Cathode N-MOS rapid turn-off circuit and DC power supply

Abstract

The invention relates to the technical field of battery charging protection, and discloses a cathode N-MOS rapid turn-off circuit and a DC power supply. The cathode N-MOS rapid turn-off circuit comprises an overvoltage and undervoltage protection unit and a rapid turn-off unit. The quick turn-off unit comprises a switch tube QT3, a switch tube QT4 and a switch tube QT6; when the input voltage of the overvoltage and undervoltage protection unit exceeds the overvoltage threshold value or is smaller than the undervoltage threshold value, the switching tube QT6, the switching tube QT3 and the switching tube QT4 are all switched off or not switched on, and then the main N-MOS switching assembly is controlled to be switched off or not switched on. According to the invention, when the input voltage of the power transmission line is abnormal (overvoltage / undervoltage), the main N-MOS switch assembly can be rapidly turned off, the control logic is simple and reliable, turn-off delay basically does not exist, and the impact of transient large current on a device can be effectively inhibited.

Description

Technical Field

[0001] The present invention relates to the technical field of battery charging protection, and in particular to a negative electrode N-MOS fast shutdown circuit and a DC power supply. Background Art

[0002] As electronic devices rapidly develop toward higher integration, lower power consumption, and higher reliability, circuit protection technology is becoming increasingly important. Reverse polarity protection and rapid shutdown are key features for ensuring safe device operation. Reverse polarity protection prevents device damage caused by incorrect power polarity, while rapid shutdown rapidly cuts off current under abnormal operating conditions such as overcurrent or short circuits, preventing energy accumulation and malfunctions. However, existing technologies still face numerous technical bottlenecks in these two areas, necessitating innovative designs to optimize performance.

[0003] Traditional reverse polarity protection solutions rely on diodes or mechanical relays, but these solutions have significant drawbacks. For example, while diode-based reverse polarity protection circuits are simple, the diode's forward voltage drop (approximately 0.7V) results in significant power loss, significantly reducing system efficiency under high voltage or high current conditions. Low-resistance switching solutions reduce on-resistance, but are highly dependent on threshold voltage, making them less reliable under dynamic loads or voltage fluctuations.

[0004] In the field of fast shutdown, current technologies generally face a contradiction between response speed and structural complexity. MOS transistor drive circuits achieve rapid gate discharge through switching circuits and resistors, but require additional components such as inverters and capacitors, resulting in a complex circuit topology. This is also susceptible to parasitic parameters in high-frequency switching scenarios, reducing stability. Lithium battery protection systems trigger shutdown by detecting current changes, but rely on multi-level logic control such as overcharge / over-discharge detection and delay circuits. The response time can be delayed by tens of microseconds, making it unable to cope with instantaneous high current shocks and potentially damaging the switch due to energy accumulation. Furthermore, while some solutions improve switching speed, they lack integrated reverse polarity protection, requiring the addition of additional protection modules, leading to system redundancy and increased costs.

[0005] In summary, the problems of the existing technology include:

[0006] 1. Conflict between efficiency and loss: Traditional reverse polarity protection circuits are inefficient due to diode voltage drop or complex control logic, making them difficult to meet the requirements of high-efficiency equipment.

[0007] 2. Insufficient response speed: Existing fast shutdown circuits rely on multi-level detection and logic processing, resulting in shutdown delays and inability to effectively suppress the impact of transient high currents on devices;

[0008] 3. Structural complexity and cost: To achieve dual functions (anti-reverse polarity + fast shutdown), existing solutions require stacking independent modules, which not only increases circuit area but also increases manufacturing cost.

[0009] 4. Poor dynamic adaptability: Some solutions have weak adaptability to voltage fluctuations or load changes. For example, threshold voltage-dependent designs are not stable enough over a wide input voltage range.

[0010] The above information is presented as background information only to assist with an understanding of the present disclosure and is not a determination or admission that any of the above may be applicable as prior art with respect to the present disclosure. Summary of the Invention

[0011] The object of the present invention is to provide a negative electrode N-MOS fast shutdown circuit and a DC power supply to solve or at least partially solve the technical problems existing in the prior art.

