Port voltage stabilization protection circuit
By using a combination of transistors, MOS tubes and voltage stabilization diodes in the port protection circuit to set the output voltage range, the over-undervoltage problem that cannot be effectively protected in the prior art is solved, and the voltage stabilization protection and voltage over-voltage of vehicle-mounted products are achieved Undervoltage protection function.
Patent Information
- Application Number
- CN202420790776.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-16
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2034-04-16
AI Technical Summary
The existing port protection circuit cannot effectively protect the load in the face of long-term overvoltage, and lacks undervoltage protection function, which affects the safety of automotive products.
A port voltage stabilization protection circuit is designed, and the output voltage range is set through the combination of transistors, MOS tubes, resistors and voltage stabilization diodes to realize the over-voltage protection function. The specific implementation method is: when the voltage is less than the undervoltage threshold, the transistor and the MOS are in the off state; when the voltage is between the undervoltage and the overvoltage threshold, a stable output is provided; when the voltage exceeds the overvoltage threshold, the voltage stabilizing diode Working, the MOS tube is turned on, and the voltage is clamped.
The voltage stabilization protection of the load is achieved, ensuring stable voltage output is provided under different voltage conditions, avoiding load damage, and having over-voltage protection function.
Smart Images
Figure CN222355968U_ABST
Abstract
Description
[Technical field]
[0001] The utility model relates to the technical field of port protection circuits, in particular to a port voltage stabilization protection circuit. [Background technology]
[0002] Because the voltage supply level of the vehicle battery fluctuates greatly under some extreme working conditions, and the operating voltage range of many load products is relatively small, the fluctuating power supply voltage will cause irreversible damage to the back-end load, and in severe cases will affect the safety of automotive products.
[0003] The existing port protection circuit generally absorbs the voltage by setting TVS (Transient Voltage Suppressor) and Zener diodes at the product input. These components can generally only bear short-term overvoltage, but long-term overvoltage and undervoltage can only be resisted by load components, which will cause certain damage to the load circuit. And simply applying these components does not have the undervoltage protection function.
[0004] Therefore, it is necessary to propose a new technical solution to solve the above problems. [Contents of the utility model]
[0005] One of the purposes of the utility model is to provide a port voltage stabilization protection circuit, which can be used in port protection of vehicle-mounted products. The output voltage range of its output terminal Vout1 can be set according to the power supply voltage range of the load by matching and selecting components such as resistors, so as to provide a stable voltage output for the rear-end load.
[0006] According to one aspect of the utility model, the utility model provides a port voltage stabilization protection circuit, which includes a transistor Q1, a transistor Q2, a MOS tube Q3, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a voltage stabilization diode D1, one end of the resistor R1 is connected to the voltage input terminal Vin, and the other end thereof is connected to the connection node A; one end of the resistor R2 is connected to the connection node A, and the other end thereof is grounded; the first connection end of the transistor Q1 is connected to the voltage input terminal Vin, and the second connection end thereof is connected to the connection node B The first connection end of the transistor Q2 is connected to the control end of the transistor Q1 through the resistor R3, the control end thereof is connected to the connection node A, and the second connection end thereof is grounded; one end of the resistor R4 is connected to the connection node B, and the other end thereof is connected to the connection node C; the cathode of the voltage zener diode D1 is connected to the connection node C, and the anode thereof is grounded; the first connection end of the MOS transistor Q3 is connected to the connection node B, the control end thereof is connected to the connection node C, and the second connection end thereof is connected to the voltage output terminal Vout1.
[0007] Further, when the voltage of the voltage input terminal Vin is less than the undervoltage threshold, the transistor Q1 is turned off and the transistor Q2 is turned off; when the voltage of the voltage input terminal Vin is greater than the undervoltage threshold and less than the overvoltage threshold, the transistor Q1 is turned on, the transistor Q2 is turned on, the MOS transistor Q3 is turned on, and the voltage regulator diode D1 does not work; when the voltage of the voltage input terminal Vin is greater than the overvoltage threshold, the transistor Q1 is turned on, the transistor Q2 is turned on, the MOS transistor Q3 is turned on, and the voltage regulator diode D1 works; wherein the undervoltage threshold is less than the overvoltage threshold.
