Switching circuit and control method thereof

Abstract

The invention provides a switching circuit and a control method thereof. The switching circuit comprises a control module and a switching module, the control module comprises a first control circuit, a second control circuit and a logic control driving unit; the first control circuit is coupled with the switch module and is used for generating a first control signal according to a voltage signal of the switch module; the second control circuit is coupled with the switch module and is used for generating a second control signal according to the voltage signal of the switch module; the logic control driving unit is coupled with the switch module and used for controlling the switch module according to the first control signal or the second control signal. The switching circuit is used for achieving the effect of reducing circuit loss.

Description

Technical Field

[0001] The present application relates to the technical field of power supply control chips, and in particular to a switch circuit and a control method thereof. Background Art

[0002] In application scenarios that require efficient, reliable and controllable power conversion and distribution, switching circuits play a vital role in meeting the specific requirements of different devices for power supply voltage, ensuring stable operation of the equipment and improving the energy efficiency of the overall system.

[0003] In the related art, the boost switching circuit usually uses two alternately conducting switching elements to control the charging and discharging process of the inductor, thereby achieving a voltage boost. When switching element 1 is turned on, switching element 2 is turned off, and the input power charges the inductor connected in series in the circuit through switching element 1, and the inductor stores energy. When switching element 2 is turned on, switching element 1 is turned off, and the inductor releases the previously stored energy and supplies power to the output end to maintain the stability of the output voltage. This alternating conduction working mode ensures continuous voltage boost and stable output.

[0004] However, the above switch circuit has relatively large loss during operation. Summary of the invention

[0005] The embodiments of the present application provide a switching circuit and a control method thereof, so as to achieve the effect of reducing the loss of the switching circuit.

[0006] In a first aspect, an embodiment of the present application provides a switch circuit, comprising: a control module and a switch module; the control module comprises a first control circuit, a second control circuit and a logic control drive unit;

[0007] The first control circuit is coupled to the switch module and is used to generate a first control signal according to the voltage signal of the switch module;

[0008] The second control circuit is coupled to the switch module and is used to generate a second control signal according to the voltage signal of the switch module;

[0009] The logic control driving unit is coupled to the switch module, and is used to control the switch module according to the first control signal or the second control signal.

[0010] In a possible implementation, the switch module includes a first switch tube, a second switch tube, and an inductor;

[0011] The first end of the inductor is connected to the input end of the switch module, and the second end of the inductor is connected to one end of the first switch tube;

[0012] One end of the first switch tube is connected to one end of the second switch tube, the other end of the first switch tube is grounded, and the other end of the second switch tube is connected to the output end of the switch module;

[0013] The first control circuit is used to generate a first control signal according to the source voltage of the first switch tube, the voltage at the connection point between the first switch tube and the second switch tube, and the output voltage of the switch module.

[0014] In a possible implementation, the first control circuit includes a first comparison unit, a first inversion unit, and a first logic unit;

[0015] A first input terminal of the first logic unit is connected to an output terminal of the first inverting unit;

[0016] The second input terminal of the first logic unit is connected to the output terminal of the first comparison unit;

[0017] A first logic unit, configured to generate a first control signal according to an AND signal of the first inverting unit and the first comparing unit;

[0018] The output terminal of the first logic unit is connected to the first input terminal of the logic control driving unit.

[0019] In a possible implementation, the first comparison unit includes a first comparator;

[0020] The positive input signal of the first comparator is the voltage at the connection point between the first switch tube and the second switch tube;

[0021] The negative input signal of the first comparator is the output voltage of the switch module;

[0022] An output terminal of the first comparator is connected to a second input terminal of the first logic unit;

[0023] The input signal of the first inverting unit is the source voltage of the first switch tube.

[0024] In a possible implementation, the logic control driving unit is used to control the second switch tube to be turned on according to the first control signal.

[0025] In a possible implementation manner, the switch module further includes a resistor;

[0026] The first end of the resistor is connected to the input end of the switch module;

[0027] The second end of the resistor is connected to the first end of the inductor;

[0028] The second control circuit is used to generate a second control signal according to the source voltage of the first switch tube, the source voltage of the second switch tube, the voltage at the first end of the resistor and the voltage at the second end of the resistor.