[0012] To achieve this object, the present invention adopts the following technical solutions:

[0013] In a first aspect, the present invention provides a negative electrode N-MOS fast shutdown circuit, comprising an over-voltage and under-voltage protection unit and a fast shutdown unit;

[0014] The fast shutdown unit includes a switch tube QT3, a switch tube QT4 and a switch tube QT6;

[0015] The control terminal of the switch tube QT6 is electrically connected to the drive signal output terminal of the over-voltage and under-voltage protection unit, the positive terminal of the switch tube QT6 is electrically connected to the positive terminal of the charger, the negative terminal of the switch tube QT6 is electrically connected to the first end of the resistor RT15 and the first end of the resistor RT66, the second end of the resistor RT66 is electrically connected to the anode of the diode DT1, and the cathode of the diode DT1 is electrically connected to the first end of the capacitor CT12, the first end of the resistor RT61, and the first end of the resistor RT63, respectively;

[0016] The second end of resistor RT15 is electrically connected to the control terminal of switch QT3. The positive terminal of switch QT3 is electrically connected to the first end of resistor RT59. The second end of resistor RT59 is electrically connected to the control terminal of switch QT4 and the second end of resistor RT61, respectively. The negative terminal of switch QT3 and the second end of capacitor CT12 are both electrically connected to the negative terminal of switch QT4. The second end of resistor RT63 is electrically connected to the first end of resistor RT64, and the second end of resistor RT64 is electrically connected to the positive terminal of switch QT4. The second end of resistor RT64 is also electrically connected to the control terminal of the negative main N-MOS switch component.

[0017] When the input voltage of the over-voltage / under-voltage protection unit is between a preset over-voltage threshold and a preset under-voltage threshold, the drive signal output terminal outputs a first drive signal to control the switch tubes QT6, QT3, and QT4 to be turned on, thereby controlling the main N-MOS switch component to be turned on;

[0018] When the input voltage of the over-voltage / under-voltage protection unit exceeds the overvoltage threshold or is less than the undervoltage threshold, the drive signal output end does not output the first drive signal, and the switch tubes QT6, QT3, and QT4 are all turned off or non-conducting, thereby controlling the main N-MOS switch component to be turned off or non-conducting.

[0019] Optionally, a resistor RT60 is further electrically connected between the control terminal of the switch tube QT3 and the negative terminal of the switch tube QT3, a resistor RT62 is further electrically connected between the control terminal of the switch tube QT4 and the negative terminal of the switch tube QT4, and a resistor RT14 is further electrically connected between the control terminal of the switch tube QT6 and the positive terminal of the switch tube QT6.

[0020] Optionally, the over-voltage and under-voltage protection unit includes a switch tube QT2, a switch tube QT5, a Zener diode ZT1 and a Zener diode ZT3;

[0021] The cathode of the Zener diode ZT1 is electrically connected to the cathode of the Zener diode ZT3 and the positive terminal of the switch QT6, respectively. The anode of the Zener diode ZT1 is electrically connected to the first end of the resistor RT10. The second end of the resistor RT10 is electrically connected to the first end of the resistor RT11 and the control terminal of the switch QT2, respectively. The negative terminal of the switch QT2 and the second end of the resistor RT11 are both electrically connected to the negative terminal of the charger.

[0022] The anode of the Zener diode ZT3 is electrically connected to the first end of the resistor RT6. The second end of the resistor RT6 is electrically connected to the first end of the resistor R65, the first end of the capacitor CT0, the first end of the resistor RT12, and the control end of the switch QT5. The positive terminal of the switch QT2 is electrically connected to the second end of the resistor R65. The negative terminal of the switch QT5, the second end of the capacitor CT0, and the second end of the resistor RT12 are all electrically connected to the negative terminal of the charger.

[0023] The positive terminal of the switch tube QT5 is electrically connected to the control terminal of the switch tube QT6 through the resistor RT13.

[0024] Optionally, the switch tube QT2 , the switch tube QT3 , the switch tube QT4 and the switch tube QT5 are all NPN transistors, and the switch tube QT6 is a PNP transistor.

