Switching power supply protection circuit and electronic equipment based on forced continuous mode

Abstract

The present application provides a switching power supply protection circuit and electronic device based on a forced continuous mode, which belongs to the field of switching power supplies. The first input end of the pulse width modulation module is connected to the output end of the switching power supply. The second input end of the pulse width modulation module is connected to the current sampling end of the switching power supply. The pulse width modulation module outputs a pulse width modulation signal according to the output voltage signal and the current sampling signal. The signal end of the control module is connected to the output end of the pulse width modulation module. The control end of the control module is connected to the driving end of the switching power supply. When the input inductance energy of the switching power supply is greater than the output inductance energy, the control module controls the switching power supply to turn off the freewheeling tube according to the pulse width modulation signal and the clock signal. Through the circuit of the present application, the risk of damaging the chip due to excessive inductance negative current in the switching power supply can be avoided in the forced continuous mode, which solves the problem of excessive negative current in abnormal conditions in traditional switching power supplies.

Description

Technical Field

[0001] The present application belongs to the technical field of switching power supplies, and in particular, relates to a switching power supply protection circuit and electronic equipment based on a forced continuous mode. Background Art

[0002] In the light load state of the switching power supply system, the discontinuous working mode or the forced continuous working mode can be used. In the discontinuous working mode, the switching frequency changes with the output load, the output voltage ripple is large, and there is a large ringing noise at the switch node. Furthermore, in actual application scenarios, in order to stabilize the switching frequency, reduce the output voltage ripple, and reduce the ringing noise of the switch node, the forced continuous working mode is used.

[0003] In the forced continuous operation mode, current always flows through the inductor in each switching cycle. However, in the forced continuous operation mode, the inductor current in the switching power supply will have a large negative current under abnormal conditions, causing the chip to be destroyed. Summary of the invention

[0004] The purpose of the present application is to provide a switching power supply protection circuit and electronic equipment based on a forced continuous mode, aiming to solve the problem of large negative current in the inductor current in a traditional switching power supply.

[0005] The present application provides a switching power supply protection circuit based on a forced continuous mode, which is applied to a switching power supply. The switching power supply is used to convert an input voltage in a forced continuous mode to obtain an output voltage signal. The circuit includes:

[0006] A pulse width modulation module, wherein a first input terminal of the pulse width modulation module is connected to an output terminal of the switching power supply, a second input terminal of the pulse width modulation module is connected to a current sampling terminal of the switching power supply, and the pulse width modulation module is used to output a pulse width modulation signal according to the output voltage signal and the current sampling signal;

[0007] A regulation module, wherein the signal end of the regulation module is connected to the output end of the pulse width modulation module, the control end of the regulation module is connected to the driving end of the switching power supply, and the regulation module is used to regulate the freewheeling tube of the switching power supply to be turned off according to the pulse width modulation signal and the clock signal when the input inductance energy of the switching power supply is greater than the output inductance energy.

[0008] In one embodiment, the control module includes:

[0009] A first regulating submodule, wherein a first signal input terminal of the first regulating submodule is connected to an output terminal of the pulse width modulation module, a second signal input terminal of the first regulating submodule is used to obtain the clock signal, and a control terminal of the first regulating submodule is connected to a freewheeling tube driving terminal of the switching power supply;

[0010] a second regulating submodule, wherein the first signal input terminal of the second regulating submodule is connected to the output terminal of the pulse width modulation module, the second signal input terminal of the second regulating submodule is used to obtain the clock signal, the second signal input terminal of the second regulating submodule is also connected to the signal regulating terminal of the first regulating submodule, the signal regulating terminal of the second regulating submodule is connected to the third signal input terminal of the first regulating submodule, and the control terminal of the second regulating submodule is connected to the switch tube driving terminal of the switching power supply;

[0011] The first regulating submodule is used to regulate the conduction or shutdown of the freewheeling tube of the switching power supply according to the pulse width modulation signal, the clock signal and the regulating signal output by the signal regulating end of the second regulating submodule;

[0012] The second regulating submodule is used to regulate the switching tube of the switching power supply to be turned on or off according to the pulse width modulation signal, the clock signal and the regulating signal output by the signal regulating end of the first regulating submodule.

[0013] In one embodiment, the first regulation submodule comprises:

[0014] A first inverter, wherein an input terminal of the first inverter is connected to an output terminal of the pulse width modulation module;

[0015] a first trigger, wherein an input terminal of the first trigger is connected to an output terminal of the first inverter, and a clock terminal of the first trigger is used to obtain a clock signal;

[0016] A second inverter, wherein an input terminal of the second inverter is connected to an output terminal of the first trigger;

[0017] A first OR operator, wherein a first input terminal of the first OR operator is connected to an output terminal of the second inverter;

[0018] A first driver submodule, wherein the input end of the first driver submodule is connected to the output end of the first OR operator, and the output end of the first driver submodule is connected to the freewheeling tube driving end of the switching power supply.

[0019] In one embodiment, the second regulation submodule comprises:

[0020] A first AND operator, wherein a first input terminal of the first AND operator is connected to an output terminal of the first trigger, and a second input terminal of the first AND operator is used to obtain the clock signal;

[0021] a second trigger, wherein a set terminal of the second trigger is connected to an output terminal of the first AND operator, a reset terminal of the second trigger is connected to an output terminal of the pulse width modulation module, and an output terminal of the second trigger is connected to a second input terminal of the first OR operator;

[0022] A second driving submodule, wherein the input end of the second driving submodule is connected to the output end of the second trigger, and the output end of the second driving submodule is connected to the switch tube driving end of the switching power supply.

[0023] In one embodiment, the first regulation submodule comprises:

[0024] A third inverter, wherein an input terminal of the third inverter is connected to an output terminal of the pulse width modulation module;

[0025] a third trigger, wherein an input terminal of the third trigger is connected to an output terminal of the third inverter, and a clock terminal of the third trigger is used to obtain a clock signal;

[0026] A second AND operator, wherein a first input terminal of the second AND operator is connected to an output terminal of the third trigger;

[0027] A third driver submodule, wherein the input end of the third driver submodule is connected to the output end of the second AND operator, and the output end of the third driver submodule is connected to the freewheeling tube driving end of the switching power supply.

