Input overvoltage and undervoltage protection circuit and electronic equipment

Abstract

The utility model relates to the technical field of voltage protection, in particular to an input overvoltage and undervoltage protection circuit and electronic equipment. The input end of an under-voltage identification module is connected with a voltage input end, the output end of the under-voltage identification module is connected with a first trigger end of a logic driving module, and a trigger threshold value of the first trigger end is set through a built-in voltage-regulator tube of the under-voltage identification module; the input end of the overvoltage identification module is connected with the voltage input end, the output end of the overvoltage identification module is connected with the second trigger end of the logic driving module, and a trigger threshold value of the second trigger end is set through a built-in voltage-regulator tube of the overvoltage identification module; the output end of the logic driving module is connected with the trigger end of the access control module, the input end is connected with the voltage input end, and the output end is connected with the voltage output end; when the input voltage value of the voltage input end is between the trigger threshold value of the first trigger end and the trigger threshold value of the second trigger end, the access control module is switched on. The beneficial effects of reducing the space occupation and the cost demand of the input overvoltage and undervoltage protection circuit and the electronic equipment can be realized.

Description

Technical Field

[0001] This application relates to the technical field of voltage protection, and more particularly to an input overvoltage and undervoltage protection circuit and electronic device. Background Technology

[0002] With the widespread adoption of consumer electronics, data center equipment, and other electronic products, the market is placing higher demands on the reliability and cost control of power management modules. Input overvoltage and undervoltage protection circuits, as core safety modules of power systems, must quickly cut off or adjust the input when voltage is abnormal to prevent damage to downstream circuits. Current technologies generally employ a composite control scheme of "Zenyl Regulator + Voltage Comparator," where a threshold reference is set by the Zener diode, and the comparator monitors the input voltage in real time and triggers protection actions.

[0003] However, this solution requires the integration of Zener diodes, comparators, and matching resistors and capacitors, significantly increasing circuit complexity and material costs. This is especially true in high-precision, multi-threshold scenarios, where the difficulty of component matching further drives up production costs. Therefore, reducing space requirements and cost has become a pressing technical challenge. Utility Model Content

[0004] To overcome the shortcomings of the prior art, this application provides an input overvoltage and undervoltage protection circuit and electronic device to reduce the space occupation and cost requirements of the input overvoltage and undervoltage protection circuit and electronic device.

[0005] The technical solution adopted by this application to solve its technical problem is:

[0006] In a first aspect, this application provides an input overvoltage and undervoltage protection circuit, including: an undervoltage identification module, an overvoltage identification module, a logic driving module, and a path control module;

[0007] The input terminal of the undervoltage identification module is connected to the voltage input terminal, and the output terminal of the undervoltage identification module is connected to the first trigger terminal of the logic drive module. The trigger threshold of the first trigger terminal is set through the built-in Zener diode of the undervoltage identification module.

[0008] The input terminal of the overvoltage identification module is connected to the voltage input terminal, and the output terminal of the overvoltage identification module is connected to the second trigger terminal of the logic drive module. The trigger threshold of the second trigger terminal is set through the built-in Zener diode of the overvoltage identification module.

[0009] The output terminal of the logic driving module is connected to the trigger terminal of the path control module, the input terminal of the path control module is connected to the voltage input terminal, and the output terminal of the path control module is connected to the voltage output terminal.

[0010] The path control module connects the voltage input terminal and the voltage output terminal only when the input voltage value of the voltage input terminal is between the trigger threshold of the first trigger terminal and the trigger threshold of the second trigger terminal.

[0011] Optionally, the undervoltage identification module includes a first resistor, a first Zener diode, and a second resistor;

[0012] One end of the first resistor is connected to the voltage input terminal, and the other end is connected to the negative terminal of the first Zener diode;

[0013] The positive terminal of the first Zener diode is connected to one end of the second resistor and the first trigger terminal of the logic drive module, and the other end of the second resistor is grounded.