[0025] Optionally, it further includes a resistor RT3, a voltage stabilizing diode TVS1, a fuse resistor FT1, a capacitor CT1 and a capacitor CT2;

[0026] A first end of the fuse resistor FT1 is electrically connected to the positive terminal of the charger, a second end of the fuse resistor FT1 is electrically connected to the first end of the resistor RT3, the cathode of the Zener diode TVS1, the first end of the capacitor CT1, the cathode of the Zener diode ZT1, and the cathode of the Zener diode ZT3, a second end of the capacitor CT1 is electrically connected to the first end of the capacitor CT2, a second end of the capacitor CT2, the second end of the resistor RT3, and the anode of the Zener diode TVS1 are all electrically connected to the negative terminal of the charger.

[0027] Optionally, the capacitor CT0 , the capacitor CT1 , the capacitor CT2 , and the capacitor CT12 are all non-polarized capacitors.

[0028] In a second aspect, the present invention further provides a DC power supply comprising a charger and a power transmission line, wherein the positive input end of the power transmission line is electrically connected to the positive terminal of the charger, the negative input end of the power transmission line is electrically connected to the negative terminal of the charger, the positive output end of the power transmission line is electrically connected to the positive input end of a battery module, and the negative output end of the power transmission line is electrically connected to the negative input end of the battery module; a negative main N-MOS switch component is electrically connected between the negative input end and the negative output end of the power transmission line;

[0029] The transmission line is provided with a negative electrode N-MOS fast shutdown circuit as described above.

[0030] Optionally, the negative electrode main N-MOS switch component includes an N-MOS transistor MT1 and an N-MOS transistor MT2;

[0031] The gate of the N-MOS transistor MT1 is electrically connected to the first end of the resistor RT64 via the resistor RT8. The gate of the N-MOS transistor MT2 is electrically connected to the first end of the resistor RT64 via the resistor RT9. The source of the N-MOS transistor MT1 and the source of the N-MOS transistor MT2 are both electrically connected to the negative terminal of the switch transistor QT4. The drain of the N-MOS transistor MT1 is electrically connected to the negative terminal of the switch transistor QT5.

[0032] The positive terminal of the switch tube QT6 is used to electrically connect to the positive input terminal of the battery module, and the drain of the N-MOS tube MT2 is used to electrically connect to the negative input terminal of the battery module.

[0033] Optionally, the negative main N-MOS switch component further includes a resistor RT7 and a Zener diode ZT2;

[0034] The cathode of the Zener diode ZT2 and the first end of the resistor RT7 are both electrically connected to the first end of the resistor RT64 , and the anode of the Zener diode ZT2 and the second end of the resistor RT7 are both electrically connected to the negative terminal of the switch tube QT4 ;

[0035] The drain of the N-MOS transistor MT1 is also electrically connected to the first end of the capacitor CT3 , the second end of the capacitor CT3 is electrically connected to the first end of the capacitor CT4 , and the second end of the capacitor CT4 is electrically connected to the drain of the N-MOS transistor MT2 .

[0036] Optionally, both capacitor CT3 and capacitor CT4 are non-polarized capacitors.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The negative electrode N-MOS fast shutdown circuit provided by the present invention can quickly shut down the main N-MOS switch component when the input voltage of the transmission line is abnormal (overvoltage / undervoltage). The control logic is simple and reliable, and there is basically no shutdown delay, which can effectively suppress the impact of transient large current on the device.

[0039] The present invention has other features and advantages that will be apparent from or will be described in detail in the accompanying drawings and the following detailed description incorporated herein, which together serve to explain certain principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 The diagram is a schematic diagram of a circuit structure of a DC power transmission line provided by an embodiment of the present invention.

[0042] Figure 2 This is a circuit structure diagram of a portion of a negative electrode N-MOS fast shutdown circuit provided by an embodiment of the present invention.

[0043] Figure 3 This is another circuit structure diagram of a negative electrode N-MOS fast shutdown circuit provided by an embodiment of the present invention.

[0044] Figure 4 This is a circuit structure diagram of a negative main N-MOS switch component provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to explain in detail the possible application scenarios, technical principles, specific solutions that can be implemented, and the purpose and effects of this application, the following is a detailed description of the specific embodiments listed in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of this application and are therefore only examples and are not intended to limit the scope of protection of this application.

[0046] References to "embodiments" herein mean that the specific features, structures, or characteristics described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the word "embodiment" in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the various technical features mentioned in the embodiments can be combined in any manner to form a corresponding implementable technical solution.