[0029] In a possible implementation, the second control circuit includes a second comparison unit, a second inversion unit, and a second logic unit;

[0030] The first input terminal of the second logic unit is connected to the output terminal of the second inverting unit;

[0031] The second input terminal of the second logic unit is connected to the output terminal of the second comparison unit;

[0032] A second logic unit, used for generating a second control signal according to an AND signal of the second inverting unit and the second comparing unit;

[0033] The output end of the second logic unit is connected to the second input end of the logic control driving unit.

[0034] In a possible implementation, the second comparison unit includes a second comparator;

[0035] The positive input signal of the second comparator is the voltage of the first end of the resistor;

[0036] The negative input signal of the second comparator is the voltage of the second end of the resistor;

[0037] An output terminal of the second comparator is connected to a second input terminal of the first logic unit;

[0038] The input signal of the second inverting unit is the source voltage of the first switch tube.

[0039] In a possible implementation, the logic control driving unit is used to control the second switch tube to turn off according to the second control signal.

[0040] In a second aspect, an embodiment of the present application provides a switch circuit control method, which is applied to the switch circuit in any of the above embodiments, and the method includes:

[0041] The first control circuit of the control module generates a first control signal according to the voltage signal of the switch module, and the second control circuit of the control module generates a second control signal according to the voltage signal of the switch module;

[0042] The logic control driving unit of the control module controls the switch module according to the first control signal or the second control signal.

[0043] The switch circuit and control method thereof provided by the embodiment of the present application, the switch circuit includes a control module and a switch module; the control module includes a first control circuit, a second control circuit and a logic control drive unit; the first control circuit is coupled to the switch module, and is used to generate a first control signal according to a voltage signal of the switch module; the second control circuit is coupled to the switch module, and is used to generate a second control signal according to the voltage signal of the switch module; the logic control drive unit is coupled to the switch module, and is used to control the switch module according to the first control signal or the second control signal. The switch circuit achieves the effect of reducing circuit loss by controlling the on and off of the switch module. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0045] Figure 1 The structure of the switch circuit provided in this application is shown in FIG. Figure 1 ;

[0046] Figure 2 The control signal and inductor current signal provided in this application are shown in FIG. Figure 1 ;

[0047] Figure 3 The structure of the switch circuit provided in this application is shown in FIG. Figure 2 ;

[0048] Figure 4 The structure of the switch circuit provided in this application is shown in FIG. Figure 3 ;

[0049] Figure 5 A schematic diagram of the structure of the first control circuit provided in this application;

[0050] Figure 6 The structure of the switch circuit provided in this application is shown in FIG. Figure 4 ;

[0051] Figure 7 A schematic diagram of the structure of the second control circuit provided in this application;

[0052] Figure 8 The control signal and inductor current signal provided in this application are shown in FIG. Figure 2 ;

[0053] Fig. 9 A schematic flow chart of a switch circuit control method provided in the present application.

[0054] Reference numerals

[0055] 10. Control module;

[0056] 11. a first control circuit; 111. a first comparison unit; 112. a first inversion unit; 113. a first logic unit;

[0057] 12. a second control circuit; 121. a second comparison unit; 122. a second inversion unit; 123. a second logic unit;

[0058] 13. Logic control drive unit;

[0059] 20. Switch module; Q1. first switch tube; Q2. second switch tube; L. inductor; C. capacitor; R. resistor.

[0060] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0061] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0062] Switching circuits play a vital role in the field of power electronics, especially in application scenarios that require efficient, reliable and controllable power conversion and distribution. Switching circuits can meet the specific requirements of different devices for power supply voltage. This is crucial to ensure the stable operation of the equipment and improve the energy efficiency of the overall system.

