Overcurrent protection circuit, control method, DC-DC converter and electronic equipment

Abstract

The embodiment of the present application discloses an overcurrent protection circuit, including: the output end of a DC-DC converter is connected to one end of a current detection resistor, one end of a first switch is respectively connected to the input end of a first comparator and the other end of the current detection resistor, the other end of the first switch is respectively connected to the power supply end of a load device and one end of a second switch, the other end of the second switch is respectively connected to one end of a voltage divider resistor and one end of a third switch, the other end of the third switch is connected to the input end of a second comparator, the output end of the first comparator is respectively connected to the input end of a level conversion circuit and the first end of a processor, the output end of the level conversion circuit is connected to the enable end of a DC-DC converter, the output end of the second comparator is connected to the second end of the processor, the third end of the processor is respectively connected to the control end of the second switch and the control end of the third switch, and the processor is also connected to the control end of the first switch. The embodiment of the present application also provides a control method, a DC-DC converter, and an electronic device.

Description

Technical Field

[0001] The present application relates to an overcurrent protection technology in a direct current-direct current (DC-DC) converter, and in particular to an overcurrent protection circuit, a control method, a DC-DC converter and an electronic device. Background Art

[0002] At present, when the output of a DC-DC converter exceeds the rated current value of the output, the current at the output exceeds the load and is called overcurrent. Overcurrent can damage the internal components of the DC-DC converter. Therefore, in order to protect the DC-DC converter and the front-end circuit system, a suitable protection mechanism is needed to prevent overcurrent.

[0003] In the related art, a DC-DC converter is checked for overcurrent by turning it on and off. If overcurrent does not exist, the DC-DC converter is turned on, and if overcurrent exists, the DC-DC converter is turned off. However, during the period when the DC-DC converter is turned on to check for overcurrent, if overcurrent still exists, the DC-DC converter will be damaged. It can be seen that the existing DC-DC converter has a technical problem of poor reliability. Summary of the invention

[0004] The embodiments of the present application provide an overcurrent protection circuit, a control method, a DC-DC converter and an electronic device, which can improve the reliability of the DC-DC converter.

[0005] The technical solution of this application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides an overcurrent protection circuit, which is used to perform overcurrent protection on a DC-DC converter, and includes: a current detection resistor, a first comparator, a second comparator, a first switch, a second switch, a third switch, a processor, a level conversion circuit, a voltage divider resistor and a power supply, wherein the output end of the DC-DC converter is connected to one end of the current detection resistor, one end of the first switch is respectively connected to the input end of the first comparator and the other end of the current detection resistor, the other end of the first switch is respectively connected to the power supply end of the load device and one end of the second switch, the other end of the second switch is respectively connected to one end of the voltage divider resistor and one end of the third switch, the other end of the third switch is connected to the input end of the second comparator, the output end of the first comparator is respectively connected to the input end of the level conversion circuit and the first end of the processor, the output end of the level conversion circuit is connected to the enable end of the DC-DC converter, the output end of the second comparator is connected to the second end of the processor, the third end of the processor is respectively connected to the control end of the second switch and the control end of the third switch, the processor is also connected to the control end of the first switch, and the other end of the voltage divider resistor is grounded through the power supply; wherein the processor is used to:

[0007] When the overcurrent protection circuit is in the overcurrent protection state and the first output level of the second comparator is the first indication level, controlling the control end of the first switch, the control end of the second switch and the control end of the third switch so that the DC-DC converter enters a power supply state for the load device;

[0008] Among them, the first indication level is used to indicate that the input voltage of the second comparator is greater than the reference voltage of the second comparator; the overcurrent protection state is the state of the overcurrent protection circuit when the first switch is turned off, the second switch is closed, and the third switch is closed; the power supply state is the state of the DC-DC converter being turned on when the first switch is closed, the second switch is turned off, and the third switch is turned off.

[0009] In a second aspect, an embodiment of the present application provides a control method, which is applied to a processor of the overcurrent protection circuit described in one or more of the above embodiments, including:

[0010] When the overcurrent protection circuit is in the overcurrent protection state and the first output level of the second comparator is the first indication level, controlling the control end of the first switch, the control end of the second switch and the control end of the third switch so that the DC-DC converter enters a power supply state for the load device;

[0011] Among them, the first indication level is used to indicate that the input voltage of the second comparator is greater than the reference voltage of the second comparator; the overcurrent protection state is the state of the overcurrent protection circuit when the first switch is turned off, the second switch is closed, and the third switch is closed; the power supply state is the state of the DC-DC converter being turned on when the first switch is closed, the second switch is turned off, and the third switch is turned off.

[0012] In a third aspect, an embodiment of the present application provides a DC-DC converter, comprising the overcurrent protection circuit described in one or more of the above embodiments.

[0013] In a fourth aspect, an embodiment of the present application provides an electronic device, comprising: a DC-DC converter as described in one or more of the above embodiments and a storage medium storing instructions executable by the processor; the storage medium relies on the processor to perform operations through a communication bus, and when the instructions are executed by the processor, the control method described in one or more of the above embodiments is executed.

[0014] In a fifth aspect, an embodiment of the present application provides a computer storage medium storing executable instructions. When the executable instructions are executed by one or more processors, the processor executes the control method described in one or more of the above embodiments.

[0015] The embodiment of the present application provides an overcurrent protection circuit, a control method, a DC-DC converter and an electronic device. The overcurrent protection circuit is used to perform overcurrent protection on the DC-DC converter, including: a current detection resistor, a first comparator, a second comparator, a first switch, a second switch, a third switch, a processor, a level conversion circuit, a voltage divider resistor, and a power supply. The output end of the DC-DC converter is connected to one end of the current detection resistor, one end of the first switch is respectively connected to the input end of the first comparator and the other end of the current detection resistor, the other end of the first switch is respectively connected to the power supply end of the load device and one end of the second switch, the other end of the second switch is respectively connected to one end of the voltage divider resistor and one end of the third switch, the other end of the third switch is connected to the input end of the second comparator, the output end of the first comparator is respectively connected to the input end of the level conversion circuit and the first end of the processor, the output end of the level conversion circuit is connected to the enable end of the DC-DC converter, the output end of the second comparator is connected to the second end of the processor, the third end of the processor is respectively connected to the control end of the second switch and the control end of the third switch, the processor is also connected to the control end of the first switch, and the other end of the voltage divider resistor is grounded through the power supply. The processor is used to: when the overcurrent When the overcurrent protection circuit is in the overcurrent protection state and the first output level of the second comparator is the first indication level, the control end of the first switch, the control end of the second switch and the control end of the third switch are controlled so that the DC-DC converter enters the power supply state for the load device; wherein the first indication level is used to indicate that the input voltage of the second comparator is greater than the reference voltage of the second comparator; that is, by setting the overcurrent protection circuit for the DC-DC converter, when the overcurrent protection circuit performs overcurrent protection on the DC-DC converter, it can be determined whether the input voltage of the second comparator is greater than the reference voltage of the second comparator through the first output level of the second comparator. If greater than, it indicates that the power supply end abnormality of the load device no longer exists, so there is no overcurrent at the output end of the DC-DC converter. At this time, the processor controls the first switch, the second switch and the third switch to switch from the overcurrent protection state of the overcurrent protection circuit to the power supply state of the DC-DC converter for the load device, thereby avoiding the risk of damage to the DC-DC converter caused by the overcurrent switching to the power supply state, so that the DC-DC converter can supply power to the load device in a timely and safe manner, thereby improving the reliability of the DC-DC converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of an optional overcurrent protection circuit provided in an embodiment of the present application;