[0047] Unless otherwise defined, the technical terms used herein have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms herein is only for describing specific embodiments and is not intended to limit this application.

[0048] In the description of this application, the term "and / or" is used to describe a logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and both A and B exist. In addition, the character " / " in this document generally indicates that the objects before and after are in a logical "or" relationship.

[0049] In this application, terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantity, priority or sequence relationship between these entities or operations.

[0050] Without further limitations, in this application, the words "include", "comprise", "have" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those defined elements, but also other elements not explicitly listed, or elements inherent to such process, method or product.

[0051] Consistent with the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceed" are understood to exclude the number itself; expressions such as "above," "below," and "within" are understood to include the number itself. Furthermore, in the description of the embodiments of this application, "multiple" means more than two (including two), and similar expressions related to "multiple" are also understood in this manner, such as "multiple groups," "multiple times," etc., unless otherwise specifically defined.

[0052] In the description of the embodiments of the present application, the space-related expressions used, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or position relationship based on the orientation or position relationship shown in the specific embodiments or drawings, and are only for the convenience of describing the specific embodiments of the present application or facilitating the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, it should not be understood as a limitation on the embodiments of the present application.

[0053] Unless otherwise expressly specified or limited, in the description of the embodiments of the present application, the terms "installed", "connected", "connected", "fixed", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integrated setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art of the present application, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0054] Example 1:

[0055] See also Figure 1-Figure 4 , Figure 1 This is a schematic diagram of a circuit structure of a DC power transmission line provided by an embodiment of the present invention. Figure 2 This is a circuit structure diagram of a portion of a negative electrode N-MOS fast shutdown circuit provided by an embodiment of the present invention. Figure 3 This is another circuit structure diagram of a negative N-MOS fast shutdown circuit provided by an embodiment of the present invention. Figure 4 This is a circuit structure diagram of a negative main N-MOS switch component provided by an embodiment of the present invention.

[0056] It should be noted that, for ease of explanation, in this embodiment, unless otherwise specified, the "first end" generally refers to the upper end or left end of the electronic component, and the "second end" refers to the lower end or right end of the electronic component.

[0057] like Figure 1 As shown, the negative electrode N-MOS fast shutdown circuit includes an over-voltage and under-voltage protection unit and a fast shutdown unit;

[0058] Further, see Figure 2 , the fast shutdown unit includes a switch tube QT3, a switch tube QT4 and a switch tube QT6;

[0059] The control end of the switch tube QT6 is electrically connected to the drive signal output end of the over-voltage and under-voltage protection unit (ie Figure 2 VB terminal), the positive terminal of the switch tube QT6 is electrically connected to the positive terminal of the charger, the negative terminal of the switch tube QT6 is electrically connected to the first end of the resistor RT15 and the first end of the resistor RT66, the second end of the resistor RT66 is electrically connected to the anode of the diode DT1, and the cathode of the diode DT1 is electrically connected to the first end of the capacitor CT12, the first end of the resistor RT61, and the first end of the resistor RT63;

[0060] The second end of resistor RT15 is electrically connected to the control terminal of switch QT3. The positive terminal of switch QT3 is electrically connected to the first end of resistor RT59. The second end of resistor RT59 is electrically connected to the control terminal of switch QT4 and the second end of resistor RT61, respectively. The negative terminal of switch QT3 and the second end of capacitor CT12 are both electrically connected to the negative terminal of switch QT4 (connected to reference ground MGND). The second end of resistor RT63 is electrically connected to the first end of resistor RT64, and the second end of resistor RT64 is electrically connected to the positive terminal of switch QT4. The second end of resistor RT64 is also electrically connected to the control terminal of the negative main N-MOS switch component (i.e., Figure 2 middle MVgs terminal);

[0061] When the input voltage of the over-voltage / under-voltage protection unit is between the preset over-voltage threshold and the preset under-voltage threshold, the driving signal output terminal outputs a first driving signal to control the switch tubes QT6, QT3, and QT4 to be turned on, thereby controlling the main N-MOS switch component to be turned on;

[0062] When the input voltage of the over / under voltage protection unit exceeds the overvoltage threshold or is less than the undervoltage threshold, the drive signal output terminal does not output the first drive signal, and the switch tubes QT6, QT3 and QT4 are all turned off or non-conducting, thereby controlling the main N-MOS switch component to be turned off or non-conducting.

