CN214896573U

CN214896573U - Conversion circuit of liquid crystal display interface

Info

Publication number: CN214896573U
Application number: CN202121541005.7U
Authority: CN
Inventors: 骆鑫
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-07-07
Filing date: 2021-07-07
Publication date: 2021-11-26
Anticipated expiration: 2031-07-07

Abstract

The utility model discloses a conversion circuit of LCD screen interface, including power supply circuit, interface circuit and logic circuit, power supply circuit connects interface circuit and logic circuit respectively, and power supply circuit produces multichannel direct current voltage and offers interface circuit and logic circuit respectively, contains totally 8 way power and signals of 5V-VGL wherein. The logic circuit outputs 16 control signals to the interface circuit, and the control signals are used for driving the liquid crystal display to normally display, wherein the control signals comprise 16 control signals of CG 3-CSTHR. The circuit can be matched with a domestic liquid crystal screen for use, can directly replace an imported liquid crystal screen, reduces the use cost and has good display effect. Has good market value.

Description

Conversion circuit of liquid crystal display interface

Technical Field

The utility model relates to the field of electronic technology, specifically a conversion circuit of LCD screen interface.

Background

The sharp LM64183P LCD screen is a monochromatic 9.4-inch LCD screen, which is widely used for industrial computer display before, and the product is stopped in production nowadays, and the parts on the market are scarce. The current domestic liquid crystal display screen has no directly replaced model, so that the price of the imported original screen is high, and the quantity is small, thereby bringing troubles to users.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a conversion circuit of LCD screen interface to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

a conversion circuit of a liquid crystal screen interface comprises a power supply circuit, an interface circuit and a logic circuit, wherein the power supply circuit is respectively connected with the interface circuit and the logic circuit, the power supply circuit comprises a voltage doubling rectifying circuit, a chip U1 and a chip U4, the chip U1 is used for converting 5V voltage into 3.3V voltage, the chip U4 is used for converting 5V voltage into 12V voltage, the voltage doubling rectifying circuit comprises a capacitor C28, a capacitor C29, a diode D2, a diode D3, a capacitor C33 and a capacitor C35, the voltage doubling rectifying circuit is used for converting the pulse voltage of the 1 st pin of the chip U4 into two paths of positive and negative voltages, the logic circuit comprises a logic chip U10 and is used for converting the input 5V logic level into 3.3V logic level, the converted logic level is a signal in a total 11 path, the signal is UDA0-UDA1, the UDA0-UDA1 is further connected to a programmable logic chip U7, the programmable logic chip U7 is used for converting a scanning signal input into a scanning signal which is stored in a chip 8, the interface circuit is used for driving the liquid crystal screen by a control signal sent by the chip U7, the interface circuit uses two 30P PFC sockets, the model of the liquid crystal screen matched with the interface circuit is AT102TN03, and a double-row wire of the liquid crystal screen is connected with the PFC sockets in a matching mode.

As a further technical scheme of the utility model, chip U1 adopts SOT23-5 encapsulated switching power supply chip LM 2830.

As a further technical scheme of the utility model, chip U4 adopts SOT23-6 encapsulated switching power supply chip AP 3019.

As a further technical scheme of the utility model, the programmable logic chip U7 model is XC95288XL, and the encapsulation is TQFP-144.

As a further technical solution of the present invention, the logic chip U10 model is SN74LVTH 244.

As a further technical scheme of the utility model, the model of chip U8 IS IS61LV6416, and the encapsulation IS TSOP-44.

Compared with the prior art, the beneficial effects of the utility model are that: the circuit can be matched with a domestic liquid crystal screen for use, can directly replace an imported liquid crystal screen, reduces the use cost and has good display effect. Has good market value.

Drawings

Fig. 1 is an overall schematic diagram of the present invention.

Fig. 2 is a power supply circuit diagram.

Fig. 3 is a logic circuit diagram.

Fig. 4 is an interface circuit diagram.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1, embodiment 1: a conversion circuit of a liquid crystal display interface comprises a power circuit, an interface circuit and a logic circuit, wherein the power circuit is respectively connected with the interface circuit and the logic circuit.

The power circuit is shown in fig. 2, and mainly comprises two power chips, wherein the model of the U1 chip in fig. 2 is LM2830, the LM2830 is a switch power chip packaged by SOT23-5, and the circuit converts 5V voltage into 3.3V voltage.

The U4 chip is in the type of AP3019, and AP3019 is a SOT23-6 packaged switch power supply chip, and converts 5V voltage into 12V voltage in the circuit. The 12V voltage is connected to the 3 rd pin input of the U5 voltage stabilizing chip. U5 is AMS1117, and is output by U5 at pin 2, whose circuit terminal is AVDD.