[0017] Figure 2a Schematic diagram of the overcurrent protection mechanism of the DC-DC converter in the related art Figure 1 ;

[0018] Figure 2bFIG2 is a flow chart of an overcurrent protection mechanism of a DC-DC converter in the related art;

[0019] Figure 3 A schematic diagram of the structure of an optional overcurrent protection circuit according to an embodiment of the present application;

[0020] Figure 4 A schematic diagram of the structure of a second example of an optional overcurrent protection circuit provided in an embodiment of the present application;

[0021] Figure 5 A flowchart of an optional control method provided in an embodiment of the present application;

[0022] Figure 6 A schematic diagram of the structure of an optional DC-DC converter provided in an embodiment of the present application;

[0023] Figure 7 A schematic diagram of the structure of an optional electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0025] The present application provides an overcurrent protection circuit. Figure 1 A schematic diagram of an optional overcurrent protection circuit provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the overcurrent protection circuit 1000 is used to perform overcurrent protection on the DC-DC converter 111, including:

[0026] A current detection resistor 101, a first comparator 102, a second comparator 103, a first switch 104, a second switch 105, a third switch 106, a processor 107, a level conversion circuit 108, a voltage divider resistor 109 and a power supply 110, an output end of a DC-DC converter 111 is connected to one end of the current detection resistor 101, one end of the first switch 104 is respectively connected to the input end of the first comparator 102 and the other end of the current detection resistor 101, the other end of the first switch 104 is respectively connected to the power supply end of the load device 112 and one end of the second switch 105, and the other end of the second switch 105 is respectively connected to one end of the voltage divider resistor 109 and the third switch The first comparator 102 is connected to the input end of the level conversion circuit 108 and the first end of the processor 107 respectively, the output end of the level conversion circuit 108 is connected to the enable end of the DC-DC converter 111, the output end of the second comparator 103 is connected to the second end of the processor 107, the third end of the processor 107 is connected to the control end of the second switch 105 and the control end of the third switch 106 respectively, the processor 107 is also connected to the control end of the first switch 104, and the other end of the voltage divider resistor 109 is grounded through the power supply 110; wherein the processor 107 is used to:

[0027] When the overvoltage protection circuit 1000 is in the overcurrent protection state and the first output level of the second comparator 103 is the first indication level, the control end of the first switch 104, the control end of the second switch 105 and the control end of the third switch 106 are controlled so that the DC-DC converter 111 enters the power supply state for the load device 112;

[0028] Among them, the first indication level is used to indicate that the input voltage of the second comparator 103 is greater than the reference voltage of the second comparator 103; the overcurrent protection state is the state of the overcurrent protection circuit 1000 when the first switch 104 is turned off, the second switch 105 is closed, and the third switch 106 is closed; the power supply state is the state of the DC-DC converter 111 being turned on when the first switch 104 is closed, the second switch 105 is turned off, and the third switch 106 is turned off.

[0029] Figure 2a Schematic diagram of the overcurrent protection mechanism of the DC-DC converter in the related art Figure 1 ,like Figure 2a As shown, the overcurrent protection mechanism may include:

[0030] S201: Turning on the DC-DC converter, and the DC-DC converter outputs a target voltage;

[0031] S202: Determine whether an over current (OC) event occurs;

[0032] S203: If yes, turn off the output of the DC-DC converter.

[0033] Here, by detecting that the current in the path of the DC-DC converter exceeds the threshold, and when the threshold is exceeded, the DC-DC converter output will be turned off. However, with this method, after the path is restored, the circuit cannot be supplied by the DC-DC converter, that is, it cannot work normally.

[0034] Figure 2b FIG. 2 is a flow chart of an overcurrent protection mechanism of a DC-DC converter in the related art. Figure 2b As shown, the overcurrent protection mechanism may include:

[0035] S204: Turn on the DC-DC converter to output the target voltage;

[0036] S205: The detection circuit determines whether an overcurrent event occurs; if yes, execute S206;

[0037] S206: The anti-shake mechanism (detecting OC duration) determines whether an over-current protection (OCP) event is satisfied; if yes, execute S207;

[0038] S207: Turn off the DC-DC converter output and enter the hiccup protection mechanism (the DC-DC converter shutdown time can be set);

[0039] S208: Turn on the DC-DC converter (detect voltage) to determine whether there is an OC event; if yes, execute S206; if no, execute S204.

[0040] The hiccup mechanism is as follows: after entering the OCP mechanism, the output will be turned off for a period of time, and then the DC-DC converter will be turned on (the DC-DC converter can be set) to determine whether there is an OC event in the path. If there is still an OC event, the output will continue to be turned off. After the set time, the DC-DC converter will be turned on again to check whether there is still an OC event. If there is no OC event, the OCP protection mechanism will be exited and the normal output voltage will be output. If there is still an OC event, the above actions will be repeated until the OC event ends. However, with this method, in the case of abnormal load device scenarios (the power supply voltage (VCC, Volt Current Condenser) of the load device has a very small resistance to ground), when the DC-DC converter is turned on to determine whether there is still an OC event, there will still be a certain period of voltage output, and a large current will be generated at this time, so there is a risk of damaging the DC-DC converter.