[0014] Optionally, the overvoltage identification module includes a third resistor, a second Zener diode, and a fourth resistor; the breakdown voltage of the second Zener diode is configured differently from the breakdown voltage of the first Zener diode.

[0015] One end of the third resistor is connected to the voltage input terminal, and the other end is connected to the negative terminal of the second Zener diode. The positive terminal of the second Zener diode is grounded through the fourth resistor.

[0016] The two ends of the third resistor are connected to the second trigger terminal.

[0017] Optionally, the overvoltage identification module further includes a first capacitor;

[0018] The first capacitor is connected in parallel across the three ends of the third resistor.

[0019] Optionally, the logic driving module includes a first transistor, a fifth resistor, a second transistor, and a sixth resistor;

[0020] The base of the first transistor is connected to the junction of the first Zener diode and the second resistor; the collector of the first transistor is connected to one end of the fifth resistor; and the emitter of the first transistor is grounded.

[0021] The other end of the fifth resistor is connected to one end of the sixth resistor, the collector of the second transistor, and the trigger terminal of the path control module; the other end of the sixth resistor is connected to the voltage input terminal.

[0022] The emitter of the second transistor is connected to the junction of the third resistor and the voltage input terminal;

[0023] The base of the second transistor is connected to the junction of the third resistor and the second Zener diode.

[0024] Optionally, the logic driving module further includes a second capacitor;

[0025] The second capacitor is connected in parallel across the six resistor.

[0026] Optionally, the path control module includes a PMOS transistor;

[0027] The gate of the PMOS transistor is connected to the junction of the sixth resistor and the second transistor;

[0028] The source of the PMOS transistor is connected to the voltage input terminal, and the drain of the PMOS transistor is connected to the voltage output terminal.

[0029] Secondly, this application provides an electronic device equipped with the aforementioned input overvoltage and undervoltage protection circuit.

[0030] The beneficial effects of this application are as follows: The undervoltage detection module uses a first Zener diode to identify the input voltage value for undervoltage detection, generating a trigger signal only at the first trigger terminal when the first Zener diode is broken down. The overvoltage detection module uses a second Zener diode for overvoltage detection, generating a trigger signal only at the second trigger terminal when the second Zener diode is not broken down. The logic drive module determines whether the input voltage is within the safe range based on these two trigger signals and performs corresponding protection actions. The path control module controls whether the voltage is output through the circuit according to the instructions of the logic drive module, ensuring stable and reliable voltage output.

[0031] Specifically, when the detected voltage is within the set acceptable range, the logic drive module sends a signal to turn on the path control module, thereby allowing normal voltage output; otherwise, the path control module will cut off the voltage output, effectively preventing component damage due to abnormal voltage. This design simplifies the circuit structure, reduces the need for component integration, and achieves the beneficial effects of reducing costs and PCB footprint. Attached Figure Description

[0032] Figure 1 This is a module connection diagram of the input overvoltage and undervoltage protection circuit provided in the embodiments of this application;

[0033] Figure 2 This is a circuit diagram of the input overvoltage and undervoltage protection circuit provided in the embodiments of this application;

[0034] Figure label:

[0035] R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; C1, first capacitor; C2, second capacitor; Q1, first transistor; Q2, second transistor; Q3, PMOS transistor; ZD1, first Zener diode; ZD2, second Zener diode; +Vin, voltage input terminal; +Vout, voltage output terminal. Detailed Implementation

[0036] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0037] The following will clearly and completely describe the concept, specific structure, and resulting technical effects of this application in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of this application. Obviously, the described embodiments are only a part of the embodiments of this application, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the scope of protection of this application. Furthermore, all connections / linkages involved in the patent do not simply refer to direct contact between components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. The various technical features in this application can be combined interactively without contradicting each other.