[0028] In one embodiment, the second regulation submodule comprises:

[0029] A third AND operator, wherein a first input terminal of the third AND operator is connected to an output terminal of the third trigger, and a second input terminal of the third AND operator is used to obtain the clock signal;

[0030] a fourth trigger, wherein a set terminal of the fourth trigger is connected to an output terminal of the third AND operator, and a reset terminal of the fourth trigger is connected to an output terminal of the pulse width modulation module;

[0031] a fourth inverter, wherein an input terminal of the fourth inverter is connected to an output terminal of the fourth trigger, and an output terminal of the fourth inverter is connected to a second input terminal of the second AND operator;

[0032] A fourth driving submodule, wherein the input end of the fourth driving submodule is connected to the output end of the fourth inverter, and the output end of the fourth driving submodule is connected to the switch tube driving end of the switching power supply.

[0033] In one embodiment, the pulse width modulation module includes:

[0034] A voltage division feedback module, connected to the output end of the switching power supply, for performing voltage division processing on the output voltage signal to obtain a voltage feedback signal;

[0035] An operational amplifier module, connected to the voltage-dividing feedback module, and configured to obtain a compensation voltage signal according to the voltage feedback signal and a reference voltage signal;

[0036] The comparison module is connected to the current sampling terminal of the switching power supply and the operational amplifier module, and is used to output a pulse width modulation signal according to the current sampling signal and the compensation voltage signal.

[0037] In one embodiment, the voltage division feedback module includes:

[0038] A first resistor, one end of which is connected to the output end of the switching power supply;

[0039] a second resistor, one end of the second resistor being connected to the other end of the first resistor, and the other end of the second resistor being grounded;

[0040] The operational amplifier module comprises:

[0041] An operational amplifier, wherein an inverting input terminal of the operational amplifier is connected to a common terminal of the first resistor and the second resistor, and a non-inverting input terminal of the operational amplifier is used to obtain a reference voltage.

[0042] In one embodiment, the comparison module comprises:

[0043] A comparator, wherein the non-inverting input terminal of the comparator is connected to the current sampling terminal of the switching power supply to obtain the current sampling signal, the inverting input terminal of the comparator is connected to the output terminal of the operational amplifier, and the output terminal of the comparator serves as the output terminal of the pulse width modulation module to output the pulse width modulation signal.

[0044] The present application provides an electronic device, comprising a switching power supply protection circuit based on a forced continuous mode as described in any one of the above embodiments.

[0045] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0046] The pulse width modulation module outputs a pulse width modulation signal PWM according to the output voltage signal and the current sampling signal. When the input inductance energy of the switching power supply is greater than the output inductance energy, the control module controls the freewheeling tube of the switching power supply to be turned off according to the pulse width modulation signal PWM and the clock signal. The pulse width modulation signal PWM and the clock signal clk jointly determine the switching duty cycle of the switching power supply, so that when the input inductance energy of the switching power supply is greater than the output inductance energy, the freewheeling tube of the switching power supply is controlled to be turned off.

[0047] When the input inductance energy of the switching power supply is greater than the output inductance energy, the output voltage signal VOUT of the switching power supply increases, and the freewheeling tube of the switching power supply is regulated to be turned off, which can also be understood as the first freewheeling tube of the boost converter being turned off, or the second freewheeling tube of the buck converter being turned off. When the freewheeling tube of the switching power supply is turned off, the first freewheeling tube is turned off or the second freewheeling tube is turned off, which avoids the first freewheeling tube or the second freewheeling tube being turned on for a long time and causing excessive negative current.

[0048] Furthermore, the switching power supply protection circuit based on the forced continuous mode provided by the present application avoids the excessive negative current caused by the freewheeling tube in the switching power supply being turned on for a long time, and solves the problem of excessive negative current in the inductor current in the traditional switching power supply. Thus, the switching power supply protection circuit based on the forced continuous mode provided by the present application can protect the switching power supply in the forced continuous mode, solving the problem of excessive reverse current in the inductor in the traditional switching power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic diagram of the structure of a switching power supply protection circuit based on a forced continuous mode in some embodiments provided in the present application.

[0050] Figure 2 This is a schematic diagram of the circuit structure when the switching power supply is a boost converter in some embodiments provided in the present application.

[0051] Figure 3 This is a schematic diagram of the circuit structure when the switching power supply is a buck converter in some embodiments provided in the present application.

[0052] Figure 4 A schematic diagram of the circuit structure of a first regulating submodule and a second regulating submodule corresponding to a boost converter in some embodiments provided in the present application in which the switching power supply is a boost converter.

[0053] Figure 5 In some embodiments provided in this application Figure 4 The signal change schematic diagram corresponding to the circuit structure schematic diagram shown.

[0054] Figure 6A schematic diagram of the circuit structure of a first regulating submodule and a second regulating submodule corresponding to a step-down converter in which the switching power supply is provided in some embodiments of the present application.

[0055] Figure 7 A schematic diagram of the circuit structure of a pulse width modulation module corresponding to a boost converter in which the switching power supply is provided in some embodiments of the present application.

[0056] Figure 8 A schematic diagram of the circuit structure of a pulse width modulation module corresponding to a step-down converter in which the switching power supply is provided in some embodiments of the present application.

[0057] Fig. 9 Schematic diagram of the circuit structure of a boost converter, a voltage divider feedback module, an operational amplifier module, and a comparison module in some embodiments provided in the present application.

[0058] Fig.10 Schematic diagram of the circuit structure of a buck converter, a voltage divider feedback module, an operational amplifier module, and a comparison module in some embodiments provided in the present application.

[0059] Fig.11 A schematic diagram of signal changes in the circuit structure corresponding to the boost converter in an abnormal situation of the forced continuous mode in some embodiments provided in the present application. DETAILED DESCRIPTION

[0060] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0061] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0062] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0063] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0064] See also Figure 1 The present application provides a switching power supply protection circuit 100 based on a forced continuous mode. The switching power supply protection circuit 100 based on the forced continuous mode is applied to the switching power supply 10, and the switching power supply 10 is used to convert the input voltage in the forced continuous mode to obtain an output voltage signal. The switching power supply 10 can realize the mutual conversion between the DC input voltage and the DC output voltage. The switching power supply 10 includes components such as a switching tube, a freewheeling tube, an inductor and a capacitor. The voltage conversion is realized by controlling the conduction and shutdown of the switching tube and the conduction and shutdown of the freewheeling tube in the switching power supply 10 through the switching power supply protection circuit 100 based on the forced continuous mode. The inductor in the switching power supply 10 can store energy and transfer energy.

