Surge protection circuit and charging circuit

Abstract

The utility model relates to the technical field of power electronics, and discloses a surge protection circuit and a charging circuit, the surge protection circuit comprises a first surge module and a second surge module which are connected in parallel, and the absolute value of the negative clamping voltage of the second surge module is lower than the absolute value of the negative clamping voltage of the first surge module. When the clamping voltage of the positive surge of the first surge module is low, but the clamping voltage of the negative surge is high, the second surge module is added, and when the absolute value of the negative surge voltage is higher than the absolute value of the negative clamping voltage of the second surge module and the absolute value of the negative clamping voltage of the first surge module, the second surge module is added. And the second surge module can clamp the surge voltage, so that the clamping voltage during negative surge can be effectively reduced, and other module circuits are protected.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of power electronics, concretely relates to a surge protection circuit and charging circuit. BACKGROUND

[0002] In some power supply or signal circuit, surge often appears, and the surge is caused by switch and lightning transient overvoltage, and the appearance of the surge can cause abnormal work of the equipment in the circuit or even damage. In the related art, a surge module is often connected in parallel in front of the power supply or signal circuit, and the surge module can be used for absorbing the power supply surge voltage, or used for protecting other electronic devices connected to the power supply circuit from the surge voltage, or mainly used for protecting the communication interface. However, since only one surge module is used in the related art, the negative surge capacity level of this arrangement is low, and a higher level capacity cannot be achieved. SUMMARY

[0003] Therefore, the utility model provides a kind of surge protection circuit and charging circuit to solve the problem of how to improve negative surge capacity.

[0004] In a first aspect, the utility model provides a kind of surge protection circuit, comprising: the first surge module and the second surge module connected in parallel, wherein the first input end of first surge module inputs positive voltage, the second input end of first surge module inputs negative voltage, and the second input end of first surge module is grounded;The first input end of second surge module inputs positive voltage, the second input end of second surge module inputs negative voltage, and the second input end of second surge module is grounded;The positive surge clamping voltage of second surge module is higher than the positive clamping voltage of first surge module, and the negative clamping voltage of second surge module is lower than the negative clamping voltage of first surge module.

[0005] In the utility model, the positive surge clamping voltage of first surge module is low, but the clamping voltage of negative surge is relatively high, the second surge module is increased, the absolute value of the negative clamping voltage of second surge module is less than the absolute value of the negative clamping voltage of first surge module, when the absolute value of negative surge voltage is between the absolute value of the negative clamping voltage of second surge module and the absolute value of the negative clamping voltage of first surge module, second surge module can clamp surge voltage, so that the clamping voltage when negative surge can be effectively reduced, and other module circuits are protected.

[0006] In an alternative embodiment, the first surge module comprises a first surge tube, wherein the cathode of the first surge tube inputs positive voltage, the anode of the first surge tube inputs negative voltage, and the anode of the first surge tube is also grounded.

[0007] In an alternative embodiment, the second surge module comprises: a second surge tube, wherein a cathode of the second surge tube inputs a positive voltage, an anode of the second surge tube inputs a negative voltage, and the anode of the second surge tube is also connected to ground; and an absolute value of a negative clamping voltage of the second surge tube is lower than an absolute value of a negative clamping voltage of the first surge tube.

[0008] In a second aspect, the utility model provides a charging circuit, comprising: the surge protection circuit and direct current voltage conversion circuit of first aspect and any alternative embodiment, wherein the input end of direct current voltage conversion circuit is connected with the first input end of second surge module, and the output end of direct current voltage conversion circuit is connected with load.

[0009] In an alternative embodiment, the direct current voltage conversion circuit comprises: a DC-DC circuit and a control circuit, wherein the input end of the DC-DC circuit is connected with the first input end of the second surge module, and the output end of the DC-DC circuit is connected with the load; the first input end of the control circuit is connected with the input end of the DC-DC circuit, the second input end of the control circuit is connected with the output end of the DC-DC circuit, the third input end of the control circuit inputs a control command, and the output end of the control circuit is connected with the control end of the DC-DC circuit.

[0010] In an alternative embodiment, the DC-DC circuit comprises: a voltage conversion chip circuit, wherein the input end of the voltage conversion chip circuit is connected with the first input end of the second surge module and the first input end of the control circuit, the output end of the voltage conversion chip circuit is connected with the second input end of the control circuit and the load, and the control end of the voltage conversion chip circuit is connected with the output end of the control circuit.