[0041] In order to improve the reliability of the DC-DC converter 111, an embodiment of the present application provides an overcurrent protection circuit 1000, which is used to perform overcurrent protection on the DC-DC converter 111. For the overcurrent protection circuit 1000 in the overcurrent protection state, in order to promptly and accurately restore the power supply to the load device 112 when there is no overcurrent in the DC-DC converter 111, when the overcurrent protection circuit 1000 is in the overcurrent protection state, the output level of the second comparator 103 can be used to know whether the power supply voltage at the power supply end of the load device 112 is abnormal to the ground. If it is normal, it means that there is no risk of overcurrent in the DC-DC converter 111 at this time, so the power supply to the load device 112 is restored.

[0042] In order to restore the power supply to the load device 112, here, when the overcurrent protection circuit 1000 is in the overcurrent protection state, the first output level of the second comparator 103 is the first indication level, wherein the first indication level is used to indicate that the input voltage of the second comparator 103 is greater than the reference voltage of the second comparator 103; that is, when the overcurrent protection circuit 1000 is in the overcurrent protection state, and the first output level of the second comparator 103 indicates that the input voltage of the second comparator 103 is greater than the reference voltage of the second comparator 103, it means that at this time, the power supply voltage of the power supply end of the load device 113 is normal to the ground, and there is no risk of overcurrent when the DC-DC converter 111 supplies power to the load device 112. Therefore, at this time, the processor 107 switches from the overcurrent protection state of the overcurrent protection circuit 1000 to the power supply state of the DC-DC converter 111 by controlling the control end of the first switch 104, the control end of the second switch 105 and the control end of the third switch 106.

[0043] It should be noted that, when the processor 107 determines that the overcurrent protection circuit 1000 is in the overcurrent protection state, the state of the overcurrent protection circuit 1000 can be determined by the states of the first switch 104, the second switch 105 and the third switch 106, or by the value of the overcurrent protection flag (Over Current Protection flag, OCP flag) set in the processor 107. Here, the embodiment of the present application does not make specific limitations on this.

[0044] The load device 112 may be a power amplifier (PA) or other load devices, which is not specifically limited in the embodiment of the present application.

[0045] Among them, in the state of the overcurrent protection circuit 1000 and the DC-DC converter 111 being determined by the states of the first switch 104, the second switch 105 and the third switch 106, when the first switch 104 is turned off, the second switch 105 is closed, and the third switch 106 is closed, it is determined that the overcurrent protection circuit 1000 is in the overcurrent protection state, and when the first switch 104 is closed, the second switch 105 is turned off, and the third switch 106 is turned off, it is determined that the DC-DC converter 111 is in the power supply state.

[0046] When determining the states of the overcurrent protection circuit 1000 and the DC-DC converter 111 by the value of the OCP flag, in an optional embodiment, the processor is further configured to:

[0047] When the acquired OCP flag is the first preset threshold, it is determined that the overcurrent protection circuit 1000 is in the overcurrent protection state;

[0048] When the OCP flag is the second preset threshold, it is determined that the DC-DC converter 111 is in the power supply state.

[0049] It can be understood that when the OCP flag is a first preset threshold, the overcurrent protection circuit 1000 is in an overcurrent protection state, and when the OCP flag is a second preset threshold, the DC-DC converter 111 is in a power supply state, wherein the first preset threshold is different from the second preset threshold; that is, by setting the OCP flag in the processor 107, the processor 107 can obtain the states of the overcurrent protection circuit 1000 and the DC-DC converter 111, so that the processor 107 can quickly know whether the DC-DC converter 111 supplies power to the load device 112.

[0050] In addition, the processor 107 determines whether the DC-DC converter 111 supplies power to the load device 112 through the OCP flag. In order to know the state of the DC-DC converter 111, it is necessary to first determine the value of the OCP flag. In order to determine the value of the OCP flag, in an optional embodiment, the processor 107 is further configured to:

[0051] When the first switch 104 is closed, the second switch 105 is closed, and the third switch 106 is closed, a second output level of the first comparator 102 is obtained;

[0052] When the second output level is the invalid level of the enable signal of the DC-DC converter 111, the first switch 104 is kept closed, the second switch 105 is turned off, and the third switch 106 is turned off, and the OCP flag is set to the second preset threshold;

[0053] When the second output level is the effective level of the enable signal of the DC-DC converter 111, the control end of the first switch 104, the control end of the second switch 105 and the control end of the third switch 106 are controlled to turn off the first switch 104, close the second switch 105 and close the third switch 106, and set the OCP flag to the first preset threshold.

[0054] It can be understood that when the DC-DC converter 111 is in a normal working state, the first switch 104 is closed, the second switch 105 is turned off, and the third switch 106 is turned off. At this time, it is mainly through the output level of the first comparator 102, that is, the second output level, to determine whether there is an overcurrent in the path of the DC-DC converter 111. Therefore, at this time, the processor 107 obtains the second output level and determines whether the second output level is an invalid level of the enable signal of the DC-DC converter 111 or a valid level of the enable signal of the DC-DC converter 111.

[0055] By judging and determining that the second output level is the invalid level of the enable signal of the DC-DC converter 111, the level conversion circuit 108 converts the received invalid level into a valid level, so that the DC-DC converter 111 works normally, the first switch 104 remains closed, the second switch 105 remains turned off, the third switch 106 remains turned off, and the processor 107 sets the value of the OCP flag to the second preset threshold value, that is, the processor 107 determines that there is no overcurrent in the DC-DC converter 111 and is still in the power supply state of the DC-DC converter 111.

[0056] By judging and determining that the second output level is the effective level of the enable signal of the DC-DC converter 111, the level conversion circuit 108 converts the received effective level to an invalid level, so that the DC-DC converter 111 does not work, and controls the control end of the first switch 104, the control end of the second switch 105 and the control end of the third switch 106, so that the first switch 104 is turned off, the second switch 105 is closed, and the third switch 106 is closed, and the processor 107 sets the value of the OCP flag to the first preset threshold value, that is, the processor 107 determines that there is an overcurrent in the DC-DC converter 111, and switches the DC-DC converter 111 from the power supply state to the overcurrent protection state of the overcurrent protection circuit 1000.

[0057] Since the processor 107 can be directly connected to the first switch 104 or connected to the first switch 104 through the level conversion circuit 108, then, for the case where the processor 107 is directly connected to the first switch 104, in order to switch the overcurrent protection state of the overcurrent protection circuit 1000 to the power supply state of the DC-DC converter 111, in an optional embodiment, the third terminal of the processor 107 is connected to the control terminal of the first switch 104; wherein,

[0058] The processor 107 controls the control end of the first switch 104, the control end of the second switch 105, and the control end of the third switch 106 to enable the DC-DC converter 111 to enter a power supply state for the load device 112, including:

[0059] The control end of the first switch 104 , the control end of the second switch 105 and the control end of the third switch 106 are controlled to close the first switch 104 , turn off the second switch 105 and turn off the third switch 106 .