[0065] See also Figure 2 In one embodiment, the switching power supply 10 includes a first freewheeling tube 111, a first switch tube 112, a first inductor 113 and a first capacitor 114. The first freewheeling tube 111 is a P-channel field-effect transistor (PFET). The first switch tube 112 is an N-channel field-effect transistor (NFET). One end of the first inductor 113 is connected to the voltage input terminal VIN. The other end of the first inductor 113 is connected to the source of the first freewheeling tube 111. The drain of the first freewheeling tube 111 is connected to the load as the output end of the switching power supply 10. The drain of the first freewheeling tube 111 is connected to one end of the first capacitor 114. The other end of the first capacitor 114 is grounded. The gate of the first freewheeling tube 111, as the freewheeling tube driving end of the switching power supply 10, is connected to the control end of the control module 30. The other end of the first inductor 113 is connected to the drain of the first switch tube 112. The other end of the first inductor 113, the drain of the first switch tube 112, and the source of the first freewheeling tube 111 form a common end, which serves as a current sampling end of the switching power supply 10. The source of the first switch tube 112 is grounded. The gate of the first switch tube 112, as the switch tube driving end of the switching power supply 10, is connected to the control end of the control module 30. The first freewheeling tube 111, the first switch tube 112, the first inductor 113, and the first capacitor 114 form a boost converter.

[0066] See also Figure 3 In one embodiment, the switching power supply 10 includes a second freewheeling tube 121, a second switch tube 122, a second inductor 123 and a second capacitor 124. The second freewheeling tube 121 is an N-type channel field effect transistor NFET. The second switch tube 122 is a P-type channel field effect transistor PFET. The source of the second switch tube 122 is connected to the voltage input terminal VIN. The gate of the second switch tube 122, as the switch tube driving end of the switching power supply 10, is connected to the control end of the control module 30. The drain of the second switch tube 122 is connected to one end of the second inductor 123. The other end of the second inductor 123 is connected to the load as the output end of the switching power supply 10. One end of the second capacitor 124 is connected to the other end of the second inductor 123. The other end of the second capacitor 124 is grounded. The gate of the second freewheeling tube 121, as the freewheeling tube driving end of the switching power supply 10, is connected to the control end of the control module 30. The drain of the second freewheeling tube 121 is connected to the drain of the second switch tube 122, and is connected to one end of the second inductor 123. The drain of the second freewheeling tube 121, the drain of the second switch tube 122, and one end of the second inductor 123 form a common end, which serves as a current sampling end of the switching power supply 10. The source of the second freewheeling tube 121 is grounded. The second freewheeling tube 121, the second switch tube 122, the second inductor 123, and the second capacitor 124 form a buck converter.

[0067] The switching power supply protection circuit 100 based on the forced continuous mode includes a pulse width modulation module 20 and a control module 30. The first input terminal of the pulse width modulation module 20 is connected to the output terminal of the switching power supply 10, and is used to obtain a voltage feedback signal of the output voltage signal VOUT. The output voltage signal VOUT can reflect the output voltage of the switching power supply 10, and is fed back to the first input terminal of the pulse width modulation module 20 as a feedback signal of the output terminal of the switching power supply 10.

[0068] The second input terminal of the pulse width modulation module 20 is connected to the current sampling terminal of the switching power supply 10, and the current sampling signal in the switching power supply 10 can be obtained in real time, which can reflect the change of the current in the switching power supply 10 and is embodied in the form of a voltage signal V4. The pulse width modulation module 20 is used to output a pulse width modulation signal (Pulse Width Modulation, PWM) according to the output voltage signal and the current sampling signal. PWM is a digital signal that controls energy transmission by controlling the length of time that a high level (or low level) appears (which can also be understood as pulse width, duty cycle). Through the pulse width modulation module 20, the pulse width modulation signal PWM can be dynamically adjusted according to the changes in the voltage and current in the switching power supply 10 to achieve a fast dynamic response and deal with abnormal conditions in the switching power supply 10.

[0069] In the case of an abnormal situation in the forced continuous mode, for example, when the output load of the switching power supply 10 changes from a heavy load to a light load, the power supply continuously inputs energy to the inductor during the on-stage of the switch tube. In the inductor discharge stage (the off-stage of the switch tube), the inductor cannot effectively release the stored energy to the load due to the load change, resulting in excess inductor energy in the switching power supply 10. Excess inductor energy in the switching power supply 10 can also be understood as the input inductor energy of the switching power supply 10 being greater than the output inductor energy. When the input inductor energy of the switching power supply 10 is greater than the output inductor energy, the output voltage signal VOUT of the switching power supply 10 increases, causing an excessive current to flow in the reverse direction through the first freewheeling tube 111 to the first inductor 113. Alternatively, when the input inductor energy of the switching power supply 10 is greater than the output inductor energy, the output voltage signal VOUT of the switching power supply 10 increases, causing an excessive current to flow in the reverse direction through the second inductor 123 to the second freewheeling tube 121. It can be seen from this that when the input inductor energy of the switching power supply 10 is greater than the output inductor energy, the inductor current will have an excessively large negative current.

[0070] The signal end of the control module 30 is connected to the output end of the pulse width modulation module 20. The control end of the control module 30 is connected to the driving end of the switching power supply 10. The control module 30 is used to control the freewheeling tube of the switching power supply 10 to be turned off according to the pulse width modulation signal PWM and the clock signal when the input inductance energy of the switching power supply 10 is greater than the output inductance energy. The pulse width modulation signal PWM and the clock signal clk jointly determine the switching duty cycle of the switching power supply 10, so that when the input inductance energy of the switching power supply 10 is greater than the output inductance energy, the freewheeling tube of the switching power supply 10 is controlled to be turned off. The freewheeling tube of the switching power supply 10 can be a first freewheeling tube 111 or a second freewheeling tube 121.

[0071] When the input inductance energy of the switching power supply 10 is greater than the output inductance energy, the output voltage signal VOUT of the switching power supply 10 increases, and the freewheeling tube of the switching power supply 10 is regulated to be turned off, which can also be understood as the first freewheeling tube 111 of the boost converter being turned off, or the second freewheeling tube 121 of the buck converter being turned off. When the freewheeling tube of the switching power supply 10 is turned off, the first freewheeling tube 111 is turned off or the second freewheeling tube 121 is turned off, which avoids the first freewheeling tube or the second freewheeling tube being turned on for a long time and causing excessive negative current.

[0072] Furthermore, the switching power supply protection circuit 100 based on the forced continuous mode provided by the present application avoids excessive negative current caused by the freewheeling tube in the switching power supply 10 being turned on for a long time, and solves the problem of excessive negative current in the inductor current in the traditional switching power supply system. Therefore, the switching power supply protection circuit 100 based on the forced continuous mode provided by the present application can protect the switching power supply 10 in the forced continuous mode, solving the problem of excessive reverse current of the inductor in the traditional technology.