[0063] Figure 1 The structure of the switch circuit provided in this application is shown in FIG. Figure 1 .like Figure 1 As shown in the figure, in the boost switch circuit (Boost) in the related art, the switch tubes Q1 and Q2 are turned on alternately. When Q1 is turned on, Q2 is turned off, and the input power charges the inductor L through Q1, and the inductor stores energy. When Q2 is turned on, Q1 is turned off, and the inductor releases the previously stored energy to supply power to the output end and charge the output capacitor at the same time, thereby maintaining the stability of the output voltage. In this process, when Q1 is turned off, Q2 will be turned on immediately, V SW Equal to V IN , due to V OUT Higher than V IN , so when Q2 is turned on, there will be a source-drain voltage difference V ds At the same time, since the inductor current cannot change suddenly, there will be current in Q2 during the conduction process, resulting in Q2 switching loss and output voltage V OUT Ratio input voltage V IN The higher it is, the greater the switching loss; the higher the switching frequency, the higher the switching loss and the lower the efficiency of the switching circuit for DC-DC conversion.

[0064] In addition to the above switching losses, low light load efficiency is also one of the main problems of current switching circuits. In the process of the control chip controlling the switching circuit, the control signal and the inductor current signal are as follows: Figure 2 As shown, Q1-Gate is the gate drive signal of Q1, Q2-Gate is the gate drive signal of Q2, and IL is the inductor current. When the load is very light or no-load, the inductor current flows in the reverse direction and the capacitor C discharges in the reverse direction, that is, Figure 2 Middle I L In the dotted part, the excess energy in the inductor cannot be effectively utilized, but is wasted through reverse discharge and additional losses. The additional current and voltage difference loss when Q2 is turned off further reduce the performance and efficiency of the circuit. When the load is suddenly pulled, due to insufficient inductor energy reserves and delayed charging process, the inductor current needs to be charged to the forward direction first, and then discharged to the output after the forward direction increases to a certain extent, resulting in fluctuations in the output voltage and performance degradation. In other words, the smaller the load of the switching circuit, the greater the proportion of the circuit's own power consumption, and the lower the circuit efficiency.

[0065] In response to the above-mentioned problems, the switching circuit and control method provided in the present application, by setting a control module for the switching circuit, controls the on and off of the switching tube in the switching circuit according to the voltage signals at multiple positions in the switching circuit, thereby reducing the switching loss and the loss caused by light load / no load, and improving the circuit performance.

[0066] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0067] Figure 3 The structure of the switch circuit provided in this application is shown in FIG. Figure 2 .like Figure 3 As shown, the switch circuit includes: a control module 10 and a switch module 20 ; the control module 10 includes a first control circuit 11 , a second control circuit 12 and a logic control drive unit 13 .

[0068] The first control circuit 11 is coupled to the switch module 20 and is used to generate a first control signal according to a voltage signal of the switch module 20 .

[0069] The second control circuit 12 is coupled to the switch module 20 and is configured to generate a second control signal according to the voltage signal of the switch module 20 .

[0070] The logic control driving unit 13 is coupled to the switch module 20 and is used to control the switch module 20 according to the first control signal or the second control signal.

[0071] Specifically, the first control circuit 11 generates a first control signal by collecting the voltage signal in the switch module 20 according to the voltage signal and the control logic in the first control circuit 11. The logic control driving unit 13 controls the on or off of the switch element in the switch module 20 according to the first control signal. It should be understood that the voltage signal collected by the first control circuit 11 from the switch module 20 is a voltage signal at multiple positions in the switch module 20. The first control circuit 11 can process the collected voltage signal according to its hardware control logic, such as performing level inversion, voltage size comparison, etc., and finally output the first control signal to the logic control driving unit 13.

[0072] The second control circuit 12 generates a second control signal by collecting the voltage signal in the switch module 20 according to the voltage signal and the control logic in the second control circuit 12. The logic control driving unit 13 controls the on or off of the switch element in the switch module 20 according to the second control signal. It should be understood that the voltage signal collected by the second control circuit 12 from the switch module 20 is a voltage signal at multiple positions in the switch module 20. The second control circuit 12 can process the collected voltage signal according to its hardware control logic, such as performing level inversion, voltage size comparison, etc., and finally output the second control signal to the logic control driving unit 13.

