Voltage conversion circuit, device and system of serial port screen

Abstract

The utility model discloses a serial port screen voltage conversion circuit, device and system, the serial port screen voltage conversion circuit comprises a static protector, a serial port screen interface, an impedance circuit, a first MOS tube, a second MOS tube and a power supply interface unit, the static protector is connected with the impedance circuit and the serial port screen interface, the grid electrode of the first MOS tube is connected with the grid electrode of the second MOS tube, and the impedance circuit is connected with the first MOS tube. A drain electrode of the first MOS tube and a drain electrode of the second MOS tube are respectively connected with different pins of the serial port screen interface, one end of the impedance circuit and a grid electrode of the first MOS tube are connected with a first voltage, the power supply interface unit is connected with the serial port screen interface, a second voltage is accessed to the power supply interface unit, and the second voltage is higher than the first voltage. The first MOS tube and the second MOS tube are both used for converting the second voltage of the serial port screen into the first voltage. The serial port screen voltage is effectively converted through the first MOS tube and the second MOS tube, and it is ensured that the safety voltage requirement of the main control end is met.

Description

Technical Field

[0001] This application relates to the technical field of serial port displays, and specifically, to a voltage conversion circuit, device, and system for a serial port display. Background Art

[0002] Serial port displays, that is, serial interface displays, are usually used in the human-machine interface (HMI) of industrial control systems or for some simple data display. They are connected to the main controller (such as a single-chip microcomputer, PLC, or computer) through a serial communication interface. The serial port signal voltage of some serial port displays is 3.3V, and the serial port signal voltage of some serial port displays is 5V. However, the main control end of the main board only supports a 3.3V safe voltage. If a 5V serial port display is connected, there is a risk of burning out the main control. Therefore, it is necessary to propose a circuit applicable to 3.3V and 5V. Summary of the Utility Model

[0003] The purpose of this application is to provide a voltage conversion circuit, device, and system for a serial port display to solve the problem that the voltage between the existing main control end of the main board and the serial port display is inconsistent, resulting in burning out the main control of the main board.

[0004] To solve the above problems, this application adopts the following technical solutions to achieve:

[0005] In the first aspect of this application, a voltage conversion circuit for a serial port display is provided. The voltage conversion circuit for the serial port display includes: an electrostatic protector, a serial port display interface, an impedance circuit, a first MOS transistor, a second MOS transistor, and a power interface unit. The electrostatic protector is respectively connected to the impedance circuit and the serial port display interface. The gates of the first MOS transistor and the second MOS transistor are connected. The drains of the first MOS transistor and the second MOS transistor are respectively connected to different pins of the serial port display interface. One end of the impedance circuit and the gate of the first MOS transistor are both connected to a first voltage. The power interface unit is connected to the serial port display interface, and the power interface unit accesses a second voltage, where the second voltage is higher than the first voltage. The first MOS transistor and the second MOS transistor are both used to convert the second voltage of the serial port display to the first voltage.

[0006] By adopting an electrostatic protector, it is possible to prevent device damage caused by electrostatic accumulation and improve the anti-interference ability of the entire system. Using MOS transistors as switching elements can effectively convert the serial port display voltage to ensure that the safety voltage requirements of the main control end are met.

[0007] Further, the impedance circuit includes a first resistor and a second resistor. One end of the first resistor and one end of the second resistor are both connected to the first voltage, and the other end of the first resistor and the other end of the second resistor are connected to different pins of the serial port display interface.

[0008] Through the first resistor and the second resistor, it is possible to adapt to serial screens with different voltages, ensuring the stability and accuracy of voltage conversion, as well as ensuring voltage safety and signal stability, and reducing the potential damage to the main control end caused by overvoltage.

[0009] Furthermore, the resistance values of the first resistor and the second resistor are the same.

[0010] By using two resistors with the same resistance value, it is possible to achieve balanced distribution of voltage and ensure the stability of the voltages of each pin of the serial screen interface.

[0011] Furthermore, the voltage conversion circuit of the serial screen includes a third resistor, and both ends of the third resistor are respectively connected to the source electrode and the drain electrode of the first MOS transistor.

[0012] Through the third resistor, the voltage between the source electrode and the drain electrode of the first MOS transistor can be controlled to ensure the smoothness and controllability of the voltage conversion process.

[0013] Furthermore, the voltage conversion circuit of the serial screen includes a fourth resistor, and both ends of the fourth resistor are respectively connected to the source electrode and the drain electrode of the second MOS transistor.

[0014] Through the fourth resistor, the voltage between the source electrode and the drain electrode of the second MOS transistor can be controlled to ensure the smoothness and controllability of the voltage conversion process.

