Spiking absorption line

Abstract

The application relates to a sharp peak absorption circuit. The sharp peak absorption circuit comprises a MOS tube Q1, a first absorption module, a second absorption module and a transformer, the first absorption module is electrically connected with the MOS tube Q1; the second absorption module comprises a resistor R3, a diode TVS1 and a diode D3, a first end of the resistor R3 is electrically connected with the first absorption module, a second end of the resistor R3 is electrically connected with a first end of the diode TVS1, a second end of the diode TVS1 is electrically connected with a first end of the diode D3; and the transformer is electrically connected with a second end of the diode D3. The scheme provided by the application can absorb sharp peak voltage and prevent the sharp peak voltage from damaging the MOS tube.

Description

Technical Field

[0001] This utility model relates to the field of transformer technology, and in particular to a spike absorption circuit. Background Technology

[0002] In related technologies, switching power supplies typically use high-frequency transformers for voltage conversion. Due to the transformer coupling performance and the change in secondary load, the MOSFET will generate a high voltage spike at startup. If the voltage spike is too high, it will damage the MOSFET. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a spike absorption circuit that can absorb spike voltage and prevent spike voltage from damaging the MOSFET.

[0004] The objective of this utility model is achieved through the following technical solution: This application provides a spike absorption circuit, comprising: a MOSFET Q1; a first absorption module electrically connected to the MOSFET Q1; a second absorption module including a resistor R3, a diode TVS1, and a diode D3, wherein a first terminal of the resistor R3 is electrically connected to the first absorption module, a second terminal of the resistor R3 is electrically connected to a first terminal of the diode TVS1, and a second terminal of the diode TVS1 is electrically connected to a first terminal of the diode D3; and a transformer electrically connected to the second terminal of the diode D3.

[0005] The first absorption module includes a diode D1, a resistor R1, and a capacitor C3. The first end of the diode D1 is electrically connected to the MOS transistor Q1. The second end of the diode D1 is electrically connected to the first end of the capacitor C3 and the first end of the resistor R1. The second end of the resistor R1 is electrically connected to the second end of the capacitor C3 and the first end of the resistor R3.

[0006] It also includes a capacitor C1, the first end of which is electrically connected to the second end of the capacitor C3, and the second end of the capacitor C1 is grounded.

[0007] It also includes a power supply module, which includes a diode D2 and a capacitor C2. The first end of the diode D2 is electrically connected to the transformer, the second end of the diode D2 is electrically connected to the first end of the capacitor C2, and the second end of the capacitor C2 is grounded.

[0008] It also includes an output module, which includes a diode DS1 and a capacitor CS1. The first end of the diode DS1 is electrically connected to the transformer, and the second end of the diode DS1 is electrically connected to the capacitor CS1.

[0009] The output module further includes a capacitor CS2 and a resistor RS1. The first end of the capacitor CS2 is electrically connected to the first end of the diode DS1, the second end of the capacitor CS2 is electrically connected to the first end of the resistor RS1, and the second end of the resistor RS1 is electrically connected to the second end of the diode DS1. Compared with the prior art, the present invention has at least the following advantages: When the startup voltage spike is too high, diode D3 rectifies the AC power from the transformer into DC power, diode TVS1 acts as a voltage regulator, and resistor R3 acts as a current limiter. Through the cooperation of these three components, the voltage is finally delivered to the VBUS port, thereby absorbing the voltage spike and preventing the voltage spike from damaging the MOSFET Q1. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly described below.

[0011] Figure 1 This is a functional block diagram of the spike absorption circuit in one embodiment of the present invention; Figure 2 This is a circuit diagram of a spike absorption circuit in one embodiment of the present invention; Figure 3 This is a schematic diagram of the transformer structure in one embodiment of the present invention. Detailed Implementation

[0012] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0013] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0014] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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 refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0015] Switching power supplies typically use high-frequency transformers for voltage conversion. Due to the transformer's coupling performance and the change in secondary load, the MOSFET will generate a high voltage spike at startup. If the spike voltage is too high, it will damage the MOSFET.

[0016] To address the aforementioned issues, this application provides a spike absorption circuit capable of absorbing voltage spikes and preventing them from damaging the MOSFET.

[0017] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0018] See Figure 1 and Figure 2 A spike absorption circuit includes: a MOSFET Q1, a first absorption module 100, a second absorption module 200, and a transformer 300. The first absorption module 100 is electrically connected to the MOSFET Q1. The second absorption module 200 includes a resistor R3, a diode TVS1, and a diode D3. The first end of the resistor R3 is electrically connected to the first absorption module 100, the second end of the resistor R3 is electrically connected to the first end of the diode TVS1, and the second end of the diode TVS1 is electrically connected to the first end of the diode D3. The transformer 300 is electrically connected to the second end of the diode D3.

