the voltage adjustment unit is the same as the system voltage VPH. Here, the voltage interval of the step traversal can be 50-100 millivolts.

[0081] Optionally, after the voltage adjustment unit switches from the boost mode or the buck mode to the pass-through mode, the processing unit stops outputting the control signal to the voltage adjustment unit.

[0082] In an embodiment of the present application, a current detection element is provided before the driver chip to detect the current value of the input driver chip, and the working mode of the voltage adjustment unit is controlled and adjusted according to the current value, so that the voltage output by the voltage adjustment unit is adjusted and then input into the driver chip, so that the driver chip outputs the driving voltage according to the adjusted voltage, thereby significantly reducing the static current of the driver chip when a single small transistor is damaged, thereby reducing the power consumption of the display screen when the screen is off.

[0083] Optionally, the processing unit may also obtain the current value through the current detection element when the display screen is in a lit state.

[0084] Due to the working characteristics of the driver chip 30, when the display screen is in the bright screen state and displays normally, due to the heavy load, the second voltage V2 is relatively high, close to the driving voltage ELVDD, which will cause the driver chip 30 to easily work in the diode mode, which will cause the display screen ripple to increase and cause the screen flicker problem. Therefore, in the case of the risk of screen flicker, the working mode of the voltage adjustment unit can be controlled and adjusted.

[0085] At this time, the processing unit 40 can output a corresponding control signal to the voltage adjustment unit 10 according to the current value detected by the current detection element, and adjust the working mode of the voltage adjustment unit 10 to reduce the risk of screen flickering when the display screen is overloaded. The principle followed by the processing unit 40 to output the control signal is that the first voltage V1 output by the voltage adjustment unit 10 after adjustment will not cause the risk of screen flickering.

[0086] If there is a risk of screen flickering on the display, by testing the driver chip in different working modes when the display is normally lit, it can be seen that the driver chip will not enter the diode mode when working in the boost-buck mode.

[0087] Therefore, when the screen is on, if the current value passing through the current detection element is detected, that is, the static current of the driver chip is greater than the target threshold current, for example, 500mA-600mA, the working mode of the voltage adjustment unit can be adjusted so that the first voltage V1 output by the voltage adjustment unit is between the first threshold voltage and the second threshold voltage, that is, the overloaded driver chip is operated in the step-up and step-down mode, which can significantly reduce the risk of screen flickering in the screen-on state.

[0088] Optionally, the present application embodiment further provides an electronic device, including the above Figures 1 to 4 The power supply circuit as described in any embodiment.

[0089] Optionally, the electronic device also includes: a display screen, connected to the second end of the driving chip for receiving the driving voltage; the processing unit is connected to the display screen to obtain the display status of the display screen, and when the display screen is in the off state, the processing unit obtains the current value through the current detection element.

[0090] Optional, such as Figure 5 As shown, the embodiment of the present application also provides a power supply driving method, which is applied to the above Figures 1 to 4 The power supply circuit as described in any embodiment.

[0091] like Figure 5 As shown, the method includes:

[0092] Step 202, detecting the current value of the current on the first end of the driving chip by the current detection element;

[0093] Step 204, outputting a control signal to the voltage adjustment unit according to the current value by the processing unit;

[0094] Step 206, adjusting the working mode according to the control signal by the voltage adjustment unit and outputting the first voltage to the first terminal of the driving chip through the third terminal;

[0095] Step 208 , receiving the first voltage through the first terminal of the driver chip, and outputting the driving voltage through the second terminal of the driver chip.

[0096] Optionally, the current detection element includes a precision resistor, and the processing unit is used to obtain the current value by detecting a voltage difference between a first end of the precision resistor and a second end of the precision resistor.

[0097] Optionally, when detecting that the current value is less than a threshold current, the processing unit outputs a first control signal to the voltage adjustment unit to control the voltage adjustment unit to operate in a pass-through mode, and a first voltage outputted from a third end of the voltage adjustment unit is the same as the input voltage.

[0098] Optionally, when detecting that the current value is greater than a threshold current, the processing unit detects the voltage value of the input voltage connected to the first end of the voltage adjustment unit, and the processing unit controls the voltage adjustment unit to operate in a boost mode or a buck mode according to the voltage value of the input voltage.