[0038] Reference Figure 1 , Figure 1 This is a module connection diagram of the input overvoltage and undervoltage protection circuit provided in an embodiment of this application. It specifically illustrates the undervoltage identification module, overvoltage identification module, logic drive module, and path control module involved in this application, which will be described in detail below:

[0039] The input terminal of the undervoltage identification module is connected to the voltage input terminal +Vin, and the output terminal of the undervoltage identification module is connected to the first trigger terminal of the logic drive module. The trigger threshold of the first trigger terminal is set through the built-in Zener diode of the undervoltage identification module.

[0040] Specifically, the undervoltage identification module samples the input voltage through the voltage input terminal +Vin, and then connects its output terminal to the first trigger terminal of the logic drive module. The undervoltage identification module has a built-in Zener diode and sets a corresponding breakdown voltage threshold. Only when the Zener diode built into the undervoltage identification module is broken down by the input voltage can it be said that the input voltage is not in an undervoltage state (i.e., the input voltage is greater than the trigger threshold of the first trigger terminal).

[0041] Furthermore, the input terminal of the overvoltage identification module is connected to the voltage input terminal +Vin, and the output terminal of the overvoltage identification module is connected to the second trigger terminal of the logic drive module. The trigger threshold of the second trigger terminal is set through the built-in Zener diode of the overvoltage identification module.

[0042] Specifically, the input terminal of the overvoltage identification module is also connected to the voltage input terminal +Vin to sample the input voltage, and its output terminal is connected to the second trigger terminal of the logic drive module. The overvoltage identification module also has a built-in Zener diode and a corresponding breakdown voltage threshold is set (this breakdown voltage threshold is greater than the breakdown voltage threshold of the Zener diode in the undervoltage identification module, forming a voltage range with it). Only when the Zener diode built into the overvoltage identification module is not broken down by the input voltage can it be said that the input voltage is not in an overvoltage state (i.e., the input voltage is less than the trigger threshold of the first trigger terminal).

[0043] Furthermore, the output terminal of the logic driving module is connected to the trigger terminal of the path control module, the input terminal of the path control module is connected to the voltage input terminal +Vin, and the output terminal of the path control module is connected to the voltage output terminal +Vout.

[0044] Specifically, the path control module connects the voltage input terminal +Vin and the voltage output terminal +Vout only when the input voltage value of the voltage input terminal +Vin is between the trigger threshold of the first trigger terminal and the trigger threshold of the second trigger terminal, forming a path from the voltage input terminal +Vin to the voltage output terminal +Vout. Under this condition, the voltage works normally from input to output.

[0045] For ease of understanding, this application provides a specific circuit implementation of the proposed solution, which can be referred to in detail. Figure 2 , Figure 2 This is a circuit diagram of the input overvoltage and undervoltage protection circuit provided in the embodiments of this application. The following is a description of the circuit. Figure 2 The specific circuit device designs for each of the above modules are described in detail below:

[0046] The undervoltage identification module includes a first resistor R1, a first Zener diode ZD1, and a second resistor R2.

[0047] One end of the first resistor R1 is connected to the voltage input terminal +Vin, and the other end is connected to the negative terminal of the Zener diode;

[0048] The positive terminal of the Zener diode is connected to one end of the second resistor R2 and the first trigger terminal of the logic drive module, and the other end of the second resistor R2 is grounded.

[0049] Specifically, when the input voltage exceeds the breakdown voltage of the first Zener diode ZD1 (this voltage can be referred to as the undervoltage point), the input voltage at the +Vin terminal is divided by the first resistor R1, breaking down the first Zener diode ZD1, and pulled down to ground by the second resistor R2. In this case, the first trigger terminal of the logic driver module will be pulled high. This high-level signal is one of the conditions used to trigger the control path of the logic driver module output to turn on the module. When the input voltage is less than or equal to the breakdown voltage of the first Zener diode ZD1, the first Zener diode ZD1 is cut off. In this case, the first trigger terminal is low and will not be triggered.

[0050] In this embodiment of the application, taking a 12V voltage input as an example, the undervoltage point can be set to 10.6V.