[0019] It should be noted that when the startup voltage spike is too high, diode D3 rectifies the AC power from transformer 300 into DC power, diode TVS1 acts as a voltage regulator, and resistor R3 acts as a current limiter. Through the cooperation of these three components, the voltage is finally delivered to the VBUS port, thereby absorbing the voltage spike and preventing the voltage spike from damaging the MOSFET Q1.

[0020] See Figure 3Furthermore, in one embodiment, the transformer 300 includes: a first winding and a second winding. The first winding includes a first pin 1, a first primary winding N1, a second pin 2, a second primary winding N3, a third pin 3, a detection winding N5, and a fourth pin 4. The first end of the first primary winding N1 is wound on the first pin 1, the second end of the first primary winding N1 is wound on the second pin 2, the first end of the second primary winding N3 is wound on the second pin 2, the second end of the second primary winding N3 is wound on the third pin 3, and the first end of the detection winding N5 is wound on the fourth pin 4. The second winding includes a fifth pin 6, a third primary winding N4, and a sixth pin 7. The first end of the third primary winding N4 is wound on the fifth pin 6, the second end of the third primary winding N4 is wound on the sixth pin 7, and the second end of the detection winding N5 is wound on the sixth pin 7.

[0021] See Figure 3 Specifically, the transformer 300 also includes a third winding, which includes a secondary winding N2, a seventh pin 8, and an eighth pin 9. The first end of the secondary winding N2 is wound on the seventh pin 8, and the second end of the secondary winding N2 is wound on the eighth pin 9.

[0022] It should be noted that the first primary winding N1 and the second primary winding N3 form the main winding, and the third primary winding N4 is the VCC power supply winding. The first primary winding N1 and the second primary winding N2 use multi-strand enameled wire, while the third primary winding N4 uses single-strand enameled wire. Furthermore, the first primary winding N1 starts at pin 1, and the detection winding N5 starts at pin 4. The detection winding N5 follows the winding of the first primary winding N1. After the first primary winding N1 is wound, it is connected to pin 2, while the detection winding N5 remains unconnected. Then, the secondary winding N2 is wound, followed by windings of the detection winding N5 and the second primary winding N3. After winding, the second primary winding N3 is connected to pin 3, the detection winding N5 is connected to pin 7, and the third primary winding N4 starts at pin 7 and ends at pin 6. By using the above winding method, the detection winding N5 is consistent with the main winding composed of the first primary winding N1 and the second primary winding N3, and the induced peak voltage is consistent, thereby realizing real-time monitoring of the peak voltage, so that the second absorption module 200 rectifies the peak voltage and connects it to the VBUS port.

[0023] Preferably, the winding direction of the detection winding N5 is the same as that of the main winding.

[0024] It is understandable that having the same winding direction reduces leakage inductance between the detection winding N5 and the main winding. Leakage inductance is uncoupled magnetic field energy, which leads to signal attenuation. This, in turn, allows the detection winding N5 to sense changes in the magnetic field of the main winding more efficiently, especially voltage spikes. Secondly, since the detection winding N5 and the main winding have the same winding direction and are usually tightly coupled, both will sense external common-mode interference to an equal degree. Preferably, the ratio of the number of turns of the detection winding N5 to the number of turns of the first primary winding N1 is 1:1.

[0025] Preferably, the ratio of the number of turns of the detection winding N5 to the number of turns of the second primary winding N3 is 1:1.

[0026] It should be noted that for voltage spikes in the main winding of a switching power supply, a detection winding N5 with the same number of turns can more accurately reproduce the amplitude and waveform of the signal. If the detection winding N5 has fewer turns, the amplitude of the induced transient signal will be proportionally reduced, which may cause small-amplitude spikes to be drowned out by noise and unable to be effectively identified. If the detection winding N5 has more turns, the signal will be amplified, but this may exceed the range of the detection circuit, leading to signal distortion or circuit damage. Therefore, having the same number of turns ensures that the transient signal is transmitted to the detection end "in its original form," which is especially suitable for scenarios that require capturing the extreme values ​​of the main winding voltage, providing accurate data for overvoltage protection and fault diagnosis.

[0027] See Figure 2 Furthermore, in one embodiment, the first absorption module 100 includes a diode D1, a resistor R1, and a capacitor C3. The first end of the diode D1 is electrically connected to the MOSFET Q1, the second end of the diode D1 is electrically connected to the first end of the capacitor C3 and the first end of the resistor R1, and the second end of the resistor R1 is electrically connected to the second end of the capacitor C3 and the first end of the resistor R3.