[0060] It can be understood that the processor 107 directly controls the control end of the first switch 104, the control end of the second switch 105 and the control end of the third switch 106, so that the first switch 104 is closed, the second switch 105 is turned off and the third switch 106 is turned off, so that the DC-DC converter 111 supplies power to the load device 112.

[0061] In addition, if the value of the OCP flag is used to determine the state of the DC-DC converter 111 , the OCP flag is also set to the second preset threshold value, so that the processor 107 can determine the state of the DC-DC converter 111 .

[0062] In addition, for the DC-DC converter 111 when the overcurrent protection circuit 1000 is in the overcurrent protection state, in an optional embodiment, the processor 107 is further configured to:

[0063] When the overcurrent protection circuit 1000 is in the overcurrent protection state and the first output level is the second indication level, the control end of the first switch 104, the control end of the second switch 105 and the control end of the third switch 106 are controlled so that the overcurrent protection circuit 1000 remains in the overcurrent protection state.

[0064] It can be understood that when the overcurrent protection circuit 1000 is in the overcurrent protection state and the first output level is the second indication level, wherein the second indication level is used to indicate that the input voltage of the second comparator 103 is less than the reference voltage of the second comparator 103; that is, when the overcurrent protection circuit 1000 is in the overcurrent protection state, and the first output level indicates that the input voltage of the second comparator 103 is less than the reference voltage of the second comparator 103, it means that at this time, the power supply voltage at the power supply end of the load device 112 is abnormal to the ground, and there is a risk of overcurrent when the DC-DC converter 111 supplies power to the load device 112. Therefore, at this time, the processor 107 controls the control end of the first switch 104, the control end of the second switch 105 and the control end of the third switch 106 so that the overcurrent protection circuit 1000 continues to be in the overcurrent protection state to protect the DC-DC converter 111 from damage.

[0065] In order to keep the overcurrent protection circuit 1000 in the overcurrent protection state, in an optional embodiment, the third terminal of the processor 107 is connected to the control terminal of the first switch 104; wherein,

[0066] The processor 107 controls the control end of the first switch 104, the control end of the second switch 105, and the control end of the third switch 106 to keep the overcurrent protection circuit 1000 in the overcurrent protection state, including:

[0067] The control end of the first switch 104 , the control end of the second switch 105 and the control end of the third switch 106 are controlled to turn off the first switch 104 , turn on the second switch 105 and turn on the third switch 106 .

[0068] It can be understood that since the third end of the processor 107 is directly connected to the control end of the first switch 104, the control end of the first switch 104 can be directly controlled. Therefore, here, the processor 107 directly controls the control end of the first switch 104, the control end of the second switch 105 and the control end of the third switch 106, thereby turning off the first switch 104, closing the second switch 105 and closing the third switch 106, so that the overcurrent protection circuit 1000 is in the overcurrent protection state.

[0069] With respect to the structure in which the first terminal of the processor 107 is connected to the control terminal of the first switch 104 via the level conversion circuit 108, in order to enable the DC-DC converter 111 to enter a power supply state for the load device 112, in an optional embodiment, the control terminal of the first switch 104 is connected to the first terminal of the processor 107 via the output terminal of the level conversion circuit 108; wherein,

[0070] The processor 107 controls the control end of the first switch 104, the control end of the second switch 105, and the control end of the third switch 106 to enable the DC-DC converter 111 to enter a power supply state for the load device 112, including:

[0071] The invalid level of the enable signal of the DC-DC converter 111 is output to the level conversion circuit 108 to close the first switch 104, and the control end of the first switch 104, the control end of the second switch 105 and the control end of the third switch 106 are controlled to close the first switch 104, turn off the second switch 105 and turn off the third switch 106.

[0072] It can be understood that since the control end of the first switch 104 is connected to the output end of the level conversion circuit 108, in order to enable the DC-DC converter 111 to enter the power supply state for the load device 112, the DC-DC converter 111 needs to work and close the first switch 104. Therefore, the processor 107 outputs the invalid level of the enable signal of the DC-DC converter 111 to the level conversion circuit 108, and the level conversion circuit 108 converts the invalid level to obtain a valid level. The valid level can close the first switch on the one hand, and enable the DC-DC converter 111 to work normally on the other hand. At the same time, the processor 107 directly controls the control end of the second switch 105 and the control end of the third switch 106 to turn off the second switch 105 and turn off the third switch 106.

[0073] In this way, the processor 107 controls the second switch 105 and the third switch 106 directly, and controls the first switch 104 and the DC-DC converter 111 by controlling the level conversion circuit 108 , so that the DC-DC converter 111 is in a power supply state for the load device 112 .

[0074] In addition, based on the structure that the first end of the processor 107 is connected to the control end of the first switch 104 through the level conversion circuit 108, in order to maintain the overcurrent protection circuit 1000 in the overcurrent protection state, in an optional embodiment, the control end of the first switch 104 is connected to the first end of the processor 107 by connecting the output end of the level conversion circuit 108; wherein,

[0075] The processor 107 controls the control end of the first switch 104, the control end of the second switch 105, and the control end of the third switch 106 to keep the overcurrent protection circuit 1000 in the overcurrent protection state, including:

[0076] The active level of the enable signal of the DC-DC converter 111 is output to the level conversion circuit 108 to keep the first switch 104 open, the second switch 105 closed, and the third switch 106 closed.

[0077] It can be understood that since the control end of the first switch 104 is connected to the output end of the level conversion circuit 108, in order to maintain the overcurrent protection circuit 1000 in the overcurrent protection state, the DC-DC converter 111 needs to be non-operating and the first switch 104 continues to be disconnected. Therefore, the processor 107 outputs the effective level of the enable signal of the DC-DC converter 111 to the level conversion circuit 108, and the level conversion circuit 108 converts the effective level to obtain an invalid level. The invalid level can turn off the first switch on the one hand, and make the DC-DC converter 111 non-operating on the other hand. At the same time, the processor 107 directly controls the control end of the second switch 105 and the control end of the third switch 106 to close the second switch 105 and close the third switch 106.

