CN208190249U - A kind of LCD protection circuit - Google Patents

Abstract

The utility model discloses a kind of LCD, and circuit, including mainboard MCU, LCD display module and protection circuit, the mainboard MCU to be protected to be equipped with several signal output interfaces；The LCD display module is equipped with LCD and shows driving interface；The protection circuit includes electrostatic protection element ESD1~electrostatic protection element ESD4, resistance R1~resistance R4, capacitor C1~capacitor C4.This LCD protects circuit, avoids cmos circuit from being played a very good protection by electrostatic breakdown to component by electrostatic protection element ESD1~electrostatic protection element ESD4 of connection；Resistance R1 constitutes filter circuit with C4 after capacitor C1, resistance R2 and capacitor C2, resistance R3 and capacitor C3 and resistance R4 and capacitor; the vibration frequency signal for avoiding electrostatic from generating impacts the work of component; co-mode coil La and co-mode coil Lb is when external disturbance leads to electric leakage beyond electrical boundaries or deposition dust; it will be released in the form of electric arc, to protect LCD mould group；Overall work is stablized, good to component protecting effect.

Description

A kind of LCD protection circuit

Technical field

The utility model relates to LCD display device technical field, specially a kind of LCD protects circuit.

Background technique

LCD module is LCM (LCD Module) i.e. LCD display module, refers to and is integrated together glass and LCD driver LCD show product, the LCD that he provides one standard of user shows driving interface (having 4,8, the different type such as VGA), User operate control LCD always according to interface requirement and correctly shows.

Control, driving circuit in module are the cmos circuits of low pressure, micro energy lose, easily by electrostatic breakdown, usual LCD mould The data transmission rate of block is less than 20Mbps, so the protective device less than 40pf can be used, therefore proposes a kind of LCD protection electricity Road.

Utility model content

The purpose of this utility model is to provide a kind of LCD to protect circuit, has the operation is stable, to component protecting effect Good advantage solves the problems, such as that the cmos circuit in LCD display module in the prior art is easily damaged by electrostatic breakdown.

To achieve the above object, the utility model provides the following technical solutions: a kind of LCD protection circuit, including mainboard MCU, LCD display module and protection circuit, the mainboard MCU are equipped with several signal output interfaces, several signal output interfaces Including No. 1 signal output interface, No. 2 signal output interfaces, No. 3 signal output interfaces, No. 4 signal output interfaces and No. 5 letters Number output terminal, between No. 1 signal output interface and No. 2 signal output interfaces and is connected to co-mode coil La, No. 3 signal output interfaces Between No. 4 signal output interfaces and it is connected to co-mode coil Lb；The LCD display module is equipped with LCD and shows driving interface, LCD Show that driving interface includes driving display interface terminal D1, display driving interface terminal D2, display driving interface terminal D3, display Driving interface terminal D4 and signal ground terminal；The protection circuit includes electrostatic protection element ESD1~electrostatic protection element ESD4, resistance R1~resistance R4, capacitor C1~capacitor C4, No. 1 signal output interface, No. 2 signal output interfaces, No. 3 signals are defeated Outgoing interface and No. 4 signal output interface difference series resistor R1, resistance R2, resistance R3, resistance R4 and display driving interface terminal D1, display driving interface terminal D2, display driving interface terminal D3 and display driving interface terminal D4 electrical connection, No. 5 signals are defeated Terminal connects signal ground terminal, the input end grounding of signal ground terminal out；The both ends shunt-wound capacitance C1 of the resistance R1, resistance The both ends shunt-wound capacitance C4 of the both ends shunt-wound capacitance C3 of the both ends shunt-wound capacitance C2 of R2, resistance R3, resistance R2；The resistance R1's Input termination electrostatic protection element ESD1 ground connection, the input termination electrostatic protection element ESD2 ground connection of resistance R2, resistance R3's is defeated Enter to terminate electrostatic protection element ESD3 ground connection, the input termination electrostatic protection element ESD4 ground connection of resistance R4.

Preferably, the LCD shows driving interface using 4,8, the different types such as VGA.

Preferably, the model ESD0402 series of the electrostatic protection element ESD1~electrostatic protection element ESD4.

Preferably, the transmission rate of the LCD display module is less than 20Mbps.

Preferably, the inductance size of the co-mode coil La and co-mode coil Lb is 1mH.

