Voltage suppression circuit and power supply system

Abstract

The embodiment of the present application provides a voltage suppression circuit and a power supply system, wherein the voltage suppression circuit includes a first capacitor module, a second capacitor module and a diode; the first end of the first capacitor module is connected to the positive output end of the power module, the positive electrode of the diode and the positive electrode of the load, the negative electrode of the diode is connected to the first end of the second capacitor module, and the second end of the first capacitor module is connected to the second end of the second capacitor module, the negative output end of the power module and the negative electrode of the load. The voltage overshoot at the positive output end of the power module can be suppressed when the load is suddenly disconnected.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a voltage suppression circuit and a power supply system. Background Art

[0002] With the development of semiconductor technology, the switching frequency of switching power supplies is getting higher and higher, and the output capacitance of switching power supplies is also becoming smaller, and more and more ceramic capacitors are used. However, when the output capacitance becomes smaller, if the load is suddenly disconnected, due to the lag of feedback adjustment and protection action, the voltage overshoot at the output end will be very large, which may cause damage to the equipment. How to suppress the voltage overshoot at the output end when the load is suddenly disconnected has become an urgent problem to be solved. Utility Model Content

[0003] The embodiments of the present application provide a voltage suppression circuit and a power supply system, which can suppress voltage overshoot at the positive output terminal of a power module when a load is suddenly disconnected.

[0004] A first aspect of an embodiment of the present application provides a voltage suppression circuit, comprising a first capacitor module, a second capacitor module and a diode; the first end of the first capacitor module is connected to the positive output end of a power module, the positive electrode of the diode and the positive electrode of a load, the negative electrode of the diode is connected to the first end of the second capacitor module, and the second end of the first capacitor module is connected to the second end of the second capacitor module, the negative output end of the power module and the negative electrode of the load.

[0005] In an embodiment of the present application, when the load is disconnected, if the power supply module does not turn off the output in time, the voltage output from the positive output terminal of the power supply module can be absorbed by the second capacitor module through the diode, thereby avoiding overshoot of the voltage at the first end of the first capacitor module and avoiding overshoot of the voltage at the positive output terminal of the power supply module. The voltage overshoot at the positive output terminal of the power supply module can be suppressed when the load is suddenly disconnected.

[0006] Optionally, the voltage suppression circuit further includes a resistance module, a first end of the resistance module is connected to the anode of the diode, and a second end of the resistance module is connected to the cathode of the diode.

[0007] In the embodiment of the present application, a resistor module is added so that the second capacitor module will not be overheated due to high-frequency ripple. The resistance value of the resistor module can be increased so that the second capacitor module will not be overheated due to absorbing high-frequency ripple.

[0008] Optionally, the first capacitor module includes at least one first capacitor.

[0009] Optionally, when the at least one first capacitor includes at least two first capacitors, the at least two first capacitors are connected in parallel or in series.

[0010] In the embodiment of the present application, two first capacitors are connected in parallel so that the first capacitor module can absorb more energy when the load is disconnected.

[0011] Optionally, the at least one first capacitor is a ceramic capacitor.

[0012] In the embodiment of the present application, the first capacitor is a ceramic capacitor, which has good high-frequency performance and can better absorb the high-frequency ripple output by the power module.

[0013] Optionally, the second capacitor module includes at least one second capacitor.

[0014] Optionally, when the at least one second capacitor includes at least two second capacitors, the at least two second capacitors are connected in parallel or in series.

[0015] In the embodiment of the present application, two second capacitors are connected in parallel so that the second capacitor module can absorb more energy when the load is disconnected.

[0016] Optionally, the at least one second capacitor is any one of a ceramic capacitor and an electrolytic capacitor.

[0017] Optionally, the capacity of the second capacitor module is greater than the capacity of the first capacitor module.

[0018] In the embodiment of the present application, the capacity of the second capacitor module is set to be equal to the capacity of the first capacitor module, so that when the load is suddenly disconnected, the second capacitor module can absorb more energy, thereby avoiding overshoot of the voltage at the first end of the first capacitor module.

[0019] Optionally, the voltage suppression circuit further includes an inductor module, and the inductor module is connected in series or in parallel with the first capacitor module.

[0020] Optionally, the positive output terminal of the power module and the positive electrode of the load are connected via a switch.