[0051] Furthermore, the overvoltage identification module includes a third resistor R3, a second Zener diode ZD2, and a fourth resistor R4; the breakdown voltage of the second Zener diode ZD2 is configured differently from the breakdown voltage of the first Zener diode ZD1.

[0052] One end of the third resistor R3 is connected to the voltage input terminal +Vin, and the other end is connected to the negative terminal of the second Zener diode ZD2. The positive terminal of the second Zener diode ZD2 is grounded through the fourth resistor R4.

[0053] The two ends of the third resistor R3 are connected to the second trigger terminal.

[0054] Specifically, when the input voltage is less than or equal to the breakdown voltage of the second Zener diode ZD2 (referred to as the overvoltage point), the input voltage is divided by the third resistor R3, and the voltage across the third resistor R3 is output to the second trigger terminal (i.e., the emitter and base of the second transistor Q2 shown in the diagram). Therefore, the fact that the second Zener diode ZD2 is not broken down is one of the conditions for the trigger logic drive module's output control path to conduct. The path control module will only conduct when both conditions are met simultaneously. Conversely, when the input voltage is greater than the breakdown voltage of the second Zener diode ZD2, the input voltage is divided by the third resistor R3, breaking down the second Zener diode ZD2, and pulled down to ground by the fourth resistor R4, causing the second trigger terminal to be pulled low. In this case, the input-output path will not be opened.

[0055] In this embodiment of the application, the overvoltage point can be set to 13.3V.

[0056] More specifically, the overvoltage identification module further includes a first capacitor C1;

[0057] The first capacitor C1 is connected in parallel across the three ends of the third resistor R3.

[0058] Specifically, by using capacitors in parallel, rapid on / off control of the switching transistors involved in the second trigger terminal is achieved, reducing switching losses.

[0059] Furthermore, the logic driving module includes a first transistor Q1, a fifth resistor R5, a second transistor Q2, and a sixth resistor R6;

[0060] The base of the first transistor Q1 is connected to the connection point between the first Zener diode ZD1 and the second resistor R2, the collector of the first transistor Q1 is connected to one end of the fifth resistor R5, and the emitter of the first transistor Q1 is grounded.

[0061] The other end of the fifth resistor R5 is connected to one end of the sixth resistor R6, the collector of the second transistor Q2, and the trigger terminal of the path control module. The other end of the sixth resistor R6 is connected to the voltage input terminal +Vin.

[0062] The emitter of the second transistor Q2 is connected to the junction of the third resistor R3 and the voltage input terminal +Vin.

[0063] The base of the second transistor Q2 is connected to the junction of the third resistor R3 and the second Zener diode ZD2.

[0064] Specifically, when the input voltage is between the undervoltage point and the overvoltage point (i.e., within the normal voltage range), the first Zener diode ZD1 is turned on, causing the first transistor Q1 to turn on, while the second Zener diode ZD2 is turned off, causing the second transistor Q2 to turn off. This pulls down the gate voltage of the PMOS transistor Q3, causing the PMOS transistor Q3 to turn on. Under these conditions, the voltage works normally from input to output.

[0065] More specifically, when the input voltage is below the undervoltage point, both the first Zener diode ZD1 and the second Zener diode ZD2 are turned off, and the first transistor Q1 and the second transistor Q2 are also turned off. The gate voltage of the PMOS transistor Q3 is not pulled down, causing the PMOS transistor Q3 to turn off, thus enabling undervoltage protection. When the input voltage is above the overvoltage point, both the first Zener diode ZD1 and the second Zener diode ZD2 are broken down, and both the first transistor Q1 and the second transistor Q2 are turned on. Since the second transistor Q2 is turned on, the gate voltage of the PMOS transistor Q3 is not pulled down, so the PMOS transistor Q3 is turned off, thus enabling overvoltage protection.

[0066] More specifically, the logic driving module further includes a second capacitor C2;

[0067] The second capacitor C2 is connected in parallel across the six resistor R6.