[0078] In this way, the processor 107 controls the second switch 105 and the third switch 106 directly, and controls the first switch 104 and the DC-DC converter 111 by controlling the level conversion circuit 108, so that the overcurrent protection circuit 1000 is maintained in the overcurrent protection state.

[0079] In order to further improve the reliability of the DC-DC converter 111, it is necessary to further screen the output level of the first comparator 102 to prevent the temporary output from affecting the reliability of the DC-DC converter 111. In an optional embodiment, the circuit further includes: a first anti-shake circuit; wherein,

[0080] The first anti-shake circuit is arranged at the output end of the first comparator 102, between the first end of the processor 107 and the input end of the level conversion circuit 108, and the first anti-shake circuit is used to output the output level of the first comparator 102 that lasts for a preset time threshold to the processor 107 and the level conversion circuit 108 respectively, and the first anti-shake circuit is also used to output the output level of the processor 107 that lasts for a preset time threshold to the level conversion circuit 108.

[0081] It can be understood that a first anti-shake circuit is set between the output end of the first comparator 102, the first end of the processor 107 and the input end of the level conversion circuit 108, so that when the output level of the first comparator 102 is maintained at a preset time threshold, the first anti-shake circuit outputs the output level of the first comparator 102 to the processor and the level conversion circuit. Similarly, when the output level of the first end of the processor is maintained at a preset time threshold, the first anti-shake circuit outputs the output level of the first end of the processor 107 to the level conversion circuit 108; in this way, the influence of the jittered output level on the reliability of the DC-DC converter 111 can be avoided.

[0082] In order to further improve the reliability of the DC-DC converter 111, it is necessary to further screen the output level of the second comparator 103 to prevent the temporary output from affecting the reliability of the DC-DC converter 111. In an optional embodiment, the circuit further includes a second anti-shake circuit; wherein,

[0083] The second anti-shake circuit is disposed between the output end of the second comparator 103 and the processor 107 , and is used for outputting the output level of the second comparator 103 that lasts for a preset time threshold to the processor 107 .

[0084] It can be understood that a second anti-shake circuit is set between the output end of the second comparator 103 and the second end of the processor 107, so that when the output level of the second comparator 103 is maintained at a preset time threshold, the second anti-shake circuit outputs the output level of the second comparator 103 to the processor 107; in this way, the influence of the jittered output level on the reliability of the DC-DC converter 111 can be avoided.

[0085] It should be noted that the overcurrent protection circuit 1000 may be provided in the DC-DC converter 111 or may be provided independently of the DC-DC converter 111 . The embodiment of the present application does not specifically limit this.

[0086] The overcurrent protection circuit described in one or more of the above embodiments is described below with examples.

[0087] Figure 3 A structural diagram of an example 1 of an optional overcurrent protection circuit provided in an embodiment of the present application, such as Figure 3 As shown, the overcurrent protection circuit is used to perform overcurrent protection on the DC-DC converter 312. The DC-DC converter 312 is used to power PA314. The power supply terminal VCC of PA314 is connected to the output terminal of the DC-DC converter 312 through the current detection resistor Rs313. The equivalent resistance of PA314 to the ground is RL.

[0088] Figure 3The overcurrent protection circuit is arranged in the DC-DC converter 312, and the overcurrent protection circuit includes: a comparator 301, a comparator 302, an anti-shake circuit 303, an anti-shake circuit 304, a processor 305, a level conversion circuit 306, a voltage divider resistor R307, a DC power supply 308, a switch 309, a switch 310, a switch 311 and a current detection resistor 313; wherein, the input end of the comparator 301 is connected to the connection node of Rs313 and the switch 309, the output end of the comparator 301 is connected to the input end of the anti-shake circuit 303, the output end of the anti-shake circuit 303 is respectively connected to the pin1 of the level conversion circuit 306 and the processor 305, and the output end of the level conversion circuit 306 is respectively connected to the DC-DC converter The enable end of switch 312 and the control end of switch 309, pin3 of processor 305 are respectively connected to the control end of switch 310 and the control end of switch 311, one end of switch 310 is connected to the connection node of switch 309 and PA314, the other end of switch 310 is connected to one end of voltage-dividing resistor R307, the other end of voltage-dividing resistor R307 is connected to the positive electrode of DC power supply 308, the negative electrode of DC power supply 308 is grounded, one end of switch 311 is connected to the connection node of switch 310 and voltage-dividing resistor R307, the other end of switch 311 is connected to the input end of comparator 302, the output end of comparator 302 is connected to the input end of anti-shake circuit 304, and the output end of anti-shake circuit 304 is connected to pin2 of processor 305.

[0089] Based on the above Figure 3 , divided into two situations, one is the normal state and the other is the abnormal state;

[0090] For the first case: normal state, that is, PA314 is normal and the value of RL is normal;

[0091] In the normal state, the DC-DC converter 312 outputs normally, there is no overcurrent on Rs313, Rs313 converts the current into voltage as the input voltage of the comparator 301, and compares it with the reference voltage 1 of the comparator 301. When the input voltage is greater than the reference voltage 1, the comparator 301 outputs a low level; the anti-shake circuit 303 outputs a low level when the preset time threshold is met, and the level conversion circuit 306 converts the low level to a high level, the enable end of the DC-DC converter 312 receives a valid level, and the DC-DC converter 312 works normally.

[0092] In addition, when the anti-shake circuit 303 outputs a low level, the OCP Flag in the processor 305 is set to 0, and a low level is output to turn off the switch 310 and the switch 311. At this time, the input voltage of the comparator 302 is 0, which is less than the reference voltage 2 of the comparator 302. The comparator 302 outputs a low level, and the anti-shake circuit 304 outputs a low level to pin2 of the processor 305. After pin2 of the processor 305 receives the low level, pin1 and pin3 of the processor 305 still output a low level to keep the circuit working normally.

[0093] The second situation: abnormal state, that is, the VCC of PA314 is abnormal, and the ground resistance RL of PA314 becomes smaller;

[0094] When there is an overcurrent on Rs313, V / RL=I, I becomes larger, and the voltage is converted by Rs313, so that the input voltage of the comparator 301 is less than the reference voltage 1 of the comparator 301, and the comparator 301 outputs a high level. When the duration of the high level exceeds the preset time threshold, the anti-shake circuit 303 outputs a high level, and the level conversion circuit 306 converts the high level into a low level and outputs it to the enable end of the DC-DC converter 312, so that the DC-DC converter 312 is turned off, and the switch 309 is turned off. At this time, the pin1 of the processor 305 inputs a high level, and the processor 305 sets the OCP Flag to 1, indicating that the circuit has an overcurrent, and the pin3 of the processor 305 outputs a high level, so that the switch 310 is closed and the switch 311 is closed.