[0015] Furthermore, the voltage conversion circuit of the serial screen includes a fifth resistor, one end of the fifth resistor is grounded, and the other end of the fifth resistor is connected to the VCC port of the power interface unit.

[0016] By using the fifth resistor and grounding one end of it, a stable voltage reference can be provided to ensure the stable operation of the voltage conversion circuit. Grounding the fifth resistor helps protect the circuit and prevent circuit damage caused by voltage fluctuations.

[0017] Furthermore, the voltage conversion circuit of the serial screen includes a first capacitor and a second capacitor. One end of the first capacitor and one end of the second capacitor are both grounded, and the other end of the first capacitor and the other end of the second capacitor are both connected to the VCC port of the power interface unit.

[0018] Through the first capacitor and the second capacitor, the current in the voltage conversion circuit can be filtered to reduce voltage fluctuations and noise and ensure voltage stability.

[0019] Furthermore, the capacitance values of the first capacitor and the second capacitor are different.

[0020] By using two capacitors with different capacitances, filtering can be performed according to different frequency characteristics, effectively removing noise and fluctuations in different frequency bands, thereby optimizing the filtering effect.

[0021] The present application also provides a voltage conversion device for a serial port screen, including a housing having a receiving cavity formed therein, and the voltage conversion circuit for the serial port screen according to any one of the above, disposed within the housing.

[0022] The present application also provides a voltage conversion system for a serial port screen, and the voltage conversion system for the serial port screen includes the above-mentioned voltage conversion device for the serial port screen.

[0023] Compared with the prior art, the beneficial effects of the present application are as follows: Since the gate of the first MOS transistor is connected to the gate of the second MOS transistor, the drains of the first MOS transistor and the second MOS transistor are respectively connected to different pins of the serial port screen interface, one end of the impedance circuit and the gate of the first MOS transistor are both connected to a first voltage, and through the first MOS transistor and the second MOS transistor, the voltage of the serial port screen is effectively converted to ensure that the safety voltage requirements of the master control end are met. Description of the Drawings

[0024] Figure 1 is a schematic diagram of a voltage conversion circuit for a serial port screen provided by an embodiment of the present application; and

[0025] Figure 2 is a schematic diagram of a power interface unit provided by an embodiment of the present application.

[0026] Description of the Reference Numerals:

[0027] 100, electrostatic protector; 200, serial port screen interface; 300, impedance circuit; 400, first MOS transistor; 500, second MOS transistor; 600, power interface unit; 310, first resistor; 320, second resistor; 700, third resistor; 800, fourth resistor; 900, fifth resistor; 1000, first capacitor; 1100, second capacitor. Detailed Embodiments

[0028] The following will describe in detail the specific embodiments of the present application with reference to the drawings.

[0029] It should be noted that, without conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other. The detailed description in the specific embodiments should be understood as an explanatory illustration of the purpose of the present application and should not be regarded as an improper limitation of the present application.

[0030] It should be understood that the orientation or positional relationship is based on the orientation or positional relationship shown in the drawings. These orientation terms are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present application.

[0031] Figure 1 FIG. 4 is a schematic diagram of a voltage conversion circuit of a serial port screen provided by an embodiment of the present application, and FIG. 2 is a schematic diagram of a power interface unit provided by an embodiment of the present application. As Figure 1 and Figure 2 shown, an embodiment of the present application provides a voltage conversion circuit for a serial port screen, including: an electrostatic protector 100, a serial port screen interface 200, an impedance circuit 300, a first MOS transistor 400, a second MOS transistor 500, and a power interface unit 600. The electrostatic protector 100 is respectively connected to the impedance circuit 300 and the serial port screen interface 200. The gates of the first MOS transistor 400 and the second MOS transistor 500 are connected. The drains of the first MOS transistor 400 and the second MOS transistor 500 are respectively connected to different pins of the serial port screen interface 200. One end of the impedance circuit 300 and the gate of the first MOS transistor 400 are both connected to a first voltage. The power interface unit 600 is connected to the serial port screen interface 200, and the power interface unit 600 accesses a second voltage, where the second voltage is higher than the first voltage. The first MOS transistor 400 and the second MOS transistor 500 are both used to convert the second voltage of the serial port screen to the first voltage.

[0032] Specifically, connect the electrostatic protector 100 to the impedance circuit 300 and the serial port screen interface 200 to ensure the safety of the circuit and prevent electrostatic damage. Connect a first voltage to one end of the impedance circuit 300 and the gate of the first MOS transistor 400 at the other end to provide appropriate impedance matching and signal transmission. Connect the drains of the first MOS transistor 400 and the second MOS transistor 500 to different pins of the serial port screen interface 200 respectively, and at the same time ensure that the gates of the first MOS transistor 400 and the second MOS transistor 500 are connected. Connect the power interface unit 600 to the serial port screen interface 200 and access a second voltage, and the second voltage should be higher than the first voltage. The first MOS transistor 400 and the second MOS transistor 500 work together to convert the second voltage of the serial port screen to the first voltage. For example, for example, the first voltage is 3.3V and the second voltage is 5V. Through the combined action of the first MOS transistor 400 and the second MOS transistor 500, the requirement that the main control end of the motherboard only supports a 3.3V safe voltage is met.