[0021] Optionally, the power supply module is a switching power supply, and the load is a high-frequency load.

[0022] A second aspect of an embodiment of the present application provides a power supply system, comprising a voltage suppression circuit, a power supply module and a load as described in any one of the first aspect of the embodiment of the present application, wherein the power supply module supplies power to the load through the voltage suppression circuit.

[0023] The voltage suppression circuit of the embodiment of the present application includes a first capacitor module, a second capacitor module and a diode; the first end of the first capacitor module is connected to the positive output end of the power module, the positive electrode of the diode and the positive electrode of the load, the negative electrode of the diode is connected to the first end of the second capacitor module, and the second end of the first capacitor module is connected to the second end of the second capacitor module, the negative output end of the power module and the negative electrode of the load. In the embodiment of the present application, when the load is disconnected, if the power module does not turn off the output in time, the voltage output from the positive output end of the power module can be absorbed by the second capacitor module through the diode, avoiding the voltage of the first end of the first capacitor module from overshooting, avoiding the voltage of the positive output end of the power module from overshooting, and suppressing the voltage overshoot of the positive output end of the power module when the load is suddenly disconnected. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 is a schematic diagram of the structure of a voltage suppression circuit provided in an embodiment of the present application;

[0026] Figure 2 is a schematic diagram of the structure of another voltage suppression circuit provided in an embodiment of the present application;

[0027] Figure 3 is a schematic diagram of the structure of another voltage suppression circuit provided in an embodiment of the present application;

[0028] Figure 4 is a schematic diagram of the structure of another voltage suppression circuit provided in an embodiment of the present application;

[0029] Figure 5 is a schematic diagram of the structure of another voltage suppression circuit provided in an embodiment of the present application;

[0030] Figure 6 is a schematic diagram of the structure of another voltage suppression circuit provided in an embodiment of the present application;

[0031] Figure 7 It is a structural schematic diagram of a pre-charging system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0033] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, products or devices.

[0034] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0035] See also Figure 1 , Figure 1 Schematic diagram of a voltage suppression circuit provided by an embodiment of the present application. Figure 1 As shown, the voltage suppression circuit 100 includes a first capacitor module 10, a second capacitor module 20 and a diode D1; the first end of the first capacitor module 10 is connected to the positive output end of the power module 200, the positive electrode of the diode D1 and the positive electrode of the load 300, the negative electrode of the diode D1 is connected to the first end of the second capacitor module 20, and the second end of the first capacitor module 10 is connected to the second end of the second capacitor module 20, the negative output end of the power module and the negative electrode of the load 300.

[0036] The first capacitor module 10 may include at least one capacitor. When the power module supplies power to the load 300, the first capacitor module 10 may absorb the high-frequency ripple output by the power module. The first capacitor module 10 may use a capacitor with good high-frequency performance, such as a ceramic capacitor.

[0037] Optionally, the first capacitor module 10 includes at least one first capacitor.

[0038] Figure 2 For example, the first capacitor module 10 includes a first capacitor C1. Figure 2 , Figure 2 It is a schematic diagram of the structure of another voltage suppression circuit provided in an embodiment of the present application. Figure 2 is Figure 1 Based on Figure 2 As shown, the first capacitor module 10 includes a first capacitor C1. A first end of the first capacitor C1 is connected to the positive output end of the power module, and a second end of the first capacitor C1 is connected to the negative output end of the power module.

[0039] Wherein, when the first capacitor module 10 includes at least two first capacitors C1, the at least two first capacitors C1 are connected in parallel or in series.

[0040] Figure 3 Take the example that the first capacitor module 10 includes two first capacitors C1 , and the two first capacitors C1 are connected in parallel.

[0041] See also Figure 3 , Figure 3 It is a schematic diagram of the structure of another voltage suppression circuit provided in an embodiment of the present application. Figure 3 is Figure 1 Based on Figure 3 As shown, the first capacitor module 10 includes two first capacitors C1: capacitor C11 and capacitor C12. Capacitor C11 and capacitor C12 are connected in parallel. The first end of capacitor C11 is connected to the first end of capacitor C12 and the positive output end of the power module, and the second end of capacitor C11 is connected to the second end of capacitor C12 and the negative output end of the power module.