[0095] In this way, the voltage-dividing resistor R307 and RL divide the voltage. Since RL is small, the input voltage of the comparator 302 is less than the reference voltage 2, and the comparator 302 outputs a low level. After the anti-shake time is satisfied, the anti-shake circuit 304 outputs a low level. When pin2 of the processor 305 receives a low level and the OCP Flag is 1, pin1 of the processor 305 outputs a high level, and pin3 outputs a high level, keeping the output of the DC-DC converter 312 off, the switch 310 and the switch 311 closed, and the comparator 302 and the anti-shake circuit 304 work normally.

[0096] Assuming that VCC of PA314 returns to normal, RL returns to normal, and the voltage obtained by voltage-dividing resistor R307 and RL is divided, and the voltage obtained by RL voltage division is higher than reference voltage 2, comparator 302 outputs a high level, and after the anti-shake time is satisfied, the anti-shake circuit 304 outputs a high level; when pin2 of processor 305 receives a high level and OCP Flag is 1, pin1 outputs a low level, pin3 outputs a low level, the DC-DC converter 312 and switch 309 are closed, switches 310 and 311 are turned off, and the circuit works normally.

[0097] In this way, without starting the DC-DC converter 312 , the voltage is detected by the circuit to determine whether the load resistance RL of the VCC of the PA 314 is too small, thereby protecting the DC-DC converter 312 .

[0098] In this example, without turning on the DC-DC converter 312, it can be determined whether the load resistance RL of the VCC of the PA 314 is too small, resulting in a large current, thereby protecting the internal circuit of the DC-DC converter 312 from being burned out.

[0099] Figure 4 A structural diagram of an optional overcurrent protection circuit according to an embodiment of the present application is shown in FIG. Figure 4 As shown, Figure 3 The devices and connection structures are the same, except that the overcurrent protection circuit (circuit in the dotted box) is set independently of the DC-DC converter.

[0100] That is to say, in the above example, without turning on the DC-DC converter, the voltage divider resistor, comparator, switch, and anti-shake circuit are used to determine whether the load resistance is normal. Therefore, only the detection circuit can be used to determine whether an overcurrent event will occur, thereby protecting the internal circuit of the DC-DC converter from damage.

[0101] The embodiment of the present application provides an overcurrent protection circuit, which is used to perform overcurrent protection on a DC-DC converter, including: a current detection resistor, a first comparator, a second comparator, a first switch, a second switch, a third switch, a processor, a level conversion circuit, a voltage divider resistor, a power supply, the output end of the DC-DC converter is connected to one end of the current detection resistor, one end of the first switch is respectively connected to the input end of the first comparator and the other end of the current detection resistor, the other end of the first switch is respectively connected to the power supply end of the load device and one end of the second switch, the other end of the second switch is respectively connected to one end of the voltage divider resistor and one end of the third switch, the other end of the third switch is connected to the input end of the second comparator, the output end of the first comparator is respectively connected to the input end of the level conversion circuit and the first end of the processor, the output end of the level conversion circuit is connected to the enable end of the DC-DC converter, the output end of the second comparator is connected to the second end of the processor, the third end of the processor is respectively connected to the control end of the second switch and the control end of the third switch, the processor is also connected to the control end of the first switch, and the other end of the voltage divider resistor is grounded through the power supply, and the processor is used to: when the overcurrent protection state is in the overcurrent protection state When the overcurrent protection state is reached and the first output level of the second comparator is the first indication level, the control end of the first switch, the control end of the second switch and the control end of the third switch are controlled so that the DC-DC converter enters the power supply state for the load device; wherein the first indication level is used to indicate that the input voltage of the second comparator is greater than the reference voltage of the second comparator; that is, by providing an overcurrent protection circuit for the DC-DC converter, when the overcurrent protection circuit performs overcurrent protection on the DC-DC converter, it can be determined whether the input voltage of the second comparator is greater than the reference voltage of the second comparator through the first output level of the second comparator. If greater than, it indicates that the power supply end abnormality of the load device no longer exists, so there is no overcurrent at the output end of the DC-DC converter. At this time, the processor controls the first switch, the second switch and the third switch to switch from the overcurrent protection state of the overcurrent protection circuit to the power supply state of the DC-DC converter for the load device, thereby avoiding the risk of damage to the DC-DC converter caused by the overcurrent switching to the power supply state, so that the DC-DC converter can be powered on in a timely and safe manner, thereby improving the reliability of the DC-DC converter.

[0102] Based on the same inventive concept, an embodiment of the present application provides a control method, which is applied to a processor of an overcurrent protection circuit as described in one or more of the above embodiments. Figure 5 A flow chart of an optional control method provided in an embodiment of the present application is as follows: Figure 5 As shown, the method includes:

[0103] S501: When the overcurrent protection circuit is in the overcurrent protection state and the first output levels of the second comparator are all the first indication level, the control end of the first switch, the control end of the second switch and the control end of the third switch are controlled so that the DC-DC converter enters the power supply state for the load device.

[0104] Among them, the first indication level is used to indicate that the input voltage of the second comparator is greater than the reference voltage of the second comparator; the overcurrent protection state is the state of the overcurrent protection circuit when the first switch is turned off, the second switch is closed, and the third switch is closed; the power supply state is the state of the DC-DC converter being turned on when the first switch is closed, the second switch is turned off, and the third switch is turned off.

[0105] In an optional embodiment, the above method further includes:

[0106] When the acquired OCP flag is a first preset threshold, determining that the overcurrent protection circuit is in an overcurrent protection state;

[0107] When the OCP flag is a second preset threshold, determining that the DC-DC converter is in a power supply state;

[0108] The first preset threshold is different from the second preset threshold.

[0109] In an optional embodiment, when the first switch is closed, the second switch is turned off, and the third switch is turned off, a second output level of the first comparator is obtained;

[0110] When the second output level is an invalid level of the enable signal of the DC-DC converter, the first switch is kept closed, the second switch is turned off, and the third switch is turned off, and the OCP flag is set to a second preset threshold;

[0111] When the second output level is the effective level of the enable signal of the DC-DC converter, the control end of the first switch, the control end of the second switch and the control end of the third switch are controlled to turn off the first switch, close the second switch and close the third switch, and set the OCP flag to a first preset threshold.