[0033] By adopting the electrostatic protector 100, equipment damage caused by electrostatic accumulation is prevented, and the anti-interference ability of the entire system is improved. Using the first MOS transistor 400 and the second MOS transistor 500 as switching elements, the serial screen voltage can be effectively converted to ensure that the safety voltage requirements of the main control end are met.

[0034] In some embodiments, the impedance circuit 300 includes a first resistor 310 and a second resistor 320. One end of the first resistor 310 and one end of the second resistor 320 are both connected to the first voltage, and the other end of the first resistor 310 and the other end of the second resistor 320 are connected to different pins of the serial screen interface 200.

[0035] Specifically, the first resistor 310 and the second resistor 320 are arranged in the impedance circuit 300. One end of the first resistor 310 and one end of the second resistor 320 are both connected to the first voltage (3.3V) to ensure the stability of the circuit and proper signal transmission. The other end of the first resistor 310 and the other end of the second resistor 320 are connected to different pins of the serial screen interface 200 to provide proper impedance matching and signal transmission. After the circuit is built, tests and verifications are carried out to ensure that the impedance circuit 300 can work properly and can adapt the signal voltage of the serial screen to the 3.3V safety voltage supported by the main board main control end.

[0036] According to the specific serial screen signal voltage and the supported voltage of the main board main control end, the values of the first resistor 310 and the second resistor 320 are adjusted to achieve accurate voltage conversion and adaptation. In particular, the resistance values of the first resistor 310 and the second resistor 320 are the same. By using two resistors with the same resistance value, balanced distribution of voltage can be achieved to ensure the stability of the voltages of each pin of the serial screen interface.

[0037] Through the first resistor 310 and the second resistor 320, serial screens with different voltages can be adapted, ensuring the stability and accuracy of voltage conversion, as well as voltage safety and signal stability, and reducing the potential damage to the main control end caused by overvoltage.

[0038] In some embodiments, the voltage conversion circuit of the serial screen includes a third resistor 700. Two ends of the third resistor 700 are respectively connected to the source and drain of the first MOS transistor 400.

[0039] Specifically, two ends of the third resistor 700 are respectively connected to the source and drain of the first MOS transistor 400. This connection method helps to control the current flow and protects the circuit from being affected by too high or too low voltages. After the circuit is built, tests and verifications are carried out to ensure that the third resistor 700 can work properly and will not cause damage to other circuit components. According to the specific voltage conversion requirements, the resistance value of the third resistor 700 is adjusted to achieve accurate voltage conversion and adaptation.

[0040] Through the third resistor 700, the voltage between the source and drain of the first MOS transistor 400 can be controlled to ensure the smooth and controllable voltage conversion process.

[0041] In some embodiments, the voltage conversion circuit of the serial port screen includes a fourth resistor 800, and both ends of the fourth resistor 800 are respectively connected to the source and drain of the second MOS transistor 500.

[0042] Specifically, both ends of the fourth resistor 800 are respectively connected to the source and drain of the second MOS transistor 500. This connection method helps to control the current flow and protect the circuit from excessive or too low voltages. After the circuit is built, perform tests and verifications to ensure that the fourth resistor 800 can work properly and will not cause damage to other circuit components. According to the specific voltage conversion requirements, adjust the resistance value of the fourth resistor 800 to achieve accurate voltage conversion and adaptation.

[0043] Through the fourth resistor 800, the voltage between the source and drain of the second MOS transistor 500 can be controlled to ensure the smooth and controllable voltage conversion process.

[0044] In some embodiments, the voltage conversion circuit of the serial port screen includes a fifth resistor 900. One end of the fifth resistor 900 is grounded, and the other end of the fifth resistor 900 is connected to the VCC port of the power interface unit 600.

[0045] Specifically, first prepare the fifth resistor 900 and the power interface unit 600 to ensure that they can be used to connect other parts of the circuit. Ground one end of the fifth resistor 900 to ensure the safety and stability of the circuit. Connect the other end to the VCC port of the power interface unit 600 to provide an appropriate power supply voltage. Connect the power interface unit 600 to the circuit and ensure that its VCC port accesses the second voltage, and the second voltage should be higher than the first voltage. According to the specific voltage conversion requirements, adjust the resistance value of the fifth resistor 900 to achieve accurate voltage conversion and adaptation.