[0011] In an alternative embodiment, the DC-DC circuit further comprises: a filter circuit, wherein the input end of the filter circuit is connected with the output end of the voltage conversion chip circuit, and the output end of the filter circuit is connected with the load.

[0012] In an alternative embodiment, the filter circuit comprises: a plurality of capacitors connected in parallel.

[0013] In an alternative embodiment, the control circuit comprises: an MCU logic control chip. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the specific embodiments of the utility model or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the description of the specific embodiments or the prior art. Obviously, the drawings described below are some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0015] Figure 1 is a component diagram of a surge protection circuit according to an embodiment of the present application;

[0016] Figure 2 is a specific circuit structure diagram of a surge protection circuit according to an embodiment of the present application;

[0017] Figure 3 is a component diagram of a charging circuit according to an embodiment of the present application;

[0018] Figure 4 is a component diagram of another charging circuit according to an embodiment of the present application;

[0019] Figure 5 is a specific circuit structure diagram of a DC-DC circuit according to an embodiment of the present application;

[0020] Figure 6 is a schematic diagram of an MCU logic control chip according to an embodiment of the present application;

[0021] Figure 7 is a schematic diagram of an interface module according to an embodiment of the present application.

[0022] Reference signs:

[0023] 1 - surge protection circuit; 2 - direct current voltage conversion circuit; 11 - first surge module; 12 - second surge module; TVS1 - first surge tube; TVS2 - second surge tube; 21 - DC-DC circuit; 22 - control circuit. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0025] In the description of the present application, it should be noted that the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0028] This embodiment provides a surge protection circuit 1, such as Figure 1 As shown, it includes a first surge module 11 and a second surge module 12 connected in parallel. The first input terminal of the first surge module 11 receives a positive voltage (Vbus+), the second input terminal of the first surge module 11 receives a negative voltage (Vbus-), and the second input terminal of the first surge module 11 is grounded; the first input terminal of the second surge module 12 receives a positive voltage, the second input terminal of the second surge module 12 receives a negative voltage, and the second input terminal of the second surge module 12 is grounded.

[0029] Specifically, Figure 1 The two surge modules are connected in parallel. The first end of the second surge module 12 can be connected to the communication interface or the input end of the DC-DC circuit 21. The two surge modules work together to absorb surge current and suppress surge voltage.

[0030] Specifically, the charging circuits currently using DC-DC circuit 21 often only have a first surge module 11. Since the surge capability of the first surge module 11 is low, for example, the surge capability of the first surge module 11 is less than 100V, while the surge voltage in actual testing is often higher than 100V, setting only the first surge module 11 will damage DC-DC circuit 21 or other module circuits.

[0031] To address the issue of low surge capability due to having only one surge module, this embodiment sets up two surge modules connected in parallel. The absolute value of the negative clamping voltage of the second surge module 12 is lower than the absolute value of the negative clamping voltage of the first surge module 11.

[0032] Specifically, in the case that the forward surge clamping voltage of the first surge module 11 is low, due to the limitation of the surge voltage protection range, the negative surge clamping voltage of the first surge module 11 is relatively high. By adding the second surge module 12, the second surge module 12 internally has a device with a low negative surge clamping voltage, i.e., the absolute value of the negative clamping voltage of the second surge module 12 is lower than that of the first surge module 11. For example, the negative clamping voltage of the first surge module 11 is -100V, and the negative clamping voltage of the second surge module 12 is -50V, i.e., the absolute value of the negative clamping voltage of the first surge module is higher than that of the second surge module. When the negative voltage is -70V, if only the first surge module exists, there will still be a surge condition. However, since the negative clamping voltage of the second surge module 12 is -50V, the negative voltage will be clamped, thereby effectively reducing the clamping voltage during negative surge and protecting other module circuits.

[0033] Optionally, without considering the cost, multiple surge modules can be provided, and the absolute values of the negative clamping voltages of the surge modules decrease in turn, thereby achieving multi-stage clamping of the surge voltage.

[0034] In some optional embodiments, as shown in FIG. 1, Figure 2 The first surge module 11 includes a first surge tube TVS1, wherein the cathode of the first surge tube TVS1 inputs a positive voltage, the anode of the first surge tube TVS1 inputs a negative voltage, and the anode of the first surge tube TVS1 is also connected to the ground. The second surge module 12 includes a second surge tube TVS2, wherein the cathode of the second surge tube TVS2 inputs a positive voltage, the anode of the second surge tube TVS2 inputs a negative voltage, and the anode of the second surge tube TVS2 is also connected to the ground; and the absolute value of the negative clamping voltage of the second surge tube is lower than that of the first surge tube.