Compared with prior art, the beneficial effects of the utility model are as follows:

This LCD protects circuit, can avoid CMOS by electrostatic protection element ESD1~electrostatic protection element ESD4 of connection Circuit plays a very good protection to component by electrostatic breakdown；Resistance R1 and capacitor C1, resistance R2 and capacitor C2, electricity C4 constitutes filter circuit after hindering R3 and capacitor C3 and resistance R4 and capacitor, reduces the alternating component in the DC voltage of pulsation, Retain its flip-flop, reduces the ripple coefficient of voltage of output, waveform becomes the vibration frequency for steadily avoiding electrostatic from generating Signal impacts the work of component, and co-mode coil La and co-mode coil Lb beyond electrical boundaries or sink in external disturbance When dust stratification dirt leads to electric leakage, it will released in the form of electric arc, to protect LCD mould group；Overall work is stablized, and protects to component It is good to protect effect.

Detailed description of the invention

Fig. 1 is the protection circuit diagram of the utility model.

In figure: 1 mainboard MCU, 2LCD display module, 3 protection circuits.

Specific embodiment

The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without making creative work Every other embodiment obtained, fall within the protection scope of the utility model.

Referring to Fig. 1, a kind of LCD protects circuit, including mainboard MCU1, LCD display module 2 and protection circuit 3, mainboard MCU1 is equipped with several signal output interfaces, and several signal output interfaces connect including No. 1 signal output interface, No. 2 signals outputs Mouth, No. 3 signal output interfaces, No. 4 signal output interfaces and No. 5 signal output terminals, No. 1 signal output interface and No. 2 letters Between number output interface and it is connected to co-mode coil La, between No. 3 signal output interfaces and No. 4 signal output interfaces and is connected to co-mode coil The inductance size of Lb, co-mode coil La and co-mode coil Lb are 1mH；The transmission rate of LCD display module 2 is less than 20Mbps, can It is used in the protective device less than 40pf, LCD display module 2 is equipped with LCD and shows driving interface, and LCD shows that driving interface is adopted With 4,8, the different types such as VGA, LCD shows that driving interface includes display driving interface terminal D1, display driving interface end Sub- D2, display driving interface terminal D3, display driving interface terminal D4 and signal ground terminal；Circuit 3 is protected to protect including electrostatic Protection element ESD1~electrostatic protection element ESD4, resistance R1~resistance R4, capacitor C1~capacitor C4, wherein electrostatic protection element ESD1~electrostatic protection element ESD4 model ESD0402 series, capacitor are respectively less than 40pf, suitable for LCD protection electricity Road, No. 1 signal output interface, No. 2 signal output interfaces, No. 3 signal output interfaces and No. 4 signal output interfaces concatenate electricity respectively Hinder R1, resistance R2, resistance R3, resistance R4 and display driving interface terminal D1, display driving interface terminal D2, display driving interface Terminal D3 and display driving interface terminal D4 electrical connection, No. 5 signal output terminals connect signal ground terminal, signal ground terminal Input end grounding；The both ends shunt-wound capacitance C2 of the both ends shunt-wound capacitance C1 of resistance R1, resistance R2, the both ends shunt-wound capacitance of resistance R3 The both ends shunt-wound capacitance C4 of C3, resistance R2；The input termination electrostatic protection element ESD1 ground connection of resistance R1, the input terminal of resistance R2 Connect electrostatic protection element ESD2 ground connection, the input termination electrostatic protection element ESD3 ground connection of resistance R3, the input termination of resistance R4 Electrostatic protection element ESD4 ground connection.

The LCD protects circuit, by terminating electrostatic protection element ESD1 ground connection in the input of resistance R1 respectively, resistance R2's Input termination electrostatic protection element ESD2 ground connection, the input termination electrostatic protection element ESD3 ground connection of resistance R3, resistance R4's is defeated Enter to terminate electrostatic protection element ESD4 ground connection, when due to electrostatic contact to electronic component or equipment, electrostatic will be by being connect Touching object discharges over the ground, and discharge time is extremely short, and generated discharge current is very big, it is easy to component is damaged, and LCD shows mould Control, driving circuit in group 2 are the cmos circuits of low pressure, micro energy lose, and easily by electrostatic breakdown, and LCD display module 2 makes Used time often in contact with arrive electrostatic, by electrostatic protection element ESD1~electrostatic protection element ESD4 of connection avoid cmos circuit by To electrostatic breakdown, play a very good protection to component；Resistance R1 and capacitor C1, resistance R2 and capacitor C2, resistance R3 and Capacitor C3 and resistance R4 constitutes filter circuit with C4 after capacitor, reduces the alternating component in the DC voltage of pulsation, retains it Flip-flop reduces the ripple coefficient of voltage of output, and waveform becomes the signal pair for the vibration frequency for steadily avoiding electrostatic from generating The work of component impacts, by meeting co-mode coil La and co-mode coil Lb, when external disturbance exceed electrical boundaries, or Deposition dust causes to leak electricity, it will is released in the form of electric arc, the length of electric arc is between 2.54mm+-0.5mm, to protect LCD mould group.