[0073] In one embodiment, the control module 30 includes a first control submodule 310 and a second control submodule 320. The first signal input end of the first control submodule 310 is connected to the output end of the pulse width modulation module 20 for obtaining a pulse width modulation signal PWM. The second signal input end of the first control submodule 310 is used to obtain a clock signal. The control end of the first control submodule 310 is connected to the freewheeling tube driving end of the switching power supply 10. In one embodiment, the freewheeling tube driving end of the switching power supply 10 is used to drive the first freewheeling tube 111 in the boost converter to turn on or off. In one embodiment, the freewheeling tube driving end of the switching power supply 10 is used to drive the second freewheeling tube 121 in the buck converter to turn on or off.

[0074] In one embodiment, the first regulating submodule 310 includes a trigger, a logic operator, a driving circuit, etc., which can be adjusted and designed according to actual needs.

[0075] The first signal input end of the second regulating submodule 320 is connected to the output end of the pulse width modulation module 20, and is used to obtain the pulse width modulation signal PWM. The second signal input end of the second regulating submodule 320 is used to obtain the clock signal. The second signal input end of the second regulating submodule 320 is also connected to the signal regulating end of the first regulating submodule 310. The signal regulating end of the second regulating submodule 320 is connected to the third signal input end of the first regulating submodule 310. The control end of the second regulating submodule 320 is connected to the switch tube driving end of the switching power supply 10. In one embodiment, the switch tube driving end of the switching power supply 10 is used to drive the first switch tube 112 in the boost converter to turn on or off. In one embodiment, the switch tube driving end of the switching power supply 10 is used to drive the second switch tube 122 in the buck converter to turn on or off.

[0076] In one embodiment, the second regulating submodule 320 includes a trigger, a logic operator, a driving circuit, etc., which can be adjusted and designed according to actual needs.

[0077] The first regulating submodule 310 is used to regulate the conduction or shutdown of the freewheeling tube of the switching power supply 10 according to the pulse width modulation signal, the clock signal and the regulation signal output by the signal regulation end of the second regulating submodule 320. The second regulating submodule 320 is used to regulate the conduction or shutdown of the switch tube of the switching power supply 10 according to the pulse width modulation signal, the clock signal and the regulation signal output by the signal regulation end of the first regulating submodule 310. The first regulating submodule 310 and the second regulating submodule 320 influence each other through the regulation signal output by the signal regulation end, and can complement each other's information, realize collaborative work, and realize signal interaction and synergy. Through the mutual coordination of the first regulating submodule 310 and the second regulating submodule 320, the freewheeling tube in the switching power supply 10 is controlled to be turned on or off and the switch tube is turned on or off, which can ensure that the switch tube and the freewheeling tube are alternately turned on in the normal working state of the forced continuous mode of the switching power supply 10, so as to realize the boost or buck of the switching power supply 10. At the same time, the first regulating submodule 310 and the second regulating submodule 320 cooperate with each other to control the on or off of the freewheeling tube and the on or off of the switch tube in the switching power supply 10, so as to ensure that when the switching power supply 10 is in an abnormal situation of the forced continuous mode, for example, when the input inductance energy of the switching power supply 10 is greater than the output inductance energy, the freewheeling tube of the switching power supply 10 is regulated to be turned off, thereby avoiding the first freewheeling tube or the second freewheeling tube being turned on for a long time and causing excessive negative current, and solving the problem of excessive negative current in the inductor current in the traditional switching power supply system.

[0078] See also Figure 4 In one embodiment, the first control submodule 310 includes a first inverter 3111, a first trigger 3112, a second inverter 3113, a first OR operator 3114, and a first driving submodule 3115. The input end of the first inverter 3111 is connected to the output end of the pulse width modulation module 20, and the pulse width modulation signal PWM can be obtained. The first inverter 3111 can quickly invert the pulse width modulation signal PWM, invert the logic level of PWM, and output the inverted signal to the first trigger 3112.

[0079] The input end (i.e., the D end) of the first trigger 3112 is connected to the output end of the first inverter 3111. The clock end (i.e., the clk end) of the first trigger 3112 is used to obtain the clock signal. The first trigger 3112 can be a D trigger. When the rising edge of the clock signal clk arrives, the input end of the D trigger is high, and the Q output end of the D trigger also becomes high. If the input end of the D trigger is low, the Q output end of the D trigger also becomes low. The D trigger has the function of storing data. Under the control of the clock signal clk, it can store the signal at the input end and output the signal stably at the output end until the next valid clock edge arrives. The output state update of the D trigger is strictly controlled by the clock signal, has the advantages of strong anti-interference ability, and is easy to implement sequential logic control.

[0080] The input end of the second inverter 3113 is connected to the output end (i.e., the Q end) of the first trigger 3112. The first input end of the first OR operator 3114 is connected to the output end of the second inverter 3113. The first OR operator 3114 can also be understood as an OR logic gate. The input end of the first driver module 3115 is connected to the output end of the first OR operator 3114, and the output end of the first driver module 3115 is connected to the freewheeling tube driving end of the switching power supply 10. The first driver module 3115 multiplies the voltage of the output level signal of the first OR operator 3114, and outputs the freewheeling tube driving voltage V7 to provide a driving voltage to drive the freewheeling tube to turn on or off. In one embodiment, the first driver module 3115 may include a driver circuit or a charge pump circuit, etc., to multiply the input signal to meet the voltage requirement of driving the freewheeling tube.

[0081] In one embodiment, the second regulation submodule 320 includes a first AND operator 3211, a second trigger 3212, and a second driving submodule 3213. The first input end of the first AND operator 3211 is connected to the output end of the first trigger 3112. The second input end of the first AND operator 3211 is used to obtain a clock signal. The first AND operator 3211 can be understood as an AND logic gate.

[0082] The set end (i.e., the S end) of the second trigger 3212 is connected to the output end of the first AND operator 3211. The reset end (i.e., the R end) of the second trigger 3212 is connected to the output end of the pulse width modulation module 20, and the pulse width modulation signal PWM can be obtained. The output end (i.e., the Q end) of the second trigger 3212 is connected to the second input end of the first OR operator 3114.

[0083] The second trigger 3212 is an RS trigger composed of a NOR gate. If the set end (i.e., S end) of the second trigger 3212 is at a high level and the reset end (i.e., R end) is at a low level, the output end (i.e., Q end) of the second trigger 3212 is at a high level. If the reset end (i.e., R end) of the second trigger 3212 is at a high level and the set end (i.e., S end) is at a low level, the output end (i.e., Q end) of the second trigger 3212 is at a low level. The RS trigger has a memory function, can store binary information, and has a strong anti-interference ability.