[0035] Specifically, a TVS (TRANSIENT VOLTAGE SUPPRESSOR) or a transient voltage suppression diode is a new product developed on the basis of a voltage stabilizing tube process. Its circuit symbol is the same as that of a common voltage stabilizing diode, and its appearance is also the same as that of a common diode. When the TVS tube is subjected to a transient high-energy impact, it can suddenly reduce its impedance at a very high speed (up to 1*10^-12 seconds), simultaneously absorb a large current, and clamp the voltage between its two ends to a predetermined value, thereby ensuring that the following circuit elements are not damaged by the transient high-energy impact.

[0036] Optionally, both surge tubes are back-scan surge tubes. Compared with conventional surge tubes, the clamping voltage of the back-scan surge tube is lower than that of the conventional surge tube, can release energy in advance, greatly protects the safety of the entire circuit, and effectively reduces the residual voltage value of the back end.

[0037] A charging circuit is provided in the embodiment, as shown in the figure, comprising: the surge protection circuit 1 and the direct current voltage conversion circuit 2 of the above embodiments and any optional implementation thereof. The input ends of the direct current voltage conversion circuit are respectively connected with the first ends of the second surge module 12, and the output end of the direct current voltage conversion circuit is connected with the load. Figure 3

[0038] Specifically, two surge modules are added in front of the direct current voltage conversion circuit 2, so as to realize the ability of absorbing surge current and suppressing surge voltage. The direct current voltage conversion circuit 2 can perform amplitude transformation on the input direct current voltage, so as to adapt to the charging voltage level of the load.

[0039] In some optional implementation, as shown in the figure, the direct current voltage conversion circuit 2 comprises: a DC-DC circuit 21 and a control circuit 22, wherein the input ends of the DC-DC circuit 21 are respectively connected with the first input ends of the second surge module 12, and the output end of the DC-DC circuit 21 is connected with the load; the first input end of the control circuit 22 is connected with the input end of the DC-DC circuit 21, the second input end of the control circuit 22 is connected with the output end of the DC-DC circuit 21, the third input end of the control circuit 22 inputs a control command, and the output end of the control circuit 22 is connected with the control end of the DC-DC circuit 21. Figure 4

[0040] Specifically, the DC-DC circuit 21 can realize the function of converting direct current voltage into direct current voltage, and the control circuit 22 can adjust the amplitude of the output voltage by controlling the duty cycle of the internal switch tube of the DC-DC circuit 21 based on the control command. After the DC-DC circuit 21 is stabilized, the control circuit 22 dynamically adjusts the duty cycle of the switch tube by collecting the input voltage and output voltage of the DC-DC circuit 21, so as to realize constant voltage output.

[0041] Optionally, the DC-DC circuit 21 can be a boost circuit, a buck circuit, a buck-boost circuit or a switching power supply, and the switching power supply can be composed of a flyback circuit. The control circuit 22 is built-in with a driving circuit which can drive the conduction or turn-off of the internal switch tube of the DC-DC circuit 21.

[0042] In some optional implementation, the DC-DC circuit 21 comprises: a voltage conversion chip circuit, wherein the input ends of the voltage conversion chip circuit are respectively connected with the first input ends of the second surge module 12 and the first input end of the control circuit 22, the output end of the voltage conversion chip circuit is connected with the second input end of the control circuit 22 and the load, and the control end of the voltage conversion chip circuit is connected with the output end of the control circuit 22.

[0043] Optionally, as shown in the figure, the DC-DC circuit 21 comprises: a voltage conversion chip circuit, wherein the input ends of the voltage conversion chip circuit are respectively connected with the first input ends of the second surge module 12 and the first input end of the control circuit 22, the output end of the voltage conversion chip circuit is connected with the second input end of the control circuit 22 and the load, and the control end of the voltage conversion chip circuit is connected with the output end of the control circuit 22. Figure 5 ​​As shown, the voltage conversion chip circuit includes chip U1, resistors R1-R4, capacitors C1-C5, energy storage inductor L1, and the chip U1 internally includes a switch tube. The control circuit 22 controls the on-off of the switch tube to form a charging circuit or a discharging circuit for the energy storage inductor L1, thereby realizing the conversion from direct current to direct current.