[0008] Further, the transistor Q1 is a PNP transistor, and the first connection end, the second connection end and the control end of the transistor Q1 are respectively the emitter, the collector and the base of the PNP transistor; the transistor Q2 is an NPN transistor, and the first connection end, the second connection end and the control end of the transistor Q2 are respectively the collector, the emitter and the base of the NPN transistor; the MOS transistor Q3 is an NMOS transistor, and the first connection end, the second connection end and the control end of the MOS transistor Q3 are respectively the drain, the source and the gate of the NMOS transistor.
[0009] Furthermore, the undervoltage threshold value is set arbitrarily by matching the ratio of the resistor R1 and the resistor R2; and the overvoltage threshold value is set arbitrarily by selecting the resistor R4 and the voltage stabilizing diode D1.
[0010] Furthermore, the resistance values of the resistor R1 and the resistor R2 are selected to satisfy: when the voltage of the voltage input terminal Vin is less than the undervoltage threshold, the voltage value of the connection node A is less than the turn-on voltage value of the transistor Q2, so that the transistor Q2 is in a cut-off state; when the voltage of the voltage input terminal Vin is greater than the overvoltage threshold, the voltage value of the connection node A is greater than the turn-on voltage value of the transistor Q2, so that the transistor Q2 is in a conduction state; the selection of the resistor R4 and the Zener diode D1 satisfies: when the voltage of the voltage input terminal Vin is less than the overvoltage threshold, the Zener diode D1 does not work; when the voltage of the voltage input terminal Vin is greater than the overvoltage threshold, the Zener diode D1 works.
[0011] Furthermore, the voltage input terminal Vin is connected to an output port of a vehicle battery, and the voltage output terminal Vout1 is connected to a load.
[0012] Compared with the prior art, the utility model can be applied to port protection of vehicle-mounted products. The output voltage range of the output terminal Vout1 can be set according to the supply voltage range of the load by selecting components such as resistors, thereby providing a stable voltage output for the rear-end load.
Brief Description of the Drawings
[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:
[0014] Figure 1 The diagram is a circuit diagram of a port voltage stabilizing protection circuit in one embodiment of the utility model. [Specific implementation method]
[0015] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0016] The "one embodiment" or "embodiment" referred to herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the utility model. The "in one embodiment" that appears in different places in this specification does not all refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments. Unless otherwise specified, the words "coupled", "connected", "connected" and "connected" in this document that indicate electrical connection all mean direct or indirect connection. For example, A is connected to B, which includes both direct electrical connection between A and B and connection between A and B through electrical components or circuits.
[0017] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "front", "back", "left", "right", "vertical", "perpendicular", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0018] Please refer to Figure 1 As shown, it is a circuit diagram of a port voltage stabilizing protection circuit in one embodiment of the utility model. Figure 1 The port voltage stabilizing protection circuit shown includes a transistor Q1, a transistor Q2, a MOS tube (Metal-Oxide-Semiconductor Field-Effect Transistor, i.e., a metal-oxide semiconductor field effect transistor) Q3, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a voltage stabilizing diode D1.
[0019] One end of the resistor R1 is connected to the voltage input terminal Vin, and the other end thereof is connected to the connection node A; one end of the resistor R2 is connected to the connection node A, and the other end thereof is grounded; a first connection end of the transistor Q1 is connected to the voltage input terminal Vin, and a second connection end thereof is connected to the connection node B; a first connection end of the transistor Q2 is connected to the control end of the transistor Q1 via the resistor R3, the control end thereof is connected to the connection node A, and the second connection end thereof is grounded; one end of the resistor R4 is connected to the connection node B, and the other end thereof is connected to the connection node C; a cathode of the voltage zener diode D1 is connected to the connection node C, and a positive electrode thereof is grounded; a first connection end of the MOS transistor Q3 is connected to the connection node B, a control end thereof is connected to the connection node C, and a second connection end thereof is connected to the voltage output terminal Vout1.
[0020] exist Figure 1 In the specific embodiment shown, the transistor Q1 is a PNP transistor, and the first connection end, the second connection end and the control end of the transistor Q1 are respectively the emitter, the collector and the base of the PNP transistor; the transistor Q2 is an NPN transistor, and the first connection end, the second connection end and the control end of the transistor Q2 are respectively the collector, the emitter and the base of the NPN transistor; the MOS transistor Q3 is an NMOS (N-Metal-Oxide-Semiconductor) transistor, and the first connection end, the second connection end and the control end of the MOS transistor Q3 are respectively the drain, the source and the gate of the NMOS transistor.