[0099] Optionally, when it is detected that the voltage value of the input voltage is greater than the first threshold voltage, the processing unit outputs a second control signal to the voltage adjustment unit to control the voltage adjustment unit to operate in the buck mode, and the first voltage outputted from the third end of the voltage adjustment unit is lower than the input voltage.

[0100] Optionally, when it is detected that the voltage value of the input voltage is less than the second threshold voltage, the processing unit outputs a third control signal to the voltage adjustment unit to control the voltage adjustment unit to operate in the boost mode, and the first voltage outputted from the third end of the voltage adjustment unit is higher than the input voltage.

[0101] Optionally, when the voltage adjustment unit operates in the boost mode or the buck mode and the current value obtained by the processing unit is less than the threshold current, the processing unit controls the voltage adjustment unit to switch to a pass-through mode so that the first voltage outputted from the third end of the voltage adjustment unit is the same as the input voltage.

[0102] Optionally, after the voltage adjustment unit switches from the boost mode or the buck mode to the pass-through mode, the processing unit stops outputting the control signal to the voltage adjustment unit.

[0103] Reference now Figure 6 , Figure 6 This is a specific example flow chart of the power supply driving method of an embodiment of the present application, in which the display screen is in the screen-off state.

[0104] like Figure 6 As shown, the following steps are included:

[0105] Step 302, using a precision resistor to detect the leakage current, i.e., the static current, of the IC, i.e., the driver chip, and sending the detected current data to the processing unit AP;

[0106] Step 304, the AP detects that the IC leakage is > 400uA;

[0107] Step 306, system voltage VPH>3.9V;

[0108] Step 308, the buck module adjusts the output voltage Vin within the range of 3.5-3.9V;

[0109] Step 310, determine whether the IC leakage is less than 400 uA, if so, proceed to step 312, if not, return to step 308;

[0110] Step 312, stop voltage regulation and monitor IC leakage current;

[0111] Step 314, system voltage VPH<3.5V;

[0112] Step 316, the boost module adjusts the output voltage Vin within the range of 3.5-3.9V;

[0113] Step 318, determine whether the IC leakage is less than 400 uA, if so, proceed to step 3202, if not, return to step 316;

[0114] Step 320, stop voltage regulation and monitor IC leakage current;

[0115] Step 322, the AP detects that the IC leakage is less than 400 uA;

[0116] Step 324: the voltage regulating module operates in a pass-through mode.

[0117] In an embodiment of the present application, when the processing unit determines that the detection current is greater than the threshold current, the first control signal is output to the voltage adjustment unit; when the system voltage VPH is greater than the first threshold voltage, the voltage adjustment unit is controlled to adjust the system voltage VPH to decrease according to the first control signal; when the system voltage VPH is less than the second threshold voltage, the voltage adjustment unit is controlled to adjust the system voltage VPH to increase according to the first control signal. In this way, when a small MOS transistor in the driver chip is damaged, the power consumption of the screen can be reduced, and the risk of screen flickering can be reduced when the driver chip is working under high load.

[0118] In an embodiment of the present application, a current value of the input driver chip is detected before the driver chip, and the working mode of the voltage adjustment unit is controlled according to the current value, so that the driver chip supplies power to the pixel driver circuit according to the voltage output by the voltage adjustment unit after the working mode is adjusted. Therefore, when a small MOS transistor of the driver chip is damaged, the static current of the display screen where the pixel driver circuit is located can be significantly reduced in the screen-off state, thereby reducing the power consumption of the display screen.

[0119] In addition, the risk of screen flickering can be reduced when the driver chip is working under heavy load with the screen on.

[0120] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0121] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a terminal (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0122] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A power supply circuit, characterized in that: It includes a voltage adjustment unit, a current detection element, a driver chip and a processing unit. The first end of the voltage adjustment unit is connected to the input voltage, the second end of the voltage adjustment unit is used to connect the control signal, and the third end of the voltage adjustment unit is connected to the first end of the current detection element; The second end of the current detection element is connected to the first end of the driving chip, and is used to detect the current value of the current on the first end of the driving chip; The first end of the driving chip is used to receive the first voltage output by the third end of the voltage adjustment unit, and the second end of the driving chip is used to output the driving voltage; The processing unit is connected to the current detection element, the processing unit is connected to the second end of the voltage adjustment unit, and the processing unit adjusts the working mode of the voltage adjustment unit according to the current value; When the processing unit detects that the current value is less than the threshold current, the processing unit outputs a first control signal to the voltage adjustment unit to control the voltage adjustment unit to operate in a pass-through mode, and the first voltage outputted by the third terminal of the voltage adjustment unit is the same as the input voltage; When detecting that the current value is greater than a threshold current, the processing unit detects the voltage value of the input voltage connected to the first end of the voltage adjustment unit, and the processing unit controls the voltage adjustment unit to operate in a boost mode or a buck mode according to the voltage value of the input voltage.