[0073] Optionally, the first control circuit 11 and the second control circuit 12 can function at different stages of the switch circuit operation. For example, when the first switch element in the switch module 20 is turned on and the second switch element is turned off, the first control circuit 11 outputs a first control signal according to the voltage signal; when the first switch element in the switch module 20 is turned off and the second switch element is turned on, the second control circuit 12 outputs a second control signal according to the voltage signal.

[0074] Optionally, the first control circuit 11 and the second control circuit 12 may also function at the same stage of the switch circuit operation. For example, when the first switch element in the switch module 20 is turned off and the second switch element is turned off, the first control circuit 11 outputs a first control signal according to the voltage signal to control the first switch element to be turned on; when the first switch element in the switch module 20 is turned off and the second switch element is turned off, the second control circuit 12 outputs a second control signal according to the voltage signal to control the second switch element to be turned on.

[0075] The switching circuit provided in this embodiment processes the voltage signal in the switching module 20 according to the control logic in the control module 10, and generates a control signal, which reacts to the switching module 20. By setting the control logic, the switching module 20 can be controlled when the circuit generates losses, thereby achieving the effect of reducing losses, improving the performance of the switching circuit and the conversion efficiency of the switching circuit in converting voltage.

[0076] Figure 4 The structure of the switch circuit provided in this application is shown in FIG. Figure 3 .like Figure 4 As shown, the switch module 20 includes a first switch tube Q1 , a second switch tube Q2 , and an inductor L.

[0077] A first end of the inductor L is connected to the input end of the switch module 20 , and a second end of the inductor L is connected to one end of the first switch tube Q1 .

[0078] One end of the first switch tube Q1 is connected to one end of the second switch tube Q2 , the other end of the first switch tube Q1 is grounded, and the other end of the second switch tube Q2 is connected to the output end of the switch module 20 .

[0079] The first control circuit 11 is used to generate a first control signal according to the source voltage of the first switch tube Q1 , the voltage at the connection point between the first switch tube Q1 and the second switch tube Q2 , and the output voltage of the switch module 20 .

[0080] from Figure 4 It can be seen from the figure that the structure of the switch module 20 in this embodiment is similar to Figure 1 Based on this structure, the first input terminal of the first control circuit 11 of this embodiment is connected to the source of the first switch tube Q1, so as to obtain the source voltage V G1 The second input terminal of the first control circuit 11 is connected to the drain of the first switch tube Q1, and is used to obtain the voltage V at the connection point between the first switch tube Q1 and the second switch tube Q2. SW The third input terminal of the first control circuit 11 is connected to the output terminal of the switch module 20, and is used to obtain the output voltage V of the switch module 20. OUT .

[0081] In this embodiment, when the first switch tube Q1 is turned off, the second switch tube Q2 is not turned on first. The first control circuit 11 generates a first control signal according to the source voltage of the first switch tube Q1, the voltage at the connection point between the first switch tube Q1 and the second switch tube Q2, and the output voltage of the switch module 20. After receiving the first control signal, the logic control driving unit 13 controls the second light-opening tube to turn on, thereby reducing the switching loss caused by immediately turning on the second switch tube Q2 when the first switch tube Q1 is turned off, and improving the overall performance of the circuit.

[0082] Figure 5 Schematic diagram of the structure of the first control circuit 11 provided in this application. Figure 5 As shown, the first control circuit 11 includes a first comparing unit 111 , a first inverting unit 112 and a first logic unit 113 .

[0083] A first input terminal of the first logic unit 113 is connected to an output terminal of the first inverting unit 112;

[0084] A second input terminal of the first logic unit 113 is connected to an output terminal of the first comparison unit 111;

[0085] A first logic unit 113, configured to generate a first control signal according to an AND signal of the first inverting unit 112 and the first comparing unit 111;

[0086] The output terminal of the first logic unit 113 is connected to the first input terminal of the logic control driving unit 13 .

[0087] For example, when the voltage signals output by the first inverting unit 112 and the first comparing unit 111 are both at high levels, the first control signal is used to instruct to convert the low level of the switch tube into a high level.