[0028] It should be noted that when the peak voltage at the drain of MOSFET Q1 is too high, the voltage is rectified by diode D1 and charges capacitor C3. After MOSFET Q1 reaches a steady state, the voltage of capacitor C3 is released through resistor R1, and so on, absorbing the peak voltage.

[0029] See Figure 2 Furthermore, in one embodiment, a spike absorption circuit further includes a capacitor C1, the first end of which is electrically connected to the second end of a capacitor C3, and the second end of the capacitor C1 is grounded.

[0030] It should be noted that capacitor C1 serves as a filter.

[0031] See Figure 2Furthermore, in one embodiment, a spike absorption circuit further includes a power supply module, which includes a diode D2 and a capacitor C2. The first end of the diode D2 is electrically connected to the transformer 300, the second end of the diode D2 is electrically connected to the first end of the capacitor C2, and the second end of the capacitor C2 is grounded.

[0032] It should be noted that the first terminal of diode D2 is electrically connected to the third primary winding N4 of transformer 300. Diode D2 is used for circuit protection, while capacitor C2 is used for filtering.

[0033] See Figure 2 Furthermore, in one embodiment, a spike absorption circuit further includes an output module, which includes a diode DS1 and a capacitor CS1. The first terminal of the diode DS1 is electrically connected to the transformer 300, and the second terminal of the diode DS1 is electrically connected to the capacitor CS1. Specifically, the output module further includes a capacitor CS2 and a resistor RS1. The first terminal of the capacitor CS2 is electrically connected to the first terminal of the diode DS1, the second terminal of the capacitor CS2 is electrically connected to the first terminal of the resistor RS1, and the second terminal of the resistor RS1 is electrically connected to the second terminal of the diode DS1.

[0034] It should be noted that the first terminal of diode DS1 is electrically connected to the secondary winding N2 of transformer 300. The voltage output from transformer 300 is rectified by diode DS1 and filtered by capacitor CS1 before being output through the VOUT port. Furthermore, capacitor CS2 and resistor RS1 are connected in parallel across diode DS1 to form a spike absorption circuit.

[0035] The solution of this application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of each embodiment have different focuses; for parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. Those skilled in the art should also understand that the actions and modules involved in the specification are not necessarily essential to this application. Furthermore, it is understood that the steps in the method of this application embodiment can be adjusted, combined, and deleted according to actual needs, and the modules in the device of this application embodiment can be combined, divided, and deleted according to actual needs. The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A peak absorption circuit, characterized in that, include: MOSFET Q1; The first absorption module is electrically connected to the MOS transistor Q1; The second absorption module includes a resistor R3, a diode TVS1, and a diode D3. The first end of the resistor R3 is electrically connected to the first absorption module, the second end of the resistor R3 is electrically connected to the first end of the diode TVS1, and the second end of the diode TVS1 is electrically connected to the first end of the diode D3. The transformer is electrically connected to the second terminal of the diode D3.

2. The spike absorption circuit according to claim 1, characterized in that, The first absorption module includes a diode D1, a resistor R1, and a capacitor C3. The first end of the diode D1 is electrically connected to the MOS transistor Q1. The second end of the diode D1 is electrically connected to the first end of the capacitor C3 and the first end of the resistor R1. The second end of the resistor R1 is electrically connected to the second end of the capacitor C3 and the first end of the resistor R3.

3. The spike absorption circuit according to claim 2, characterized in that, It also includes a capacitor C1, the first end of which is electrically connected to the second end of the capacitor C3, and the second end of the capacitor C1 is grounded.

4. The spike absorption circuit according to claim 1, characterized in that, It also includes a power supply module, which includes a diode D2 and a capacitor C2. The first end of the diode D2 is electrically connected to the transformer, the second end of the diode D2 is electrically connected to the first end of the capacitor C2, and the second end of the capacitor C2 is grounded.

5. The spike absorption circuit according to claim 1, characterized in that, It also includes an output module, which includes a diode DS1 and a capacitor CS1. The first end of the diode DS1 is electrically connected to the transformer, and the second end of the diode DS1 is electrically connected to the capacitor CS1.

6. The spike absorption circuit according to claim 5, characterized in that, The output module further includes a capacitor CS2 and a resistor RS1. The first end of the capacitor CS2 is electrically connected to the first end of the diode DS1, the second end of the capacitor CS2 is electrically connected to the first end of the resistor RS1, and the second end of the resistor RS1 is electrically connected to the second end of the diode DS1.

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