[0021] exist Figure 1 In the port voltage stabilization protection circuit shown, when the voltage at the voltage input terminal Vin is less than the undervoltage threshold, transistor Q1 is turned off and transistor Q2 is turned off; when the voltage at the voltage input terminal Vin is greater than the undervoltage threshold and less than the overvoltage threshold, transistor Q1 is turned on, transistor Q2 is turned on, MOS transistor Q3 is turned on, and voltage stabilization diode D1 does not work; when the voltage at the voltage input terminal Vin is greater than the overvoltage threshold, transistor Q1 is turned on, transistor Q2 is turned on, MOS transistor Q3 is turned on, and voltage stabilization diode D1 works. Among them, the undervoltage threshold is less than the overvoltage threshold.
[0022] Correspondingly, any undervoltage threshold can be set by matching the ratio of resistors R1 and R2; any overvoltage threshold can be set by selecting resistor R4 and voltage stabilizing diode D1. Specifically, the selection of the resistance values of resistors R1 and R2 satisfies: when the voltage of the voltage input terminal Vin is less than the undervoltage threshold, the voltage value of the connection node A is less than the turn-on voltage value of transistor Q2, so that transistor Q2 is in the cut-off state; when the voltage of the voltage input terminal Vin is greater than the overvoltage threshold, the voltage value of the connection node A is greater than the turn-on voltage value of transistor Q2, so that transistor Q2 is in the on state; the selection of resistor R4 and voltage stabilizing diode D1 satisfies: when the voltage of the voltage input terminal Vin is less than the overvoltage threshold, the voltage stabilizing diode D1 does not work; when the voltage of the voltage input terminal Vin is greater than the overvoltage threshold, the voltage stabilizing diode D1 works.
[0023] The following is a detailed introduction Figure 1 The working principle of the port voltage regulation protection circuit shown in FIG.
[0024] When the voltage at the voltage input terminal Vin is less than the under-voltage threshold, the voltage at the voltage input terminal Vin is divided by the resistance ratio of the resistors R1 and R2, and the voltage value of the connection node A is less than the turn-on voltage value of the transistor Q2, so that the transistor Q2 cannot be turned on (i.e., it is in the cut-off state). If the transistor Q2 cannot be turned on, the base of the transistor Q1 cannot form a loop, so the transistor Q1 will not be turned on (i.e., it is in the cut-off state), and the voltage output terminal Vout1 will have no output under the condition of under-voltage.
[0025] When the voltage at the voltage input terminal Vin is greater than the undervoltage threshold but less than the overvoltage threshold, the voltage value of the connection node A is greater than the turn-on voltage value of the transistor Q2, so that the transistor Q2 is turned on, and the turned-on transistor Q2 pulls the gate of the transistor Q1 down to the ground level, so that the transistor Q1 is turned on. Since the voltage at the voltage input terminal Vin does not exceed the overvoltage threshold, the voltage regulator D1 does not work. At this time, the gate voltage of the MOS tube Q3 is equal to the voltage of the voltage input terminal Vin, the MOS tube Q3 can be turned on, and the voltage output terminal Vout1 normally outputs the voltage of the voltage input terminal Vin.
[0026] When the voltage at the voltage input terminal Vin is greater than the overvoltage threshold voltage, transistors Q1 and Q2 can work normally (i.e., they are turned on). Since the voltage at the voltage input terminal Vin exceeds the overvoltage threshold, the voltage regulator D1 works. At this time, the gate voltage of the MOS tube Q3 will be clamped to the overvoltage threshold, so the voltage output terminal Vout1 will output a voltage close to the overvoltage threshold.
[0027] so, Figure 1 The port voltage stabilization protection circuit shown can realize over-voltage and under-voltage protection functions, and provide a stable voltage output for the load at the back end.
[0028] In one embodiment, Figure 1 The port voltage stabilization protection circuit shown can be applied to port protection of vehicle-mounted products. Specifically, the voltage input terminal Vin is connected to the vehicle-mounted battery output port, and the voltage output terminal Vout1 is connected to the load.
[0029] The innovative features and corresponding beneficial effects of the utility model are as follows:
[0030] 1) The matching ratio of resistors R1 and R2 can set any undervoltage threshold point, and the selection of resistors R4 and D1 can set any overvoltage threshold point.
[0031] 2) Ordinary TVS and voltage regulator circuits cannot withstand long-term overvoltage operation. This design uses MOS tube Q3 to absorb most of the energy and provide a tolerable voltage for the rear-end load.