[0084] The input end of the second driver module 3213 is connected to the output end of the second trigger 3212. The output end of the second driver module 3213 is connected to the switch tube driving end of the switching power supply 10. The second driver module 3213 voltage-multiplies the level signal output by the output end (i.e., the Q end) of the second trigger 3212, and outputs the switch tube driving voltage V6 to provide a driving voltage to drive the switch tube to turn on or off. In one embodiment, the second driver submodule 3213 may include a driver circuit or a charge pump circuit, etc., to double the voltage of the input signal to meet the voltage requirement of driving the switch tube.

[0085] See also Figure 5 , under normal working conditions of the forced continuous mode, the compensation voltage signal V3 is located above the minimum value of the voltage signal V4, which can also be understood as the compensation voltage signal V3 being greater than the minimum value of the voltage signal V4. When the clock signal clk is at a high level and PWM is at a low level, the PWM low level passes through the first inverter 3111 and outputs a high level to the input end of the first trigger 3112. The first trigger 3112 is a D trigger. When the rising edge of the clock signal clk arrives, the input end of the first trigger 3112, that is, the D end, is at a high level. When the input end and the clock end of the first trigger 3112 are both at a high level, the output end of the first trigger 3112, that is, the Q end, is at a high level, that is, V5 is at a high level. The high level output by the output end of the first trigger 3112 outputs a low level after passing through the second inverter 3113 and is transmitted to the first input end of the first OR operator 3114.

[0086] The high level outputted from the output terminal of the first trigger 3112 is transmitted to the first input terminal of the first AND operator 3211. The second input terminal of the first AND operator 3211 is the clock signal clk, which is at a high level. The second trigger 3212 is an RS trigger composed of a NOR gate. Furthermore, after the AND operation of the first AND operator 3211, a high level is outputted to the set terminal, i.e., the S terminal, of the second trigger 3212. The reset terminal, i.e., the R terminal, of the second trigger 3212 is inputted with a PWM signal, i.e., a low level. If the S terminal of the second trigger 3212 is at a high level and the R terminal is at a low level, then the output terminal, i.e., the Q terminal, of the second trigger 3212 is at a high level. The high level outputted from the output terminal of the second trigger 3212 is to the second input terminal of the first OR operator 3114.

[0087] The first input terminal of the first OR operator 3114 is at a low level, and the second input terminal is at a high level. After the OR operation, the output is at a high level. The output terminal of the first OR operator 3114 outputs a high level to the input terminal of the first driver submodule 3115. The first driver submodule 3115 multiplies the voltage of the high level output by the first OR operator 3114, and outputs a freewheeling tube driving voltage V7 to provide a driving voltage to drive the freewheeling tube to turn off.

[0088] The output terminal of the second trigger 3212 outputs a high level to the input terminal of the second driver module 3213. The second driver module 3213 multiplies the voltage of the high level output of the second trigger 3212 and outputs a switch tube driving voltage V6 to provide a driving voltage to drive the switch tube to conduct.

[0089] Then, the current of the switch tube gradually increases, and the voltage of the voltage signal V4 gradually increases accordingly. When the voltage of the voltage signal V4 is greater than the compensation voltage signal V3, the PWM signal outputs a high level to the input end of the first inverter 3111 and the reset end of the second trigger 3212, i.e., the R end. When the clock signal clk is at a low level, the output end of the first trigger 3112, i.e., the Q end, maintains a high level, i.e., V5 is at a high level. The high level output from the output end of the first trigger 3112 and the low level of the clock signal clk, after the AND operation of the first AND operator 3211, output a low level to the set end of the second trigger 3212, i.e., the S end.

[0090] The PWM signal is at a high level and is transmitted to the reset end, i.e., the R end, of the second trigger 3212. The reset end of the second trigger 3212 is at a high level and the set end is at a low level, so that the output end of the second trigger 3212 is at a low level and is transmitted to the input end of the second driver module 3213. After passing through the second driver module 3213, the switch tube is turned off. At the same time, the output end, i.e., the Q end, of the first trigger 3112 maintains a high level, and is changed to a low level through the second inverter 3113, and is input to the first input end of the first OR operator 3114. The low level output from the output end of the second trigger 3212 is input to the second input end of the first OR operator 3114, so that the output end of the first OR operator 3114 is at a low level. The low level output from the output end of the first OR operator 3114 is still at a low level after passing through the first driver module 3115, and controls the freewheeling tube to be turned on.

[0091] Thus, through the first regulating submodule 310 and the second regulating submodule 320 , it is achieved that the switch tube and the freewheeling tube in the switching power supply 10 are alternately turned on under normal working conditions of the forced continuous mode.

[0092] See also Figure 6 In one embodiment, the first control submodule 310 includes a third inverter 3121, a third trigger 3122, a second AND operator 3123, and a third driving submodule 3124. The input end of the third inverter 3121 is connected to the output end of the pulse width modulation module 20. The pulse width modulation signal PWM is obtained through the input end of the third inverter 3121. The third inverter 3121 can quickly invert the pulse width modulation signal PWM, invert the logic level of PWM, and output the inverted signal to the third trigger 3122. The first inverter 3111, the second inverter 3113, the third inverter 3121, and the fourth inverter 3223 are the same, and are all inverters.

[0093] The input terminal (i.e., the D terminal) of the third flip-flop 3122 is connected to the output terminal of the third inverter 3121, and the clock terminal (i.e., the clk terminal) of the third flip-flop 3122 is used to obtain the clock signal. The first input terminal of the second AND operator 3123 is connected to the output terminal (i.e., the Q terminal) of the third flip-flop 3122. The second AND operator 3123 can be understood as an AND logic gate. The third flip-flop 3122 can be a D flip-flop.

[0094] The input end of the third driver module 3124 is connected to the output end of the second AND operator 3123. The output end of the third driver module 3124 is connected to the freewheeling tube driving end of the switching power supply 10. The third driver module 3124 voltage-multiplies the output level signal of the second AND operator 3123, and outputs the freewheeling tube driving voltage V7 to provide a driving voltage to drive the freewheeling tube to turn on or off. In one embodiment, the third driver module 3124 may include a driver circuit or a charge pump circuit, etc., to double the input signal to meet the voltage requirement of driving the freewheeling tube.