In summary: this LCD protects circuit, and the control, driving circuit in LCD display module 2 are low pressure, micro energy lose Cmos circuit, easily by electrostatic breakdown, and LCD display module 2 is protected when in use often in contact with electrostatic is arrived by the electrostatic of connection Protection element ESD1~electrostatic protection element ESD4 avoids cmos circuit by electrostatic breakdown, plays protection well to component and makees With；Resistance R1 constitutes filtered electrical with C4 after capacitor C1, resistance R2 and capacitor C2, resistance R3 and capacitor C3 and resistance R4 and capacitor Road reduces the alternating component in the DC voltage of pulsation, retains its flip-flop, reduces the ripple coefficient of voltage of output, wave The signal that deformation obtains the vibration frequency for steadily avoiding electrostatic from generating impacts the work of component；Co-mode coil La and altogether Loft circle Lb is when external disturbance leads to electric leakage beyond electrical boundaries or deposition dust, it will it is released in the form of electric arc, from And protect LCD mould group；Overall work is stablized, good to component protecting effect.

While there has been shown and described that the embodiments of the present invention, for the ordinary skill in the art, It is understood that these embodiments can be carried out with a variety of variations in the case where not departing from the principles of the present invention and spirit, repaired Change, replacement and variant, the scope of the utility model is defined by the appended claims and the equivalents thereof.

Claims (5)

1. a kind of LCD protects circuit, including mainboard MCU (1), LCD display module (2) and protection circuit (3), it is characterised in that: The mainboard MCU (1) is equipped with several signal output interfaces, and several signal output interfaces include No. 1 signal output interface, No. 2 Signal output interface, No. 3 signal output interfaces, No. 4 signal output interfaces and No. 5 signal output terminals, No. 1 signal output connect Between mouthful No. 2 signal output interfaces and it is connected to co-mode coil La, between No. 3 signal output interfaces and No. 4 signal output interfaces and is connect There is co-mode coil Lb；The LCD display module (2) is equipped with LCD and shows driving interface, and LCD shows that driving interface includes display Driving interface terminal D1, display driving interface terminal D2, display driving interface terminal D3, display driving interface terminal D4 and signal Ground terminal；The protection circuit (3) includes electrostatic protection element ESD1~electrostatic protection element ESD4, resistance R1~resistance R4, capacitor C1~capacitor C4, No. 1 signal output interface, No. 2 signal output interfaces, No. 3 signal output interfaces and No. 4 signals are defeated Outgoing interface distinguishes series resistor R1, resistance R2, resistance R3, resistance R4 and display driving interface terminal D1, display driving interface end Sub- D2, display driving interface terminal D3 and display driving interface terminal D4 electrical connection, No. 5 signal output terminals connect signal ground end Son, the input end grounding of signal ground terminal；The both ends shunt-wound capacitance C1 of the resistance R1, the both ends shunt-wound capacitance of resistance R2 The both ends shunt-wound capacitance C4 of the both ends shunt-wound capacitance C3 of C2, resistance R3, resistance R2；The input of the resistance R1 terminates electrostatic protection Element ESD1 ground connection, the input termination electrostatic protection element ESD2 ground connection of resistance R2, the input termination electrostatic protection member of resistance R3 Part ESD3 ground connection, the input termination electrostatic protection element ESD4 ground connection of resistance R4.

2. a kind of LCD according to claim 1 protects circuit, it is characterised in that: the LCD shows that driving interface uses 4 Position, 8, the different types such as VGA.

3. a kind of LCD according to claim 1 protects circuit, it is characterised in that: the electrostatic protection element ESD1~quiet The model ESD0402 series of electric protection element ESD4.

4. a kind of LCD according to claim 1 protects circuit, it is characterised in that: the transmission of the LCD display module (2) Rate is less than 20Mbps.

5. a kind of LCD according to claim 1 protects circuit, it is characterised in that: the co-mode coil La and co-mode coil The inductance size of Lb is 1mH.