[0112] In an optional embodiment, controlling the control end of the first switch, the control end of the second switch, and the control end of the third switch so that the DC-DC converter enters a state of supplying power to a load device includes:

[0113] The control end of the first switch, the control end of the second switch and the control end of the third switch are controlled to close the first switch, turn off the second switch and turn off the third switch.

[0114] In an optional embodiment, the method further includes:

[0115] When the overcurrent protection circuit is in the overcurrent protection state and the first output level is the second indication level, the control end of the first switch, the control end of the second switch and the control end of the third switch are controlled so that the overcurrent protection circuit remains in the overcurrent protection state;

[0116] The second indication level is used to indicate that the input voltage of the second comparator is less than the reference voltage of the second comparator.

[0117] In an optional embodiment, controlling the control end of the first switch, the control end of the second switch, and the control end of the third switch so that the overcurrent protection circuit remains in the overcurrent protection state includes:

[0118] The control end of the first switch, the control end of the second switch and the control end of the third switch are controlled to turn off the first switch, close the second switch and close the third switch.

[0119] In an optional embodiment, controlling the control end of the first switch, the control end of the second switch, and the control end of the third switch so that the DC-DC converter enters a state of supplying power to a load device includes:

[0120] The inactive level of the enable signal of the DC-DC converter is output to the level conversion circuit to close the first switch, and the control terminal of the second switch and the control terminal of the third switch are controlled to turn off the second switch and turn off the third switch.

[0121] In an optional embodiment, controlling the control end of the first switch, the control end of the second switch, and the control end of the third switch so that the overcurrent protection circuit remains in the overcurrent protection state includes:

[0122] The active level of the enable signal of the DC-DC converter is output to the level conversion circuit to keep the first switch open, the second switch closed, and the third switch closed.

[0123] Figure 6 A schematic diagram of the structure of an optional DC-DC converter provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the DC-DC converter 600 includes the overcurrent protection circuit 61 described in one or more of the above embodiments.

[0124] Figure 7 A schematic diagram of the structure of an optional electronic device provided in an embodiment of the present application, such as Figure 7As shown, an embodiment of the present application provides an electronic device 700, comprising: a DC-DC converter 71 as described in one or more of the above embodiments and a storage medium 72 storing executable instructions of the processor 711; the storage medium 72 relies on the processor 711 to perform operations through a communication bus 73, and when the instructions are executed by the processor 711, the control method described in one or more of the above embodiments is executed.

[0125] It should be noted that in actual application, the various components in the terminal are coupled together through the communication bus 73. It is understandable that the communication bus 73 is used to realize the connection and communication between these components. In addition to the data bus, the communication bus 73 also includes a power bus, a control bus and a status signal bus. However, for the sake of clarity, Figure 7 Various buses are labeled as communication buses 73.

[0126] An embodiment of the present application provides a computer storage medium storing executable instructions. When the executable instructions are executed by one or more processors, the processors execute the control method described in one or more of the above embodiments.

[0127] Among them, the computer-readable storage medium can be a ferromagnetic random access memory (FRAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a magnetic surface memory, an optical disk, or a compact disc read-only memory (CD-ROM) and other memories.

[0128] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of hardware embodiments, software embodiments, or embodiments in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0129] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0130] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0131] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0132] The above description is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application.

Claims

1. An overcurrent protection circuit, characterized in that: The overcurrent protection circuit is used to perform overcurrent protection on a DC-DC converter, and includes: a current detection resistor, a first comparator, a second comparator, a first switch, a second switch, a third switch, a processor, a level conversion circuit, a voltage divider resistor and a power supply, wherein the output end of the DC-DC converter is connected to one end of the current detection resistor, one end of the first switch is respectively connected to the input end of the first comparator and the other end of the current detection resistor, the other end of the first switch is respectively connected to the power supply end of the load device and one end of the second switch, the other end of the second switch is respectively connected to one end of the voltage divider resistor and one end of the third switch, the other end of the third switch is connected to the input end of the second comparator, the output end of the first comparator is respectively connected to the input end of the level conversion circuit and the first end of the processor, the output end of the level conversion circuit is connected to the enable end of the DC-DC converter, the output end of the second comparator is connected to the second end of the processor, the third end of the processor is respectively connected to the control end of the second switch and the control end of the third switch, the processor is also connected to the control end of the first switch, and the other end of the voltage divider resistor is grounded through the power supply; wherein the processor is used to: When the overcurrent protection circuit is in the overcurrent protection state and the first output level of the second comparator is the first indication level, controlling the control end of the first switch, the control end of the second switch and the control end of the third switch so that the DC-DC converter enters a power supply state for the load device; Among them, the first indication level is used to indicate that the input voltage of the second comparator is greater than the reference voltage of the second comparator; the overcurrent protection state is the state of the overcurrent protection circuit when the first switch is turned off, the second switch is closed, and the third switch is closed; the power supply state is the state of the DC-DC converter being turned on when the first switch is closed, the second switch is turned off, and the third switch is turned off.

2. The circuit according to claim 1, characterized in that The processor is further configured to: When the acquired OCP flag is a first preset threshold, determining that the overcurrent protection circuit is in the overcurrent protection state; When the OCP flag is a second preset threshold, determining that the DC-DC converter is in the power supply state; Wherein, the first preset threshold value is different from the second preset threshold value; The OCP flag is an over-current protection flag.

3. The circuit according to claim 2, characterized in that The processor is further configured to: When the first switch is closed, the second switch is turned off, and the third switch is turned off, obtaining a second output level of the first comparator; When the second output level is an invalid level of the enable signal of the DC-DC converter, keep the first switch closed, turn off the second switch and turn off the third switch, and set the OCP flag to the second preset threshold; When the second output level is the effective level of the enable signal of the DC-DC converter, the control end of the first switch, the control end of the second switch and the control end of the third switch are controlled to turn off the first switch, close the second switch and close the third switch, and set the OCP flag to the first preset threshold.

4. The circuit according to any one of claims 1 to 3, characterized in that: The third terminal of the processor is connected to the control terminal of the first switch; wherein, The processor controls the control end of the first switch, the control end of the second switch, and the control end of the third switch so that the DC-DC converter enters a state of supplying power to the load device, including: The control end of the first switch, the control end of the second switch and the control end of the third switch are controlled to close the first switch, turn off the second switch and turn off the third switch.