[0095] In one embodiment, the second regulation submodule 320 includes a third AND operator 3221, a fourth trigger 3222, a fourth inverter 3223, and a fourth driving submodule 3224. The first input end of the third AND operator 3221 is connected to the output end (i.e., the Q end) of the third trigger 3122, and the level signal V5 of the output end of the third trigger 3122 can be obtained. The second input end of the third AND operator 3221 is used to obtain a clock signal. The third AND operator 3221 can be understood as an AND logic gate.

[0096] The set end (i.e., the S end) of the fourth flip-flop 3222 is connected to the output end of the third AND operator 3221. The reset end (i.e., the R end) of the fourth flip-flop 3222 is connected to the output end of the pulse width modulation module 20, and the pulse width modulation signal PWM can be obtained. The input end of the fourth inverter 3223 is connected to the output end (i.e., the Q end) of the fourth flip-flop 3222. The output end of the fourth inverter 3223 is connected to the second input end of the second AND operator 3123.

[0097] The fourth flip-flop 3222 is an RS flip-flop composed of a NOR gate. If the set terminal (i.e., the S terminal) of the fourth flip-flop 3222 is at a high level and the reset terminal (i.e., the R terminal) is at a low level, then the output terminal (i.e., the Q terminal) of the fourth flip-flop 3222 is at a high level. If the reset terminal (i.e., the R terminal) of the fourth flip-flop 3222 is at a high level and the set terminal (i.e., the S terminal) is at a low level, then the output terminal (i.e., the Q terminal) of the fourth flip-flop 3222 is at a low level.

[0098] The input end of the fourth driver module 3224 is connected to the output end of the fourth inverter 3223. The output end of the fourth driver module 3224 is connected to the switch tube driving end of the switching power supply 10. The fourth driver module 3224 voltage-multiplies the level signal output from the output end of the fourth inverter 3223, and outputs the switch tube driving voltage V6 to provide a driving voltage to drive the switch tube to turn on or off. In one embodiment, the fourth driver submodule 3224 may include a driver circuit or a charge pump circuit, etc., to double the input signal to meet the voltage requirement of driving the switch tube.

[0099] See also Figure 7 and Figure 8 In one embodiment, the pulse width modulation module 20 includes a voltage division feedback module 210, an operational amplifier module 220, and a comparison module 230. The voltage division feedback module 210 is connected to the output end of the switching power supply 10, and is used to perform voltage division processing on the output voltage signal VOUT to obtain a voltage feedback signal V1.

[0100] The operational amplifier module 220 is connected to the voltage-dividing feedback module 210, and is used to obtain the compensation voltage signal V3 according to the voltage feedback signal V1 and the reference voltage signal V2. The comparison module 230 is connected to the current sampling terminal of the switching power supply 10 and the operational amplifier module 220, and is used to output the pulse width modulation signal PWM according to the current sampling signal and the compensation voltage signal V3. Among them, the current sampling signal is embodied in the form of a voltage signal V4.

[0101] The output voltage signal VOUT is divided by the voltage-dividing feedback module 210 to form a voltage feedback signal V1, which can reflect the change of the output voltage signal VOUT. In one embodiment, the voltage-dividing feedback module 210 includes a plurality of components such as resistors and potentiometers, which can be set according to the actual application scenario. The circuit structure of the voltage-dividing feedback module 210 is simple, low-cost, and has good signal adaptability. It can accurately feedback the voltage change of the output voltage signal VOUT, and realize accurate adjustment of the subsequent pulse width modulation signal PWM.

[0102] The inverting input terminal of the operational amplifier module 220 is connected to the voltage divider feedback module 210 to obtain the voltage feedback signal V1. The reference voltage signal V2 is used as the signal of the non-inverting input terminal of the operational amplifier module 220. The operational amplifier module 220 generates a compensation voltage signal V3 by comparing the voltage feedback signal V1 with the reference voltage signal V2, and realizes the operation of the error amplification signal of the two. The value of the reference voltage signal V2 can be set according to the actual application scenario. The voltage feedback signal V1 is compared with the expected reference voltage signal V2 by the operational amplifier module 220 to obtain an error signal. The error signal is amplified by the operational amplifier module 220 to obtain the compensation voltage signal V3. Furthermore, according to the current sampling signal and the compensation voltage signal V3, the pulse width modulation signal PWM is accurately adjusted. In one embodiment, the operational amplifier module 220 includes components such as an operational amplifier and a resistor, which can be set according to the actual application scenario.

[0103] The current sampling signal, in the form of a voltage signal V4, is input to the non-inverting input terminal of the comparison module 230. The compensation voltage signal V3 is input to the inverting input terminal of the comparison module 230. The comparison module 230 generates a pulse width modulation signal PWM by comparing the current sampling signal with the compensation voltage signal V3. The pulse width modulation signal PWM and the clock signal clk jointly determine the switching duty cycle of the power tube in the switching power supply 10. In one embodiment, the comparison module 230 includes components such as a comparator and a resistor, which can be set according to the actual application scenario.

[0104] The pulse width modulation module 20 is formed by the voltage-dividing feedback module 210, the operational amplifier module 220 and the comparison module 230, and can accurately collect the voltage feedback signal V1 and the current sampling signal (in the form of the voltage signal V4), and accurately reflect the voltage and current changes in the switching power supply 10 to the pulse width modulation module 20. The pulse width modulation module 20 compares the voltage feedback signal V1 with the reference voltage signal V2, and compares the compensation voltage signal V3 with the voltage signal V4, and can accurately compare the input signal, thereby generating a high-precision pulse width modulation signal PWM, and can sensitively judge the slight difference of the input signal, and control the conduction and shutdown of the freewheeling tube and the switch tube in the switching power supply 10 to achieve efficient energy conversion.

[0105] See also Fig. 9 and Fig.10 In one embodiment, the voltage-dividing feedback module 210 includes a first resistor 211 and a second resistor 212. One end of the first resistor 211 is connected to the output end of the switching power supply 10. One end of the second resistor 212 is connected to the other end of the first resistor 211, and the other end of the second resistor 212 is grounded. The common end of the first resistor 211 and the second resistor 212 serves as the output end of the voltage-dividing feedback module 210. The first resistor 211 and the second resistor 212 form a voltage-dividing network, which divides the output voltage signal VOUT to generate a voltage feedback signal V1. In one embodiment, the resistance values ​​of the first resistor 211 and the second resistor 212 can be adjusted according to the actual application scenario. The first resistor 211 and the second resistor 212 form a voltage-dividing feedback module 210, which has the advantages of simple circuit, low cost and flexible voltage regulation.