[0088] Optionally, the first comparing unit 111 includes a first comparator.

[0089] The positive input signal of the first comparator is the voltage V at the connection point between the first switch tube Q1 and the second switch tube Q2. SW The negative input signal of the first comparator is the output voltage V of the switch module 20. OUT ; The output terminal of the first comparator is connected to the second input terminal of the first logic unit 113.

[0090] The input signal of the first inverting unit 112 is the source voltage V of the first switch tube Q1. G1 .

[0091] In a possible implementation, the logic control driving unit 13 is used to control the second switch tube Q2 to be turned on according to the first control signal.

[0092] In this embodiment, when the first switch tube Q1 is turned off, V G1 is low level, at this time, the inductor L is fully charged, and the second switch tube Q2 is not turned on yet. The inductor L starts to charge the parasitic capacitance of the first switch tube Q1, V SW Starts to climb. When V SW Voltage greater than or equal to V OUT When the first comparison unit 111 outputs a high level, and V G1 After passing through the NOT gate, the voltage is high. At this time, the first logic unit 113 outputs the first control signal at a high level, which is used to control the second switch tube Q2 to turn on, and the inductor L starts to supply energy to the output. In the process from the first switch tube Q1 being turned off to the second switch tube Q2 being turned on, the source-drain voltage difference V ds It is almost close to 0V, so the second switch tube Q2 can achieve zero voltage conduction, and the switching loss is almost zero, thereby improving the performance of the switching circuit.

[0093] Figure 6 The structure of the switch circuit provided in this application is shown in FIG. Figure 4 .like Figure 6 As shown, in Figure 1 Based on the structure of the switch circuit shown, the switch module 20 of this embodiment further includes a resistor R.

[0094] A first end of the resistor R is connected to an input end of the switch module 20 ; a second end of the resistor R is connected to a first end of the inductor L.

[0095] The second control circuit 12 is used to generate a second control signal according to the source voltage of the first switch tube Q1, the source voltage of the second switch tube Q2, the voltage at the first end of the resistor R, and the voltage at the second end of the resistor R.

[0096] The resistor R in this embodiment is a current sensing resistor R, which is used to detect the voltage V across the inductor L. R- and V R+ Based on the structure of the switch module 20, the first input terminal of the second control circuit 12 of this embodiment is connected to the source of the first switch tube Q1 to obtain the source voltage V G1 The second input terminal of the second control circuit 12 is connected to the source of the second switch tube Q2, and is used to obtain the source voltage V of the second switch tube Q2. G2 The third input terminal of the second control circuit 12 is connected to the first terminal of the resistor R, and is used to obtain the voltage V at the first terminal of the resistor R. R- The fourth input terminal of the second control circuit 12 is connected to the second end of the resistor R, and is used to obtain the voltage V at the second end of the resistor R. R+ .

[0097] In this embodiment, after the second switch tube Q2 is turned on, the second control circuit 12 generates a second control signal according to the source voltage of the first switch tube Q1, the source voltage of the second switch tube Q2, the voltage at the first end of the resistor R, and the voltage at the second end of the resistor R. After receiving the second control signal, the logic control driving unit 13 controls the second switch tube Q2 to be turned off, thereby reducing the switching loss generated during the turn-off process of the second switch tube Q2 and improving the overall performance of the circuit.

[0098] Figure 7 Schematic diagram of the structure of the second control circuit 12 provided in this application. Figure 7 As shown, the second control circuit 12 includes a second comparing unit 121 , a second inverting unit 122 and a second logic unit 123 .

[0099] A first input terminal of the second logic unit 123 is connected to an output terminal of the second inverting unit 122;

[0100] A second input terminal of the second logic unit 123 is connected to an output terminal of the second comparison unit 121;

[0101] A second logic unit 123, configured to generate a second control signal according to an AND signal of the second inverting unit 122 and the second comparing unit 121;

[0102] The output terminal of the second logic unit 123 is connected to the second input terminal of the logic control driving unit 13 .