[0042] In the embodiment of the present application, two first capacitors C1 are connected in parallel, so that the first capacitor module 10 can absorb more energy when the load 300 is disconnected.

[0043] The load 300 is disconnected, which means that the load 300 loses the power supply of the power module. There are two types of disconnection of the load 300: the power module actively disconnects and the load 300 is passively disconnected. In the case where the power module is actively disconnected, the power module will turn off the output of the power module before disconnecting the power supply of the load 300, and at this time, the first end of the first capacitor module 10 will not have a voltage overshoot. In the case of passive disconnection of the load 300, when the load 300 is disconnected, the power module cannot turn off the output in time, and the power module still has an output. Without adding the voltage suppression circuit of the embodiment of the present application, it will cause a voltage overshoot at the first end of the first capacitor module 10; in the case of adding the voltage suppression circuit of the embodiment of the present application, the voltage of the first end of the first capacitor module 10 is avoided from overshooting, and the voltage of the positive output end of the power module is avoided from overshooting, and the voltage overshoot of the positive output end of the power module can be suppressed when the load 300 is suddenly disconnected.

[0044] The power module actively disconnects, that is, when it is detected that the load 300 does not need to continue to be supplied with power, the output of the power module is turned off, thereby disconnecting the power supply to the load 300.

[0045] The load 300 is disconnected passively, which may be that the load 300 is cut off manually, or the load 300 is disconnected after a fault is detected inside the load 300.

[0046] Optionally, the at least one first capacitor is a ceramic capacitor.

[0047] The first capacitor C1 is a ceramic capacitor, which has good high-frequency performance and can better absorb the high-frequency ripple output by the power module.

[0048] Generally speaking, ceramic capacitors have better high-frequency performance and relatively small capacity. Electrolytic capacitors have relatively large capacity and relatively poor high-frequency performance. If the high-frequency ripple output by the power module is large or the high-frequency ripple generated by the load 300 is large, if the first electrolytic module uses an electrolytic capacitor, the electrolytic capacitor will heat up and easily cause damage to the electrolytic capacitor. The first capacitor C1 of the embodiment of the present application uses a ceramic capacitor, which has better high-frequency performance. Compared with the use of an electrolytic capacitor, it can better absorb the high-frequency ripple output by the power module and is less likely to be damaged.

[0049] Optionally, the second capacitor module 20 includes at least one second capacitor.

[0050] Figure 2 Take the second capacitor module 20 including a second capacitor C2 as an example. Figure 2 As shown, the second capacitor module 20 includes a second capacitor C2. A first end of the second capacitor C2 is connected to the cathode of the diode D1, and a second end of the second capacitor C2 is connected to the negative output end of the power module.

[0051] Wherein, when the second capacitor module 20 includes at least two second capacitors C2, the at least two second capacitors C2 are connected in parallel or in series.

[0052] Figure 3 For example, the second capacitor module 20 includes two second capacitors C2 , and the two second capacitors C2 are connected in parallel.

[0053] like Figure 3 As shown, the second capacitor module 20 includes two second capacitors C2: capacitor C21 and capacitor C22. Capacitor C21 and capacitor C22 are connected in parallel. The first end of capacitor C21 is connected to the first end of capacitor C22 and the cathode of diode D1, and the second end of capacitor C21 is connected to the second end of capacitor C22 and the negative output end of the power module.

[0054] In the embodiment of the present application, two second capacitors C2 are connected in parallel, so that the second capacitor module 20 can absorb more energy when the load 300 is disconnected.

[0055] Optionally, the at least one second capacitor is any one of a ceramic capacitor and an electrolytic capacitor.

[0056] In the embodiment of the present application, the second capacitor C2 can be set as a ceramic capacitor or an electrolytic capacitor. The function of the second capacitor C2 is to absorb the energy that the first capacitor module 10 cannot absorb when the load 300 is suddenly disconnected, thereby avoiding the voltage overshoot at the first end of the first capacitor module 10, so that the first capacitor C1 in the first capacitor module 10 passes the test.

[0057] Voltage overshoot refers to the voltage exceeding the set amplitude range. For example, the normal voltage range of the first end of the first capacitor C1 is V1. If the voltage of the first end of the first capacitor C1 exceeds V1*110% or V1*120%, it is considered that the first capacitor C1 has a capacitance overshoot and the first capacitor C1 cannot pass the test.