[0106] The operational amplifier module 220 includes an operational amplifier 221. The inverting input terminal of the operational amplifier 221 is connected to the common terminal of the first resistor 211 and the second resistor 212, that is, the input voltage feedback signal V1. The non-inverting input terminal of the operational amplifier 221 is used to obtain the reference voltage signal V2. In one embodiment, the parameter setting of the operational amplifier 221 can be adjusted according to the actual application scenario. Through the operational amplifier 221, it is possible to amplify the small error signal of the voltage feedback signal V1 and the reference voltage signal V2, thereby improving the accuracy of the error calculation.

[0107] In one embodiment, the comparison module 230 includes a comparator 231. The non-inverting input terminal of the comparator 231 is connected to the current sampling terminal of the switching power supply 10 to obtain a current sampling signal. The current sampling signal is embodied in the form of a voltage signal V4. The inverting input terminal of the comparator 231 is connected to the output terminal of the operational amplifier 221 to obtain the compensation voltage signal V3. The output terminal of the comparator 231 is used as the output terminal of the pulse width modulation module 20 to output a pulse width modulation signal PWM.

[0108] The comparator 231 has the advantages of high gain, low offset voltage, anti-interference ability and fast response, and can make sensitive and fast judgments on small differences in input signals. Through the comparator 231, the compensation voltage signal V3 and the voltage signal V4 can be accurately compared, thereby generating a high-precision pulse width modulation signal PWM, and the level state of the pulse width modulation signal PWM can be quickly and accurately switched, thereby improving the dynamic response performance of the switching power supply protection circuit 100 based on the forced continuous mode.

[0109] See also Fig.11 In one embodiment, Figure 2 Taking the circuit structure shown as an example, in the abnormal situation of the forced continuous mode, for example, when the output load of the switching power supply 10 changes from heavy load to light load, the inductor energy in the switching power supply 10 is excessive, which can also be understood as when the input inductor energy is greater than the output inductor energy, the output voltage VOUT of the switching power supply 10 increases. The output voltage VOUT of the switching power supply 10 increases, so that the voltage feedback signal V1 becomes larger, and then after passing through the operational amplifier 221, it is compared with the reference voltage signal V2, so that the output compensation voltage signal V3 decreases. When the compensation voltage signal V3 is less than the minimum value of the voltage signal V4 corresponding to the current sampling signal, the PWM signal output after passing through the comparator 231 is high level and is always maintained at a high level.

[0110] Thus, when the clock signal clk becomes high level, the PWM signal is still high level. After passing through the first inverter 3111, it is converted to low level and transmitted to the input end of the first trigger 3112, that is, the D end. The clock end of the first trigger 3112, that is, the clk end, is high level, so that the output end of the first trigger 3112, that is, the Q end, is low level, and is transmitted to the input end of the second inverter 3113 and the first input end of the first AND operator 3211. The second input end of the first AND operator 3211 is the clock signal. After the first AND operator 3211 performs AND operation, the output end of the first AND operator 3211 outputs a low level to the set end of the second trigger 3212, that is, the S end. The reset end of the second trigger 3212, that is, the R end, is the PWM signal, which is high level. The output end of the second trigger 3212 maintains a low level. The low level output by the output end of the second trigger 3212 passes through the second driver submodule 3213, so that the switch tube is turned off and no longer conducts.

[0111] At the same time, the output end of the first trigger 3112, that is, the Q end, is at a low level, that is, V5 is at a low level. After being converted by the second inverter 3113, it is at a high level and is transmitted to the first input end of the first OR operator 3114. The second input end of the first OR operator 3114 is connected to the output end of the second trigger 3212 and is at a low level. Furthermore, after the first OR operator 3114 performs an OR operation, the output end of the first OR operator 3114 outputs a high level and is transmitted to the first driver submodule 3115. The first driver submodule 3115 performs voltage multiplication on the high level output by the first OR operator 3114, maintains the output freewheeling tube driving voltage V7, and provides a driving voltage to drive the freewheeling tube to maintain a closed state. Thus, the switch tube in the switching power supply 10 is turned off, and the freewheeling tube in the switching power supply 10 is also turned off, so that the current of the inductor in the switching power supply 10 is maintained at 0A, avoiding the existence of excessive inductor negative current in the switching power supply 10. Therefore, through the switching power supply protection circuit 100 based on the forced continuous mode provided in the present application, the switching power supply 10 can be protected in the forced continuous mode, avoiding the existence of excessive inductor negative current in the switching power supply 10, and solving the problem of excessive inductor reverse current in traditional technology.

[0112] further, Fig.11 The dotted line of the inductor current IL in the figure shows the trend of the inductor current under abnormal conditions using traditional technology. Fig.11 It can also be seen from the inductor current IL of the switching power supply 10 that, through the switching power supply protection circuit 100 based on the forced continuous mode provided by the present application, when the input inductor energy is greater than the output inductor energy, the inductor current IL can be maintained at 0A, thereby avoiding the existence of excessive negative inductor current in the switching power supply 10.

[0113] The present application provides an electronic device, including the switching power supply protection circuit 100 based on the forced continuous mode in any of the above embodiments. The electronic device can be a mobile phone, a laptop computer, a digital camera, an industrial robot or a car management system.

[0114] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated in one processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit, and the above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application.

[0115] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0116] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0117] The division of modules or units is only a logical function division, and there may be other divisions in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices or units, which may be electrical, mechanical or other forms.

[0118] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, each functional unit in each embodiment of the present application may be integrated into a processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware or in the form of software functional units.

[0119] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A switching power supply protection circuit based on forced continuous mode, characterized in that: Applied to a switching power supply (10), the switching power supply (10) is used to convert an input voltage in a forced continuous mode to obtain an output voltage signal, the circuit comprising: a pulse width modulation module (20), wherein a first input end of the pulse width modulation module (20) is connected to an output end of the switching power supply (10), a second input end of the pulse width modulation module (20) is connected to a current sampling end of the switching power supply (10), and the pulse width modulation module (20) is used to output a pulse width modulation signal according to the output voltage signal and the current sampling signal; a first regulating submodule (310), wherein a first signal input end of the first regulating submodule (310) is connected to an output end of the pulse width modulation module (20), a second signal input end of the first regulating submodule (310) is used to obtain a clock signal, and a control end of the first regulating submodule (310) is connected to a freewheeling tube driving end of the switching power supply (10); a second regulating submodule (320), wherein a first signal input terminal of the second regulating submodule (320) is connected to an output terminal of the pulse width modulation module (20), a second signal input terminal of the second regulating submodule (320) is used to obtain the clock signal, the second signal input terminal of the second regulating submodule (320) is also connected to a signal regulating terminal of the first regulating submodule (310), the signal regulating terminal of the second regulating submodule (320) is connected to a third signal input terminal of the first regulating submodule (310), and a control terminal of the second regulating submodule (320) is connected to a switch tube driving terminal of the switching power supply (10); The first regulating submodule (310) is used to regulate the freewheeling tube of the switching power supply (10) to turn off according to the pulse width modulation signal, the clock signal and the regulating signal output by the signal regulating end of the second regulating submodule (320) when the input inductance energy of the switching power supply (10) is greater than the output inductance energy.