[0103] For example, when the voltage signals output by the second inverting unit 122 and the second comparing unit 121 are both at a high level, the second control signal is used to instruct to convert the high level of the switch tube into a low level.

[0104] Optionally, the second comparing unit 121 includes a second comparator.

[0105] The positive input signal of the second comparator is the voltage of the first end of the resistor R;

[0106] The negative input signal of the second comparator is the voltage at the second end of the resistor R;

[0107] The output terminal of the second comparator is connected to the second input terminal of the first logic unit 113;

[0108] The input signal of the second inverting unit 122 is the source voltage of the first switch tube Q1 .

[0109] In a possible implementation manner, the logic control driving unit 13 is used to control the second switch tube Q2 to be turned off according to the second control signal.

[0110] Combination Figure 7 , Figure 8 , V R+ Greater than V R- , it means that the current of inductor L is positive, V R+ Less than V R- This means that the current in the inductor L is negative. When the first switch tube Q1 is turned off and the second switch tube Q2 is turned on (corresponding to Figure 8 At t1 in the G1 is low level, V G2 is high level, at this time, the inductor L supplies power to the output, the inductor L current is a positive current and gradually decreases, and when the inductor L current decreases to 0A, V R+ Equal to V R- . Since V OUT Greater than V IN , the inductor L current will continue to decrease and become a negative current. At this time, V G1After passing through the NOT gate, the second comparison unit 121 outputs a high level, and the second logic unit 123 outputs a second control signal of a high level, which is used to control the second switch tube Q2 to turn off (corresponding to Figure 8 At t2 in the figure). At t2, the current of the inductor L does not generate negative current, and the valley current is clamped to nearly 0A. At this time, the second switch tube Q2 is turned off, and the current I between the source and gate of the second switch tube Q2 ds The current of the second switch tube Q2 is about 0A, which realizes the zero current shutdown of the second switch tube Q2, reduces the switching loss in the shutdown process, and thus improves the efficiency of the entire circuit. Compared with the prior art, the shutdown time of the second switch tube Q2 is advanced from time t3 to time t2, so that the current of the inductor L will not generate negative current during the process from time t2 to the next cycle when the first switch tube Q1 is turned on, thereby reducing the switching loss.

[0111] The present application also provides a switch circuit control method, which is applied to the switch circuit in any of the above embodiments, and the method includes:

[0112] The first control circuit 11 of the control module 10 generates a first control signal according to the voltage signal of the switch module 20, and the second control circuit 12 of the control module 10 generates a second control signal according to the voltage signal of the switch module 20;

[0113] The logic control driving unit 13 of the control module 10 controls the switch module 20 according to the first control signal or the second control signal.

[0114] like Fig. 9 As shown, in combination with the above-mentioned embodiment of the switch circuit, the control module 10 is used as the execution body, and the method of this embodiment includes the following steps:

[0115] S301, receiving a power-on command.

[0116] S302, control V G1 is high level, the first switch tube Q1 is turned on.

[0117] S303 , detecting a voltage signal of the switch module 20 .

[0118] S304, determine V G1 Is it low level, V SW Is ≥V OUT If yes, go to step S305, if no, go to step S303.

[0119] S305, output the first control signal to control V G2 is high level, and the second switch tube Q2 is turned on.

[0120] S306, determine V G1 Is it low level, V G2Is it high level, V R- Is ≥V R+ If yes, go to step S307, if no, go to step S305.

[0121] S307, output the second control signal to control V G2 is at a low level, and the second switch tube Q2 is turned off.

[0122] S308: Determine whether to power off. If yes, execute step S309; ​​if no, execute step S302.

[0123] S309 , the first switch tube Q1 and the second switch tube Q2 are turned off at the same time, and the power is turned off.