[0068] Specifically, by connecting the capacitor in parallel across the sixth resistor R6, that is, in parallel with the source and gate of the PMOS transistor Q3, it helps the switching transistor to switch on and off quickly and reduces switching losses.

[0069] Secondly, this application provides an electronic device equipped with the aforementioned input overvoltage and undervoltage protection circuit.

[0070] The above is a detailed description of the preferred embodiments of this application. However, the invention of this application is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. An input overvoltage and undervoltage protection circuit, characterized in that, include: Undervoltage identification module, overvoltage identification module, logic drive module, and path control module; The input terminal of the undervoltage identification module is connected to the voltage input terminal, and the output terminal of the undervoltage identification module is connected to the first trigger terminal of the logic drive module. The trigger threshold of the first trigger terminal is set through the built-in Zener diode of the undervoltage identification module. The input terminal of the overvoltage identification module is connected to the voltage input terminal, and the output terminal of the overvoltage identification module is connected to the second trigger terminal of the logic drive module. The trigger threshold of the second trigger terminal is set through the built-in Zener diode of the overvoltage identification module. The output terminal of the logic driving module is connected to the trigger terminal of the path control module, the input terminal of the path control module is connected to the voltage input terminal, and the output terminal of the path control module is connected to the voltage output terminal. The path control module connects the voltage input terminal and the voltage output terminal only when the input voltage value of the voltage input terminal is between the trigger threshold of the first trigger terminal and the trigger threshold of the second trigger terminal.

2. The input overvoltage and undervoltage protection circuit according to claim 1, characterized in that, The undervoltage identification module includes a first resistor, a first Zener diode, and a second resistor. One end of the first resistor is connected to the voltage input terminal, and the other end is connected to the negative terminal of the first Zener diode; The positive terminal of the first Zener diode is connected to one end of the second resistor and the first trigger terminal of the logic drive module, and the other end of the second resistor is grounded.

3. The input overvoltage and undervoltage protection circuit according to claim 2, characterized in that, The overvoltage identification module includes a third resistor, a second Zener diode, and a fourth resistor; the breakdown voltage of the second Zener diode is configured differently from that of the first Zener diode. One end of the third resistor is connected to the voltage input terminal, and the other end is connected to the negative terminal of the second Zener diode. The positive terminal of the second Zener diode is grounded through the fourth resistor. The two ends of the third resistor are connected to the second trigger terminal.

4. The input overvoltage and undervoltage protection circuit according to claim 3, characterized in that, The overvoltage identification module also includes a first capacitor; The first capacitor is connected in parallel across the three ends of the third resistor.

5. The input overvoltage and undervoltage protection circuit according to claim 3, characterized in that, The logic driving module includes a first transistor, a fifth resistor, a second transistor, and a sixth resistor; The base of the first transistor is connected to the junction of the first Zener diode and the second resistor; the collector of the first transistor is connected to one end of the fifth resistor; and the emitter of the first transistor is grounded. The other end of the fifth resistor is connected to one end of the sixth resistor, the collector of the second transistor, and the trigger terminal of the path control module; the other end of the sixth resistor is connected to the voltage input terminal. The emitter of the second transistor is connected to the junction of the third resistor and the voltage input terminal; The base of the second transistor is connected to the junction of the third resistor and the second Zener diode.

6. The input overvoltage and undervoltage protection circuit according to claim 5, characterized in that, The logic driving module also includes a second capacitor; The second capacitor is connected in parallel across the six resistor.

7. The input overvoltage and undervoltage protection circuit according to claim 5, characterized in that, The path control module includes a PMOS transistor; The gate of the PMOS transistor is connected to the junction of the sixth resistor and the second transistor; The source of the PMOS transistor is connected to the voltage input terminal, and the drain of the PMOS transistor is connected to the voltage output terminal.

8. An electronic device, characterized in that, It is equipped with an input overvoltage and undervoltage protection circuit as described in any one of claims 1-7.

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