[0044] In some optional embodiments, the DC-DC circuit 21 further includes a filter circuit, wherein an input end of the filter circuit is connected with an output end of the voltage conversion chip circuit, and an output end of the filter circuit is connected with the load.

[0045] Optionally, as Figure 5 shown, the filter circuit includes a plurality of parallelly connected capacitors, i.e. Figure 5 capacitors C6-C8, and the filter circuit can filter out the noise of the output voltage of the DC-DC circuit 21 to provide a stable and pure charging voltage for the load. The filter circuit is not limited to Figure 5 the circuit structure.

[0046] In some optional embodiments, the control circuit 22 includes an MCU logic control chip. As Figure 6 shown, the model of the MCU logic control chip can be SC2001, but this is only an example and is not limited thereto. Figure 6 In some optional embodiments, the CC1 end and the CC2 end respectively collect the voltages of the first surge tube and the second surge tube. The CC1 end and the CC2 end can be connected with the first surge tube and the second surge tube through the interface module shown in Figure 7 , and the MCU logic control chip receives the output voltage of the DC-DC circuit through the interface module, and the MCU logic control chip controls the duty cycle of the DC-DC circuit through the interface module. In some optional embodiments, the interface module can be a type-c port. Figure 7

[0047] Specifically, the MCU logic control chip can adjust the amplitude of the output voltage by controlling the duty cycle of the switch tube in the DC-DC circuit 21 based on the control command. After the DC-DC circuit 21 is stabilized, the MCU logic control chip dynamically adjusts the duty cycle of the switch tube by collecting the input voltage and the output voltage of the DC-DC circuit 21 to realize constant voltage output.

[0048] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.​

Claims

1. A surge protection circuit, characterized by, The application relates to a surge protection circuit and a direct-current voltage conversion circuit. The first surge module and the second surge module are connected in parallel, wherein, The first input end of the first surge module inputs a positive voltage, the second input end of the first surge module inputs a negative voltage, and the second input end of the first surge module is grounded. The first input end of the second surge module inputs a positive voltage, the second input end of the second surge module inputs a negative voltage, and the second input end of the second surge module is grounded. The absolute value of the negative clamping voltage of the second surge module is lower than that of the first surge module.

2. The surge protection circuit of claim 1, wherein, The first surge module comprises a first surge tube, wherein, The cathode of the first surge tube inputs a positive voltage, the anode of the first surge tube inputs a negative voltage, and the anode of the first surge tube is also grounded.

3. The surge protection circuit of claim 2, wherein, The second surge module comprises a second surge tube, wherein, The cathode of the second surge tube inputs a positive voltage, the anode of the second surge tube inputs a negative voltage, and the anode of the second surge tube is also grounded. The absolute value of the negative clamping voltage of the second surge tube is lower than that of the first surge tube.

4. A charging circuit, characterized by comprising: The application relates to a surge protection circuit and a direct-current voltage conversion circuit. The input end of the direct-current voltage conversion circuit is connected with the first input end of the second surge module, and the output end of the direct-current voltage conversion circuit is connected with a load. The direct-current voltage conversion circuit comprises a DC-DC circuit and a control circuit, wherein, 5. The charging circuit of claim 4, wherein, The input end of the DC-DC circuit is connected with the first input end of the second surge module, and the output end of the DC-DC circuit is connected with the load. The first input end of the control circuit is connected with the input end of the DC-DC circuit, the second input end of the control circuit is connected with the output end of the DC-DC circuit, the third input end of the control circuit inputs a control command, and the output end of the control circuit is connected with the control end of the DC-DC circuit. The DC-DC circuit comprises a voltage conversion chip circuit, wherein, 6. The charging circuit of claim 5, wherein, The input end of the voltage conversion chip circuit is connected with the first input end of the second surge module and the first input end of the control circuit, the output end of the voltage conversion chip circuit is connected with the second input end of the control circuit and the load, and the control end of the voltage conversion chip circuit is connected with the output end of the control circuit. The DC-DC circuit further comprises a filter circuit, wherein, 7. The charging circuit of claim 6, wherein, The input end of the filter circuit is connected with the output end of the voltage conversion chip circuit, and the output end of the filter circuit is connected with the load. The filter circuit comprises a plurality of capacitors connected in parallel.

8. The charging circuit of claim 7, wherein, The control circuit comprises an MCU logic control chip.

9. The charging circuit of claim 5, wherein, ​

Images