[0058] Optionally, the capacity of the second capacitor module 20 is greater than the capacity of the first capacitor module 10 .

[0059] In the embodiment of the present application, the capacity of the second capacitor module 20 is set to be greater than the capacity of the first capacitor module 10, so that when the load 300 is suddenly disconnected, the second capacitor module 20 can absorb more energy, thereby avoiding overshoot of the voltage at the first end of the first capacitor module 10.

[0060] The diode D1 has a fast response speed. When the load 300 is suddenly disconnected, when the voltage at the positive output terminal of the power module increases, the diode D1 is turned on, so that the second capacitor module 20 absorbs the energy output by the positive output terminal of the power module, thereby avoiding overshoot of the voltage at the first end of the first capacitor module 10 and avoiding overshoot of the voltage at the positive output terminal of the power module. The voltage overshoot at the positive output terminal of the power module can be suppressed when the load 300 is suddenly disconnected.

[0061] When the load 300 is suddenly disconnected, the power module fails to turn off the output in time due to the lag in feedback adjustment and protection action, resulting in an overshoot of the voltage at the output end of the power module.

[0062] In an embodiment of the present application, when the load 300 is disconnected, if the power module does not turn off the output in time, the voltage output from the positive output terminal of the power module can be absorbed by the second capacitor module 20 through the diode D1, thereby avoiding overshoot of the voltage at the first end of the first capacitor module 10 and avoiding overshoot of the voltage at the positive output terminal of the power module. The voltage overshoot at the positive output terminal of the power module can be suppressed when the load 300 is suddenly disconnected.

[0063] Optionally, the voltage suppression circuit further includes a resistance module, a first end of the resistance module is connected to the anode of the diode D1 , and a second end of the resistance module is connected to the cathode of the diode D1 .

[0064] The resistor module may include at least one resistor.

[0065] When the at least one resistor includes at least two resistors, the at least two resistors are connected in parallel or in series.

[0066] Figure 4 Take the resistor module including one resistor as an example.

[0067] See also Figure 4 , Figure 4 It is a schematic diagram of the structure of another voltage suppression circuit provided in an embodiment of the present application. Figure 4 is Figure 2 Based on Figure 4 As shown, the voltage suppression circuit further includes a first resistor R1, a first end of the first resistor R1 is connected to the anode of the diode D1, and a second end of the first resistor R1 is connected to the cathode of the diode D1.

[0068] In the embodiment of the present application, the first resistor R1 is added to prevent the second capacitor module 20 from overheating due to high-frequency ripple. For example, the resistance value of the first resistor R1 can be set to increase the resistance value of the first resistor R1 so that the second capacitor module 20 will not overheat due to absorbing high-frequency ripple.

[0069] Optionally, the voltage suppression circuit further includes an inductor module, and the inductor module is connected in series or in parallel with the first capacitor module 10 .

[0070] The inductor module may include at least one inductor. When the at least one inductor includes at least two inductors, the at least two inductors are connected in parallel or in series.

[0071] See also Figure 5 , Figure 5 It is a schematic diagram of the structure of another voltage suppression circuit provided in an embodiment of the present application. Figure 5 is Figure 4 Based on Figure 5 As shown, the inductor module takes a first inductor L1 as an example, wherein the first inductor L1 is connected in series with the first capacitor C1.

[0072] When the load 300 is disconnected, if the power module does not turn off the output in time, since the current of the first inductor L1 cannot change suddenly, a higher electromotive force will appear in the first inductor L1, which will generate a voltage, causing the voltage at the first end of the first capacitor C1 to overshoot. By providing the second capacitor module 20 and the diode D1, the voltage output from the positive output end of the power module can be absorbed by the second capacitor module 20 through the diode D1, avoiding the voltage at the first end of the first capacitor C1 from overshooting, avoiding the voltage at the positive output end of the power module from overshooting, and suppressing the voltage overshoot at the positive output end of the power module when the load 300 is suddenly disconnected.

[0073] The first inductor L1 may be a parasitic inductor of the first capacitor C1.

[0074] Optionally, the power supply module is a switching power supply, and the load 300 is a high-frequency load 300 .

[0075] The high frequency load 300 may be a load that allows high frequency signals to pass through. A switching power supply is a high frequency power conversion device that controls the switching power supply to output a stable voltage by adjusting the on and off time of a switch (eg, a transistor) inside the switching power supply.