[0063] For example, in this embodiment, the overvoltage threshold is 33V, the undervoltage threshold is 11V, the switch tubes QT3 and QT4 are NPN transistors, and the switch tube QT6 is a PNP transistor;

[0064] When the input voltage of the DC power supply transmission line is normal, that is, the positive terminal of the charger (i.e. Figure 2 Charge+ terminal) and negative terminal (i.e. Figure 2 When the voltage between the Charge-terminal in the MVgs terminal is between 11V and 33V, the VB terminal will output a low-level signal, turning on the switch tube QT6, thereby turning on the switch tubes QT3 and QT4 in sequence. At this time, the MVgs terminal outputs a high-level signal, turning on the main N-MOS switch component;

[0065] When the input voltage of the DC power supply transmission line is abnormal, that is, the positive terminal of the charger (i.e. Figure 2 Charge+ terminal) and negative terminal (i.e. Figure 2 When the voltage between the Charge-terminal in the MVgs pin and the Charge-terminal in the MVgs pin is not between 11V and 33V (overvoltage or undervoltage), the VB terminal will no longer output a low-level signal, and the switch tube QT6 will be turned off or non-conducting, and then the switch tubes QT3 and QT4 will also be turned off or non-conducting. The capacitor C12 will discharge quickly to lower the voltage of the MVgs terminal, causing the main N-MOS switch component to be turned off or non-conducting.

[0066] For example, in this embodiment, capacitor C12 is a 100nF capacitor. The discharge time of capacitor C12 is very fast, and there is basically no shutdown time delay. Therefore, the negative electrode N-MOS fast shutdown circuit can quickly shut down the main N-MOS switch component with basically no shutdown delay, and can effectively suppress the impact of transient large current on the device.

[0067] As a preferred embodiment, a resistor RT60 is further electrically connected between the control terminal of the switch tube QT3 and the negative terminal of the switch tube QT3, a resistor RT62 is further electrically connected between the control terminal of the switch tube QT4 and the negative terminal of the switch tube QT4, and a resistor RT14 is further electrically connected between the control terminal of the switch tube QT6 and the positive terminal of the switch tube QT6.

[0068] Further, if Figure 3 As shown, the over-voltage and under-voltage protection unit includes a switch tube QT2, a switch tube QT5, a Zener diode ZT1 and a Zener diode ZT3;

[0069] The cathode of the Zener diode ZT1 is electrically connected to the cathode of the Zener diode ZT3 and the positive terminal of the switch QT6, respectively. The anode of the Zener diode ZT1 is electrically connected to the first end of the resistor RT10. The second end of the resistor RT10 is electrically connected to the first end of the resistor RT11 and the control terminal of the switch QT2, respectively. The negative terminal of the switch QT2 and the second end of the resistor RT11 are both electrically connected to the negative terminal of the charger.

[0070] The anode of the Zener diode ZT3 is electrically connected to the first end of the resistor RT6. The second end of the resistor RT6 is electrically connected to the first end of the resistor R65, the first end of the capacitor CT0, the first end of the resistor RT12, and the control end of the switch QT5. The positive terminal of the switch QT2 is electrically connected to the second end of the resistor R65. The negative terminal of the switch QT5, the second end of the capacitor CT0, and the second end of the resistor RT12 are all electrically connected to the negative terminal of the charger.

[0071] The positive terminal of the switch tube QT5 is electrically connected to the control terminal of the switch tube QT6 through the resistor RT13.

[0072] For example, in this embodiment, the switch tube QT2 and the switch tube QT5 are both NPN transistors; the voltage regulator diode ZT1 is a 33V voltage regulator diode, and the voltage regulator diode ZT3 is an 11V voltage regulator diode;

[0073] When the input voltage of the transmission line is greater than 33V, both the Zener diodes ZT1 and ZT3 are turned on. At this time, the switch tube QT2 is turned on, pulling down the base voltage of the switch tube QT5, and the switch tube QT5 is cut off or does not conduct.