5. The circuit according to any one of claims 1 to 3, characterized in that: The processor is further configured to: When the overcurrent protection circuit is in the overcurrent protection state and the first output level is a second indication level, controlling the control end of the first switch, the control end of the second switch and the control end of the third switch so that the overcurrent protection circuit remains in the overcurrent protection state; The second indication level is used to indicate that the input voltage of the second comparator is less than the reference voltage of the second comparator.

6. The circuit according to claim 5, characterized in that The third terminal of the processor is connected to the control terminal of the first switch; wherein, The processor controls the control end of the first switch, the control end of the second switch, and the control end of the third switch so that the overcurrent protection circuit remains in the overcurrent protection state, including: The control end of the first switch, the control end of the second switch and the control end of the third switch are controlled to turn off the first switch, turn on the second switch and turn on the third switch.

7. The circuit according to any one of claims 1 to 3, characterized in that: The control end of the first switch is connected to the first end of the processor by connecting the output end of the level conversion circuit; wherein, The processor controls the control end of the first switch, the control end of the second switch, and the control end of the third switch so that the DC-DC converter enters a state of supplying power to the load device, including: The inactive level of the enable signal of the DC-DC converter is output to the level conversion circuit to close the first switch, and the control terminal of the second switch and the control terminal of the third switch are controlled to turn off the second switch and turn off the third switch.

8. The circuit according to claim 5, characterized in that The control end of the first switch is connected to the first end of the processor by connecting the output end of the level conversion circuit; wherein, The processor controls the control end of the first switch, the control end of the second switch, and the control end of the third switch so that the overcurrent protection circuit remains in the overcurrent protection state, including: The active level of the enable signal of the DC-DC converter is output to the level conversion circuit to keep the first switch open, the second switch closed, and the third switch closed.

9. The circuit according to any one of claims 1 to 3, characterized in that: The circuit further includes: a first anti-shake circuit; wherein, The first anti-shake circuit is arranged at the output end of the first comparator, between the first end of the processor and the input end of the level conversion circuit, and the first anti-shake circuit is used to output the output level of the first comparator that lasts for a preset time threshold to the processor and the level conversion circuit respectively, and the first anti-shake circuit is also used to output the output level of the processor that lasts for a preset time threshold to the level conversion circuit.

10. The circuit according to any one of claims 1 to 3, characterized in that: The circuit also includes a second anti-shake circuit; wherein, The second anti-shake circuit is arranged between the output end of the second comparator and the processor, and the second anti-shake circuit is used to output the output level of the second comparator that lasts for a preset time threshold to the processor.

11. A control method, characterized in that: The method is applied to a processor of the overcurrent protection circuit according to any one of claims 1 to 10, comprising: When the overcurrent protection circuit is in the overcurrent protection state and the first output level of the second comparator is the first indication level, controlling the control end of the first switch, the control end of the second switch and the control end of the third switch so that the DC-DC converter enters a power supply state for the load device; Among them, the first indication level is used to indicate that the input voltage of the second comparator is greater than the reference voltage of the second comparator; the overcurrent protection state is the state of the overcurrent protection circuit when the first switch is turned off, the second switch is closed, and the third switch is closed; the power supply state is the state of the DC-DC converter being turned on when the first switch is closed, the second switch is turned off, and the third switch is turned off.

12. The method according to claim 11, characterized in that The method further comprises: When the acquired OCP flag is a first preset threshold, determining that the overcurrent protection circuit is in the overcurrent protection state; When the OCP flag is a second preset threshold, determining that the DC-DC converter is in the power supply state; Wherein, the first preset threshold value is different from the second preset threshold value; The OCP flag is an over-current protection flag.

13. The method according to claim 12, characterized in that The method further comprises: When the first switch is closed, the second switch is turned off, and the third switch is turned off, obtaining a second output level of the first comparator; When the second output level is an invalid level of the enable signal of the DC-DC converter, keep the first switch closed, turn off the second switch and turn off the third switch, and set the OCP flag to the second preset threshold; When the second output level is the effective level of the enable signal of the DC-DC converter, the control end of the first switch, the control end of the second switch and the control end of the third switch are controlled to turn off the first switch, close the second switch and close the third switch, and set the OCP flag to the first preset threshold.

14. The method according to any one of claims 11 to 13, characterized in that The controlling the control end of the first switch, the control end of the second switch and the control end of the third switch so that the DC-DC converter enters a state of supplying power to the load device comprises: The control end of the first switch, the control end of the second switch and the control end of the third switch are controlled to close the first switch, turn off the second switch and turn off the third switch.

15. The method according to any one of claims 11 to 13, characterized in that: The method further comprises: When the overcurrent protection circuit is in the overcurrent protection state and the first output level is a second indication level, controlling the control end of the first switch, the control end of the second switch and the control end of the third switch so that the overcurrent protection circuit remains in the overcurrent protection state; The second indication level is used to indicate that the input voltage of the second comparator is less than the reference voltage of the second comparator.

16. The method according to claim 15, characterized in that The controlling the control end of the first switch, the control end of the second switch, and the control end of the third switch so that the overcurrent protection circuit remains in the overcurrent protection state includes: The control end of the first switch, the control end of the second switch and the control end of the third switch are controlled to turn off the first switch, turn on the second switch and turn on the third switch.

17. The method according to any one of claims 11 to 13, characterized in that The controlling the control end of the first switch, the control end of the second switch and the control end of the third switch so that the DC-DC converter enters a state of supplying power to the load device comprises: The inactive level of the enable signal of the DC-DC converter is output to the level conversion circuit to close the first switch, and the control terminal of the second switch and the control terminal of the third switch are controlled to turn off the second switch and turn off the third switch.

18. The method according to claim 15, characterized in that The controlling the control end of the first switch, the control end of the second switch, and the control end of the third switch so that the overcurrent protection circuit remains in the overcurrent protection state includes: The active level of the enable signal of the DC-DC converter is output to the level conversion circuit to keep the first switch open, the second switch closed, and the third switch closed.

19. A DC-DC converter, characterized in that: The invention comprises an overcurrent protection circuit as claimed in any one of claims 1 to 10.

20. An electronic device, characterized in that: It comprises a DC-DC converter as described in claim 19 and a storage medium storing instructions executable by the processor; the storage medium relies on the processor to perform operations through a communication bus, and when the instructions are executed by the processor, the control method described in any one of claims 11 to 18 is executed.

21. A computer storage medium, characterized in that Executable instructions are stored, and when the executable instructions are executed by one or more processors, the processors execute the control method described in any one of claims 11 to 18.

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