2. The switching power supply protection circuit based on forced continuous mode according to claim 1, characterized in that: The first regulating submodule (310) is further used to regulate the conduction of the freewheeling tube of the switching power supply (10) according to the pulse width modulation signal, the clock signal and the regulating signal output by the signal regulating end of the second regulating submodule (320); The second regulating submodule (320) is used to regulate the switching tube of the switching power supply (10) to be turned on or off according to the pulse width modulation signal, the clock signal and the regulating signal output by the signal regulating end of the first regulating submodule (310).

3. The switching power supply protection circuit based on forced continuous mode as claimed in claim 2, characterized in that: The first regulation submodule (310) comprises: A first inverter (3111), wherein an input end of the first inverter (3111) is connected to an output end of the pulse width modulation module (20); a first trigger (3112), wherein an input end of the first trigger (3112) is connected to an output end of the first inverter (3111), and a clock end of the first trigger (3112) is used to obtain a clock signal; a second inverter (3113), wherein an input end of the second inverter (3113) is connected to an output end of the first trigger (3112); a first OR operator (3114), wherein a first input terminal of the first OR operator (3114) is connected to an output terminal of the second inverter (3113); A first driver submodule (3115), wherein an input end of the first driver submodule (3115) is connected to an output end of the first OR operator (3114), and an output end of the first driver submodule (3115) is connected to a freewheeling tube driving end of the switching power supply (10).

4. The switching power supply protection circuit based on forced continuous mode as claimed in claim 3, characterized in that: The second regulation submodule (320) comprises: a first AND operator (3211), wherein a first input end of the first AND operator (3211) is connected to an output end of the first trigger (3112), and a second input end of the first AND operator (3211) is used to obtain the clock signal; a second trigger (3212), wherein a set end of the second trigger (3212) is connected to an output end of the first AND operator (3211), a reset end of the second trigger (3212) is connected to an output end of the pulse width modulation module (20), and an output end of the second trigger (3212) is connected to a second input end of the first OR operator (3114); A second driving submodule (3213), wherein an input end of the second driving submodule (3213) is connected to an output end of the second trigger (3212), and an output end of the second driving submodule (3213) is connected to a switch tube driving end of the switching power supply (10).

5. The switching power supply protection circuit based on forced continuous mode as claimed in claim 2, characterized in that: The first regulation submodule (310) comprises: a third inverter (3121), wherein an input end of the third inverter (3121) is connected to an output end of the pulse width modulation module (20); a third trigger (3122), wherein the input end of the third trigger (3122) is connected to the output end of the third inverter (3121), and the clock end of the third trigger (3122) is used to obtain a clock signal; a second AND operator (3123), wherein a first input terminal of the second AND operator (3123) is connected to an output terminal of the third trigger (3122); A third driver submodule (3124), wherein the input end of the third driver submodule (3124) is connected to the output end of the second AND operator (3123), and the output end of the third driver submodule (3124) is connected to the freewheeling tube driving end of the switching power supply (10).

6. The switching power supply protection circuit based on forced continuous mode according to claim 5, characterized in that: The second regulation submodule (320) comprises: a third AND operator (3221), wherein a first input terminal of the third AND operator (3221) is connected to an output terminal of the third trigger (3122), and a second input terminal of the third AND operator (3221) is used to obtain the clock signal; a fourth trigger (3222), wherein a set end of the fourth trigger (3222) is connected to the output end of the third AND operator (3221), and a reset end of the fourth trigger (3222) is connected to the output end of the pulse width modulation module (20); a fourth inverter (3223), wherein the input end of the fourth inverter (3223) is connected to the output end of the fourth trigger (3222), and the output end of the fourth inverter (3223) is connected to the second input end of the second AND operator (3123); A fourth driver submodule (3224), wherein the input end of the fourth driver submodule (3224) is connected to the output end of the fourth inverter (3223), and the output end of the fourth driver submodule (3224) is connected to the switch tube driving end of the switch power supply (10).

7. The switching power supply protection circuit based on the forced continuous mode according to any one of claims 1 to 6, characterized in that: The pulse width modulation module (20) comprises: A voltage division feedback module (210) connected to the output end of the switching power supply (10) and used to perform voltage division processing on the output voltage signal to obtain a voltage feedback signal; An operational amplifier module (220), connected to the voltage division feedback module (210), and configured to obtain a compensation voltage signal according to the voltage feedback signal and a reference voltage signal; A comparison module (230) is connected to the current sampling terminal of the switching power supply (10) and the operational amplifier module (220), and is used to output a pulse width modulation signal according to the current sampling signal and the compensation voltage signal.

8. The switching power supply protection circuit based on forced continuous mode according to claim 7, characterized in that: The voltage division feedback module (210) comprises: a first resistor (211), one end of the first resistor (211) being connected to an output end of the switching power supply (10); a second resistor (212), one end of the second resistor (212) being connected to the other end of the first resistor (211), and the other end of the second resistor (212) being grounded; The operational amplifier module (220) comprises: An operational amplifier (221), wherein an inverting input terminal of the operational amplifier (221) is connected to a common terminal of the first resistor (211) and the second resistor (212), and a non-inverting input terminal of the operational amplifier (221) is used to obtain a reference voltage.

9. The switching power supply protection circuit based on forced continuous mode according to claim 8, characterized in that: The comparison module (230) comprises: A comparator (231), wherein a non-inverting input terminal of the comparator (231) is connected to a current sampling terminal of the switching power supply (10) for obtaining the current sampling signal, an inverting input terminal of the comparator (231) is connected to an output terminal of the operational amplifier (221), and an output terminal of the comparator (231) serves as an output terminal of the pulse width modulation module (20) for outputting the pulse width modulation signal.

10. An electronic device, characterized in that: The invention comprises a switching power supply protection circuit based on a forced continuous mode as claimed in any one of claims 1 to 9.

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