[0076] The embodiment of the present application can be applied to the scene of the switching power supply and the high-frequency load 300. Since the switching power supply can generate high-frequency ripples, the high-frequency load 300 can also generate high-frequency ripples. Through the voltage suppression circuit of the embodiment of the present application, the high-frequency ripples can be effectively filtered out. When the load 300 is disconnected, if the power module does not turn off the output in time, the voltage outputted by the positive output terminal of the power module can be absorbed by the second capacitor module 20 through the diode D1, so as to avoid the voltage of the first terminal of the first capacitor module 10 from overshooting, and avoid the voltage of the positive output terminal of the power module from overshooting. The voltage overshoot of the positive output terminal of the power module can be suppressed when the load 300 is suddenly disconnected.

[0077] See also Figure 6 , Figure 6 It is a schematic diagram of the structure of another voltage suppression circuit provided in an embodiment of the present application. Figure 6 is Figure 4 Based on Figure 6 As shown, the positive output terminal of the power module and the positive electrode of the load 300 are connected via a switch S1. When the switch S1 is closed, the power module supplies power to the load 300 via the voltage suppression circuit. When the switch S1 is disconnected, the load 300 is disconnected from the power supply. The disconnection of the switch S1 may be an active disconnection of the power module.

[0078] See also Figure 7 , Figure 7is a schematic diagram of a power supply system provided in an embodiment of the present application, such as Figure 7 As shown, the power supply system 1000 may include a voltage suppression circuit, a power module and a load 300 , and the power module supplies power to the load 300 through the voltage suppression circuit.

[0079] The specific structure of the voltage suppression circuit can be found in the above Figures 1 to 6 Any voltage suppression circuit.

[0080] In the power supply system of the embodiment of the present application, when the load 300 is disconnected, if the power module does not turn off the output in time, the voltage output from the positive output terminal of the power module can be absorbed by the second capacitor module 20 through the diode D1, so as to avoid overshoot of the voltage at the first end of the first capacitor module 10 and the voltage at the positive output terminal of the power module. The voltage overshoot at the positive output terminal of the power module can be suppressed when the load 300 is suddenly disconnected.

[0081] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0082] In the several embodiments provided in the present application, it should be understood that the disclosed voltage suppression circuit can be implemented in other ways. For example, the voltage suppression circuit embodiments described above are only schematic, and for example, the division of the units is only a logical function division, and there may be other division methods 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.

Claims

1. A voltage suppression circuit, characterized in that: It includes a first capacitor module, a second capacitor module and a diode; the first end of the first capacitor module is connected to the positive output end of the power module, the positive electrode of the diode and the positive electrode of the load, the negative electrode of the diode is connected to the first end of the second capacitor module, and the second end of the first capacitor module is connected to the second end of the second capacitor module, the negative output end of the power module and the negative electrode of the load.

2. The voltage suppression circuit according to claim 1, characterized in that: The voltage suppression circuit further includes a resistance module, a first end of the resistance module is connected to the anode of the diode, and a second end of the resistance module is connected to the cathode of the diode.

3. The voltage suppression circuit according to claim 1, characterized in that: The first capacitor module includes at least one first capacitor.

4. The voltage suppression circuit according to claim 3, characterized in that: The at least one first capacitor is a ceramic capacitor.

5. The voltage suppression circuit according to claim 1, characterized in that: The second capacitor module includes at least one second capacitor.

6. The voltage suppression circuit according to claim 5, characterized in that: The at least one second capacitor is any one of a ceramic capacitor and an electrolytic capacitor.

7. The voltage suppression circuit according to claim 1, characterized in that: The capacity of the second capacitor module is greater than that of the first capacitor module.

8. The voltage suppression circuit according to any one of claims 1 to 7, characterized in that: The voltage suppression circuit further includes an inductor module, which is connected in series or in parallel with the first capacitor module.

9. The voltage suppression circuit according to any one of claims 1 to 7, characterized in that: The positive output terminal of the power module and the positive electrode of the load are connected via a switch.

10. A power supply system, characterized in that: The invention comprises the voltage suppression circuit according to any one of claims 1 to 9, a power supply module and a load, wherein the power supply module supplies power to the load through the voltage suppression circuit.

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