[0074] When the input voltage of the transmission line is greater than 11V but less than 33V, the Zener diode ZT1 is not conducting, the Zener diode ZT3 is conducting, the switch tube QT2 is cut off or not conducting, and the base of the switch tube QT5 is connected to a high-level signal, so the switch tube QT5 is conducting;

[0075] When the input voltage of the transmission line is less than 11V, the Zener diode ZT1 and the Zener diode ZT3 are both non-conductive, and the switch tube QT2 and the switch tube QT5 are both cut off or non-conductive.

[0076] In addition, when the charger is reversed, it is equivalent to the Charge- terminal being connected to a high level. Since the conduction condition of the NPN transistor is V B The voltage must be greater than V E Therefore, the switch tube QT2 and the switch tube QT5 are both cut off or non-conducting. At this time, the main N-MOS switch component is turned off or non-conducting, so the negative electrode N-MOS fast shutdown circuit can also play a role in preventing reverse connection.

[0077] Furthermore, if Figure 3As shown, the first end of the fuse resistor FT1 is electrically connected to the positive terminal of the charger, the second end of the fuse resistor FT1 is electrically connected to the first end of the resistor RT3, the cathode of the Zener diode TVS1, the first end of the capacitor CT1, the cathode of the Zener diode ZT1 and the cathode of the Zener diode ZT3, the second end of the capacitor CT1 is electrically connected to the first end of the capacitor CT2, the second end of the capacitor CT2, the second end of the resistor RT3 and the anode of the Zener diode TVS1 are all electrically connected to the negative terminal of the charger.

[0078] In this embodiment, capacitors CT0, CT1, CT2, and CT12 are all non-polarized capacitors. More specifically, in this embodiment, capacitor CT0 uses a 2.2 microfarad capacitor, which only takes a few microseconds to discharge, while capacitor CT12 uses a 100nF capacitor, which has an even faster discharge time with virtually no delay.

[0079] In summary, the negative N-MOS fast shutdown circuit provided in this embodiment solves at least the following problems:

[0080] 1. It can simultaneously realize the functions of anti-reverse connection and fast shutdown, and the circuit structure and control logic are simple and reliable. There is no contradiction between efficiency and loss, and no need to stack additional independent modules. It not only reduces the production cost but also meets the needs of high-efficiency equipment.

[0081] 2. It does not rely on multi-level detection and logic processing, has a fast response speed, and can effectively suppress the impact of transient large current on the device;

[0082] 3. The adaptability to voltage fluctuations or load changes is significantly enhanced, and it has good stability within a wide input voltage range.

[0083] Example 2:

[0084] This embodiment provides a DC power supply, a DC power supply including a charger and a transmission line, wherein the positive input end of the transmission line is electrically connected to the positive terminal of the charger, the negative input end of the transmission line is electrically connected to the negative terminal of the charger, the positive output end of the transmission line is used to electrically connect to the positive input end of the battery module, and the negative output end of the transmission line is used to electrically connect to the negative input end of the battery module;

[0085] A negative main N-MOS switch component is electrically connected between the negative input terminal and the negative output terminal of the transmission line;

[0086] A negative electrode N-MOS fast shutdown circuit as described in the first embodiment is provided on the transmission line.

[0087] Further, if Figure 4 As shown, the negative main N-MOS switch component includes an N-MOS transistor MT1 and an N-MOS transistor MT2;

[0088] The gate of the N-MOS transistor MT1 is electrically connected to the first end of the resistor RT64 via the resistor RT8. The gate of the N-MOS transistor MT2 is electrically connected to the first end of the resistor RT64 via the resistor RT9. The source of the N-MOS transistor MT1 and the source of the N-MOS transistor MT2 are both electrically connected to the negative terminal of the switch transistor QT4. The drain of the N-MOS transistor MT1 is electrically connected to the negative terminal of the switch transistor QT5.

[0089] The positive terminal of the switch tube QT6 is used to electrically connect to the positive input terminal of the battery module, and the drain of the N-MOS tube MT2 is used to electrically connect to the negative input terminal of the battery module.