[0046] By the fifth resistor 900 and grounding one of its ends, a stable voltage reference can be provided to ensure the stable operation of the voltage conversion circuit. Grounding the fifth resistor 900 helps to protect the circuit and prevent circuit damage caused by voltage fluctuations.

[0047] In some embodiments, the voltage conversion circuit of the serial port screen includes a first capacitor 1000 and a second capacitor 1100. One end of the first capacitor 1000 and one end of the second capacitor 1100 are both grounded, and the other end of the first capacitor 1000 and the other end of the second capacitor 1100 are both connected to the VCC port of the power interface unit 600.

[0048] Specifically, one end of the first capacitor 1000 and one end of the second capacitor 1100 are both grounded to ensure the safety and stability of the circuit, and the other ends are both connected to the VCC port of the power interface unit 600 to provide an appropriate power supply voltage. The power interface unit 600 is connected to the circuit, and it is ensured that its VCC port is connected to a second voltage, and the second voltage should be higher than the first voltage. After the circuit is built, tests and verifications are carried out to ensure that the first capacitor 1000 and the second capacitor 1100 can work properly, and the stability of the first capacitor 1000 and the second capacitor 1100 under different working conditions, such as temperature changes, voltage fluctuations, etc., is evaluated to ensure the long-term reliability of the circuit.

[0049] Through the first capacitor 1000 and the second capacitor 1100, the current in the voltage conversion circuit can be filtered, voltage fluctuations and noise can be reduced, and the stability of the voltage can be ensured.

[0050] This application also provides a voltage conversion device for a serial port screen, including a housing with a receiving cavity formed therein, and the voltage conversion circuit for a serial port screen according to any one of the above, which is disposed in the housing.

[0051] This application also provides a voltage conversion system for a serial port screen, and the voltage conversion system for a serial port screen includes the above-mentioned voltage conversion device for a serial port screen.

[0052] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions required to be protected by the present application.

Claims

1. A voltage conversion circuit for a serial port screen, characterized in that: The voltage conversion circuit of the serial port screen includes: an electrostatic protector, a serial port screen interface, an impedance circuit, a first MOS tube, a second MOS tube and a power interface unit, the electrostatic protector is respectively connected to the impedance circuit and the serial port screen interface, the gate of the first MOS tube is connected to the gate of the second MOS tube, the drain of the first MOS tube and the drain of the second MOS tube are respectively connected to different pins of the serial port screen interface, one end of the impedance circuit and the gate of the first MOS tube are both connected to a first voltage, the power interface unit is connected to the serial port screen interface, and the power interface unit is connected to a second voltage, wherein the second voltage is higher than the first voltage, and the first MOS tube and the second MOS tube are both used to convert the second voltage of the serial port screen to the first voltage.

2. The voltage conversion circuit of a serial port screen according to claim 1, characterized in that: The impedance circuit includes a first resistor and a second resistor, one end of the first resistor and one end of the second resistor are both connected to the first voltage, and the other end of the first resistor and the other end of the second resistor are connected to different pins of the serial port screen interface.

3. The voltage conversion circuit of a serial port screen according to claim 2, characterized in that: The first resistor and the second resistor have the same resistance value.

4. The voltage conversion circuit of a serial port screen according to claim 1, characterized in that: The voltage conversion circuit of the serial port screen includes a third resistor, and two ends of the third resistor are respectively connected to the source and drain of the first MOS tube.

5. The voltage conversion circuit of a serial port screen according to claim 1, characterized in that: The voltage conversion circuit of the serial port screen includes a fourth resistor, and two ends of the fourth resistor are respectively connected to the source and drain of the second MOS tube.

6. The voltage conversion circuit of a serial port screen according to claim 1, characterized in that: The voltage conversion circuit of the serial port screen includes a fifth resistor, one end of the fifth resistor is grounded, and the other end of the fifth resistor is connected to the VCC port of the power interface unit.

7. The voltage conversion circuit of a serial port screen according to claim 6, characterized in that: The voltage conversion circuit of the serial port screen includes a first capacitor and a second capacitor, one end of the first capacitor and one end of the second capacitor are both grounded, and the other end of the first capacitor and the other end of the second capacitor are both connected to the VCC port of the power interface unit.

8. The voltage conversion circuit of a serial port screen according to claim 7, characterized in that: The first capacitor and the second capacitor have different capacitances.

9. A voltage conversion device for a serial port screen, characterized in that: A shell having a receiving cavity formed therein, and a voltage conversion circuit of the serial port screen according to any one of claims 1 to 8 are arranged in the shell.

10. A voltage conversion system for a serial port screen, characterized in that: The voltage conversion system of the serial port screen includes the voltage conversion device of the serial port screen as described in claim 9.

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