[0032] To sum up, the port voltage stabilization protection circuit provided by the utility model can be used in port protection of vehicle-mounted products. The output voltage range of its output terminal Vout1 can be set according to the power supply voltage range of the load by selecting components such as resistors, thereby providing a stable voltage output for the rear-end load.
[0033] It should be noted that any changes made by those skilled in the art to the specific implementation of the present invention do not deviate from the scope of the claims of the present invention. Accordingly, the scope of the claims of the present invention is not limited to the aforementioned specific implementation.
Claims
1. A port voltage stabilization protection circuit, characterized in that: It includes transistor Q1, transistor Q2, MOS tube Q3, resistor R1, resistor R2, resistor R3, resistor R4 and voltage stabilizing diode D1. One end of the resistor R1 is connected to the voltage input terminal Vin, and the other end thereof is connected to the connection node A; one end of the resistor R2 is connected to the connection node A, and the other end thereof is grounded; the first connection end of the transistor Q1 is connected to the voltage input terminal Vin, and the second connection end thereof is connected to the connection node B; the first connection end of the transistor Q2 is connected to the control end of the transistor Q1 via the resistor R3, the control end thereof is connected to the connection node A, and the second connection end thereof is grounded; one end of the resistor R4 is connected to the connection node B, and the other end thereof is connected to the connection node C; the cathode of the voltage zener diode D1 is connected to the connection node C, and the anode thereof is grounded; the first connection end of the MOS transistor Q3 is connected to the connection node B, the control end thereof is connected to the connection node C, and the second connection end thereof is connected to the voltage output terminal Vout1.
2. The port voltage stabilization protection circuit according to claim 1, characterized in that: When the voltage at the voltage input terminal Vin is less than the undervoltage threshold, the transistor Q1 is turned off and the transistor Q2 is turned off; When the voltage at the voltage input terminal Vin is greater than the undervoltage threshold and less than the overvoltage threshold, the transistor Q1 is turned on, the transistor Q2 is turned on, the MOS transistor Q3 is turned on, and the voltage regulator diode D1 does not work; When the voltage at the voltage input terminal Vin is greater than the overvoltage threshold, the transistor Q1 is turned on, the transistor Q2 is turned on, the MOS transistor Q3 is turned on, and the voltage regulator diode D1 works; Wherein, the undervoltage threshold is smaller than the overvoltage threshold.
3. The port voltage stabilizing protection circuit according to claim 2, characterized in that: The transistor Q1 is a PNP transistor, and the first connection end, the second connection end and the control end of the transistor Q1 are respectively the emitter, the collector and the base of the PNP transistor; The transistor Q2 is an NPN transistor, and the first connection end, the second connection end and the control end of the transistor Q2 are respectively the collector, the emitter and the base of the NPN transistor; The MOS transistor Q3 is an NMOS transistor, and the first connection terminal, the second connection terminal and the control terminal of the MOS transistor Q3 are respectively the drain, the source and the gate of the NMOS transistor.
4. The port voltage stabilizing protection circuit according to claim 3, characterized in that: By matching the resistor R1 and the resistor R2, any undervoltage threshold is set; The overvoltage threshold value can be set arbitrarily by selecting the resistor R4 and the voltage stabilizing diode D1.
5. The port voltage stabilizing protection circuit according to claim 4, characterized in that: The resistance values of the resistor R1 and the resistor R2 are selected to satisfy: when the voltage of the voltage input terminal Vin is less than the undervoltage threshold, the voltage value of the connection node A is less than the turn-on voltage value of the transistor Q2, so that the transistor Q2 is in a cut-off state; when the voltage of the voltage input terminal Vin is greater than the overvoltage threshold, the voltage value of the connection node A is greater than the turn-on voltage value of the transistor Q2, so that the transistor Q2 is in a conduction state; The resistor R4 and the Zener diode D1 are selected to satisfy the following conditions: when the voltage at the voltage input terminal Vin is less than the overvoltage threshold, the Zener diode D1 does not work; when the voltage at the voltage input terminal Vin is greater than the overvoltage threshold, the Zener diode D1 works.
6. The port voltage stabilizing protection circuit according to any one of claims 1 to 5, characterized in that: The voltage input terminal Vin is connected to the vehicle battery output port, The voltage output terminal Vout1 is connected to a load.