[0090] As a preferred embodiment, the negative main N-MOS switch component further includes a resistor RT7 and a Zener diode ZT2;

[0091] The cathode of the Zener diode ZT2 and the first end of the resistor RT7 are both electrically connected to the first end of the resistor RT64 , and the anode of the Zener diode ZT2 and the second end of the resistor RT7 are both electrically connected to the negative terminal of the switch tube QT4 ;

[0092] The drain of the N-MOS transistor MT1 is also electrically connected to the first end of the capacitor CT3 , the second end of the capacitor CT3 is electrically connected to the first end of the capacitor CT4 , and the second end of the capacitor CT4 is electrically connected to the drain of the N-MOS transistor MT2 .

[0093] In this embodiment, the capacitor CT3 and the capacitor CT4 are both non-polarized capacitors.

[0094] Since the negative electrode N-MOS fast turn-off circuit has been described in detail in the first embodiment, it will not be described again in this embodiment.

[0095] The present embodiment provides a DC power supply that integrates reverse connection protection and fast shutdown functions. The circuit is simple and reliable, and has high efficiency, reliability, and economy.

[0096] It should be noted that this embodiment only provides a relatively detailed description of the technical solutions closely related to this embodiment. Although some related circuits are not explained, it should not affect the implementation of the technical solutions of this embodiment by those skilled in the art. These contents should be able to understand their implementation principles through the circuits in the accompanying drawings or conventional technical means in this field, so they will not be repeated in this embodiment.

[0097] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A negative N-MOS fast shutdown circuit, characterized in that: Including over-voltage and under-voltage protection unit and fast shutdown unit; The fast shutdown unit includes a switch tube QT3, a switch tube QT4 and a switch tube QT6; The control terminal of the switch tube QT6 is electrically connected to the drive signal output terminal of the over-voltage and under-voltage protection unit, the positive terminal of the switch tube QT6 is electrically connected to the positive terminal of the charger, the negative terminal of the switch tube QT6 is electrically connected to the first end of the resistor RT15 and the first end of the resistor RT66, the second end of the resistor RT66 is electrically connected to the anode of the diode DT1, and the cathode of the diode DT1 is electrically connected to the first end of the capacitor CT12, the first end of the resistor RT61, and the first end of the resistor RT63, respectively; The second end of resistor RT15 is electrically connected to the control terminal of switch QT3. The positive terminal of switch QT3 is electrically connected to the first end of resistor RT59. The second end of resistor RT59 is electrically connected to the control terminal of switch QT4 and the second end of resistor RT61, respectively. The negative terminal of switch QT3 and the second end of capacitor CT12 are both electrically connected to the negative terminal of switch QT4. The second end of resistor RT63 is electrically connected to the first end of resistor RT64, and the second end of resistor RT64 is electrically connected to the positive terminal of switch QT4. The second end of resistor RT64 is also electrically connected to the control terminal of the negative main N-MOS switch component. When the input voltage of the over-voltage / under-voltage protection unit is between a preset over-voltage threshold and a preset under-voltage threshold, the drive signal output terminal outputs a first drive signal to control the switch tubes QT6, QT3, and QT4 to be turned on, thereby controlling the main N-MOS switch component to be turned on; When the input voltage of the over-voltage / under-voltage protection unit exceeds the overvoltage threshold or is less than the undervoltage threshold, the drive signal output end does not output the first drive signal, and the switch tubes QT6, QT3, and QT4 are all turned off or non-conducting, thereby controlling the main N-MOS switch component to be turned off or non-conducting.

2. The negative electrode N-MOS fast shutdown circuit according to claim 1, characterized in that: A resistor RT60 is electrically connected between the control terminal of the switch tube QT3 and the negative terminal of the switch tube QT3 , a resistor RT62 is electrically connected between the control terminal of the switch tube QT4 and the negative terminal of the switch tube QT4 , and a resistor RT14 is electrically connected between the control terminal of the switch tube QT6 and the positive terminal of the switch tube QT6 .