[0124] The switch circuit control method provided in this embodiment has a similar implementation principle and technical effect to the description of the above-mentioned embodiment. In the process of the first switch tube Q1 being turned off and the second switch tube Q2 being turned on, the source-drain voltage difference V of the second switch tube Q2 is realized. ds is zero, that is, the second switch tube Q2 is turned on by zero voltage; during the process of the second switch tube Q2 being turned off, the current I in the second switch tube Q2 is realized ds The second switch tube Q2 is turned off by zero current, which saves the switching loss during the turn-on and turn-off of the second switch tube Q2, thereby improving the performance and voltage conversion efficiency of the entire switch circuit topology.

[0125] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A switching circuit, characterized in that: include: A control module and a switch module; the control module includes a first control circuit, a second control circuit and a logic control drive unit; The first control circuit is coupled to the switch module and is used to generate a first control signal according to the voltage signal of the switch module; The second control circuit is coupled to the switch module and is used to generate a second control signal according to the voltage signal of the switch module; The logic control driving unit is coupled to the switch module, and is used to control the switch module according to the first control signal or the second control signal.

2. The switch circuit according to claim 1, characterized in that: The switch module includes a first switch tube, a second switch tube, and an inductor; The first end of the inductor is connected to the input end of the switch module, and the second end of the inductor is connected to one end of the first switch tube; One end of the first switch tube is connected to one end of the second switch tube, the other end of the first switch tube is grounded, and the other end of the second switch tube is connected to the output end of the switch module; The first control circuit is used to generate a first control signal according to the source voltage of the first switch tube, the voltage at the connection point between the first switch tube and the second switch tube, and the output voltage of the switch module.

3. The switch circuit according to claim 2, characterized in that: The first control circuit includes a first comparison unit, a first inversion unit and a first logic unit; The first input terminal of the first logic unit is connected to the output terminal of the first inverting unit; The second input terminal of the first logic unit is connected to the output terminal of the first comparison unit; The first logic unit is used to generate a first control signal according to an AND signal of the first inverting unit and the first comparing unit; The output end of the first logic unit is connected to the first input end of the logic control driving unit.

4. The switch circuit according to claim 3, characterized in that: The first comparison unit includes a first comparator; The positive input signal of the first comparator is the voltage at the connection point between the first switch tube and the second switch tube; The negative input signal of the first comparator is the output voltage of the switch module; The output terminal of the first comparator is connected to the second input terminal of the first logic unit; The input signal of the first inverting unit is the source voltage of the first switch tube.

5. The switch circuit according to any one of claims 2 to 4, characterized in that: The logic control driving unit is used to control the second switch tube to be turned on according to the first control signal.

6. The switch circuit according to claim 2, characterized in that: The switch module also includes a resistor; The first end of the resistor is connected to the input end of the switch module; The second end of the resistor is connected to the first end of the inductor; The second control circuit is used to generate a second control signal according to the source voltage of the first switch tube, the source voltage of the second switch tube, the voltage at the first end of the resistor, and the voltage at the second end of the resistor.

7. The switch circuit according to claim 6, characterized in that: The second control circuit includes a second comparison unit, a second inversion unit and a second logic unit; The first input terminal of the second logic unit is connected to the output terminal of the second inverting unit; The second input terminal of the second logic unit is connected to the output terminal of the second comparison unit; The second logic unit is used to generate a second control signal according to an AND signal of the second inverting unit and the second comparing unit; The output end of the second logic unit is connected to the second input end of the logic control driving unit.

8. The switch circuit according to claim 7, characterized in that: The second comparison unit includes a second comparator; The positive input signal of the second comparator is the voltage of the first end of the resistor; The negative input signal of the second comparator is the voltage of the second end of the resistor; The output terminal of the second comparator is connected to the second input terminal of the first logic unit; The input signal of the second inverting unit is the source voltage of the first switch tube.

9. The switch circuit according to any one of claims 6 to 8, characterized in that: The logic control driving unit is used to control the second switch tube to turn off according to the second control signal.

10. A switch circuit control method, characterized in that: Applied to the switch circuit according to any one of claims 1 to 9, the method comprising: The first control circuit of the control module generates a first control signal according to the voltage signal of the switch module, and the second control circuit of the control module generates a second control signal according to the voltage signal of the switch module; The logic control driving unit of the control module controls the switch module according to the first control signal or the second control signal.

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