2. The power supply circuit according to claim 1, characterized in that: The current detection element includes a precision resistor, and the processing unit includes a first end and a second end, the first end is connected to the first end of the precision resistor, and the second end is connected to the second end of the precision resistor, and is used to obtain the current value by detecting the voltage difference between the first end of the precision resistor and the second end of the precision resistor.

3. The power supply circuit according to claim 1, characterized in that: The processing unit controls the voltage adjustment unit to operate in a boost mode or a buck mode according to the voltage value of the input voltage, including: when it is detected that the voltage value of the input voltage is greater than a first threshold voltage, the processing unit outputs a second control signal to the voltage adjustment unit to control the voltage adjustment unit to operate in the buck mode, and the first voltage outputted from the third end of the voltage adjustment unit is lower than the input voltage.

4. The power supply circuit according to claim 1, characterized in that: The processing unit controls the voltage adjustment unit to operate in a boost mode or a buck mode according to the voltage value of the input voltage, including: when it is detected that the voltage value of the input voltage is less than a second threshold voltage, the processing unit outputs a third control signal to the voltage adjustment unit to control the voltage adjustment unit to operate in the boost mode, and the first voltage outputted from the third end of the voltage adjustment unit is higher than the input voltage.

5. The power supply circuit according to claim 1, characterized in that: When the processing unit controls the voltage adjustment unit to operate in a boost mode or a buck mode according to the voltage value of the input voltage, and the voltage adjustment unit operates in the boost mode or the buck mode, and the current value obtained by the processing unit is less than the threshold current, the processing unit controls the voltage adjustment unit to switch to a pass-through mode so that the first voltage outputted from the third end of the voltage adjustment unit is the same as the input voltage.

6. The power supply circuit according to claim 5, characterized in that: After the voltage adjustment unit switches from the boost mode or the buck mode to the pass-through mode, the processing unit stops outputting the control signal to the voltage adjustment unit.

7. The power supply circuit according to any one of claims 1 to 6, characterized in that: The voltage adjustment unit includes a first control switch, a second control switch, a third control switch, a fourth control switch and an inductor; wherein, The first end of the first control switch is connected to the input voltage, the second end of the first control switch is connected to the first end of the fourth control switch through the inductor, and the second end of the fourth control switch outputs the first voltage. The first end of the second control switch is connected to the second end of the first control switch, the first end of the third control switch is connected to the first end of the fourth control switch, and the second end of the second control switch and the second end of the third control switch are respectively connected to a preset voltage end; The control signal includes a first switch control signal, a second switch control signal, a third switch control signal and a fourth switch control signal. The control end of the first control switch is connected to the first switch control signal, the control end of the second control switch is connected to the second switch control signal, the control end of the third control switch is connected to the third switch control signal, and the control end of the fourth control switch is connected to the fourth switch control signal.

8. An electronic device, characterized in that: The invention comprises a power supply circuit according to any one of claims 1 to 7.

9. The electronic device according to claim 8, characterized in that: Also includes: A display screen, connected to the second end of the driving chip for receiving the driving voltage; The processing unit is connected to the display screen to obtain the display status of the display screen. When the display screen is in a screen-off state, the processing unit obtains the current value through the current detection element.

10. A power supply driving method, characterized in that: Applied to the power supply circuit according to any one of claims 1 to 7, the method comprises: Detecting the current value of the current on the first end of the driving chip by the current detection element; Outputting a control signal to the voltage adjustment unit according to the current value by the processing unit; adjusting the working mode according to the control signal by the voltage adjustment unit and outputting the first voltage to the first terminal of the driving chip through the third terminal; The first voltage is received through a first terminal of the driving chip, and the driving voltage is output through a second terminal of the driving chip.

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