3. The negative electrode N-MOS fast shutdown circuit according to claim 2, characterized in that: The over-voltage and under-voltage protection unit includes a switch tube QT2, a switch tube QT5, a voltage stabilizing diode ZT1 and a voltage stabilizing diode ZT3; The cathode of the Zener diode ZT1 is electrically connected to the cathode of the Zener diode ZT3 and the positive terminal of the switch QT6, respectively. The anode of the Zener diode ZT1 is electrically connected to the first end of the resistor RT10. The second end of the resistor RT10 is electrically connected to the first end of the resistor RT11 and the control terminal of the switch QT2, respectively. The negative terminal of the switch QT2 and the second end of the resistor RT11 are both electrically connected to the negative terminal of the charger. The anode of the Zener diode ZT3 is electrically connected to the first end of the resistor RT6. The second end of the resistor RT6 is electrically connected to the first end of the resistor R65, the first end of the capacitor CT0, the first end of the resistor RT12, and the control end of the switch QT5. The positive terminal of the switch QT2 is electrically connected to the second end of the resistor R65. The negative terminal of the switch QT5, the second end of the capacitor CT0, and the second end of the resistor RT12 are all electrically connected to the negative terminal of the charger. The positive terminal of the switch tube QT5 is electrically connected to the control terminal of the switch tube QT6 through the resistor RT13.

4. The negative electrode N-MOS fast shutdown circuit according to claim 3, characterized in that: The switch tubes QT2 , QT3 , QT4 and QT5 are all NPN transistors, and the switch tube QT6 is a PNP transistor.

5. The negative electrode N-MOS fast shutdown circuit according to claim 3, characterized in that: It also includes a resistor RT3, a voltage stabilizing diode TVS1, a fuse resistor FT1, a capacitor CT1, and a capacitor CT2; A first end of the fuse resistor FT1 is electrically connected to the positive terminal of the charger, a second end of the fuse resistor FT1 is electrically connected to the first end of the resistor RT3, the cathode of the Zener diode TVS1, the first end of the capacitor CT1, the cathode of the Zener diode ZT1, and the cathode of the Zener diode ZT3, a second end of the capacitor CT1 is electrically connected to the first end of the capacitor CT2, a second end of the capacitor CT2, the second end of the resistor RT3, and the anode of the Zener diode TVS1 are all electrically connected to the negative terminal of the charger.

6. The negative electrode N-MOS fast shutdown circuit according to claim 5, characterized in that: Capacitor CT0 , capacitor CT1 , capacitor CT2 , and capacitor CT12 are all non-polarized capacitors.

7. A DC power supply comprising a charger and a transmission line, wherein the positive input end of the transmission line is electrically connected to the positive terminal of the charger, the negative input end of the transmission line is electrically connected to the negative terminal of the charger, the positive output end of the transmission line is electrically connected to the positive input end of a battery module, and the negative output end of the transmission line is electrically connected to the negative input end of the battery module; characterized in that: A negative main N-MOS switch component is electrically connected between the negative input terminal and the negative output terminal of the power transmission line; The transmission line is provided with a negative electrode N-MOS fast shutdown circuit as described in any one of claims 1 to 6.

8. The DC power supply according to claim 7, characterized in that: The negative electrode main N-MOS switch component includes an N-MOS tube MT1 and an N-MOS tube MT2; The gate of the N-MOS transistor MT1 is electrically connected to the first end of the resistor RT64 via the resistor RT8. The gate of the N-MOS transistor MT2 is electrically connected to the first end of the resistor RT64 via the resistor RT9. The source of the N-MOS transistor MT1 and the source of the N-MOS transistor MT2 are both electrically connected to the negative terminal of the switch transistor QT4. The drain of the N-MOS transistor MT1 is electrically connected to the negative terminal of the switch transistor QT5. The positive terminal of the switch tube QT6 is used to electrically connect to the positive input terminal of the battery module, and the drain of the N-MOS tube MT2 is used to electrically connect to the negative input terminal of the battery module.

9. A DC power supply according to claim 8, characterized in that: The negative main N-MOS switch component also includes a resistor RT7 and a Zener diode ZT2; The cathode of the Zener diode ZT2 and the first end of the resistor RT7 are both electrically connected to the first end of the resistor RT64 , and the anode of the Zener diode ZT2 and the second end of the resistor RT7 are both electrically connected to the negative terminal of the switch tube QT4 ; The drain of the N-MOS transistor MT1 is also electrically connected to the first end of the capacitor CT3 , the second end of the capacitor CT3 is electrically connected to the first end of the capacitor CT4 , and the second end of the capacitor CT4 is electrically connected to the drain of the N-MOS transistor MT2 .

10. A DC power supply according to claim 9, characterized in that: Capacitor CT3 and capacitor CT4 are both non-polarized capacitors.

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