In addition, the voltage doubling rectifying circuit is composed of C28, C29, D2, D3, C33 and C35, and has the function of converting the 1 st pin pulse voltage of the U4 into two positive and negative voltages, and the two positive and negative voltages are connected to a voltage stabilizing tube D4 and a voltage stabilizing tube D5 through R27 and R28 to form stable voltage. In the power circuit, the terminal VGH is a positive voltage, and the terminal VGL is a negative voltage.

The endpoint START in the power circuit is the signal controlling U4, and is connected to pin 4 of U4 through a diode D11. When the START is high, the U4 works to convert 5V into 12V output; when START is low U4 stops and the 12V output closes.

The patent protection claims, this power supply circuit has used LM2830 chip to convert 5V voltage into 3.3V voltage, has used AP3019 chip to convert 5V voltage into 12V voltage, and 12V gets stable voltage AVDD through AMS1117 voltage stabilization chip again, and AP3019 has also produced two way stable positive and negative voltages simultaneously, and the positive voltage is VGH, and the negative voltage is VGL. And the operation stop state of U5 is controlled by the START signal.

The logic circuit is shown in fig. 3, and mainly performs level conversion and data storage functions on interface data of the liquid crystal display. In fig. 3, the input logic level of the CN4 interface is 5V voltage, and the internal logic chips are all 3.3V voltage, for this reason, U9, U10 is input level conversion, model number is SN74LVTH244, and the input 5V logic level is converted into 3.3V logic level.

These converted logic levels together form 11 signals, 11 being UDA0-UDA 1. These signals are in turn connected to a programmable logic chip U7, model U7 XC95288XL packaged as TQFP-144. The U7 converts the scanning signal input into the LCD screen and stores the converted signal into the chip U8, and the model of U8 IS IS61LV6416 and TSOP-44.

Before each period of the liquid crystal screen driving signal, the U7 synchronously outputs 16 control signals, and the circuit end points are CG 4-CSTHR. In addition, U7 has a power control signal, and the circuit terminal is START.

The patent protection claims that the logic circuit uses XC95288XL programmable logic chip and IS61LV6416 memory chip as main circuit, and uses SN74LVTH244 for logic level conversion. And the interconnections between each pin of these chips are as shown in fig. 3.

The following are exemplified:

the 9 th pin of the U10 chip, the signal name of which is "UDA 0", is connected to the 131 th pin of the U7 chip;

the 16 th pin of the U9 chip, the signal name of which is "LDA 1", is connected to the 102 th pin of the U7 chip;

pin 17 of the U8 chip, with the signal name "/WE", is connected to pin 11 of the U7 chip.

The interface circuit drives the liquid crystal panel by the control signal sent from U7, as shown in fig. 4. In fig. 4, the total number of control signals is 16, the circuit terminals are CG4-CG5, and the 16 control signals are respectively connected with a buffer resistor, and the buffer resistors connect the signals to the CN1 and CN2 connectors respectively. CN1, CN2 are the connectors of the flexible flat cables of the liquid crystal screen, the model of the selected type is a 30P pin PFC socket, the model of the selected domestic liquid crystal screen is AT102TN03, and the liquid crystal screen is provided with double 30P flexible flat cables which can be matched and connected with the socket.

In embodiment 2, on the basis of embodiment 1, two 30P PFC sockets are used as an interface circuit, the model of a liquid crystal display matched with the interface circuit is AT102TN03, and a double-row cable of the liquid crystal display is connected with the PFC sockets in a matching manner.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The conversion circuit of the liquid crystal display interface comprises a power supply circuit, an interface circuit and a logic circuit, and is characterized in that the power supply circuit is respectively connected with the interface circuit and the logic circuit,

the power supply circuit comprises a voltage-multiplying rectification circuit, a chip U1 and a chip U4, wherein the chip U1 is used for converting 5V voltage into 3.3V voltage, the chip U4 is used for converting 5V voltage into 12V voltage, the voltage-multiplying rectification circuit comprises a capacitor C28, a capacitor C29, a diode D2, a diode D3, a capacitor C33 and a capacitor C35, and the voltage-multiplying rectification circuit is used for converting the 1 st pin pulse voltage of the chip U4 into two paths of positive and negative voltages;

the logic circuit comprises a logic chip U10, wherein the logic chip U10 is used for converting an input 5V logic level into a 3.3V logic level, the converted logic level comprises 11 paths of signals, the 11 paths of signals are UDA0-UDA1, the UDA0-UDA1 are connected to a programmable logic chip U7, and the programmable logic chip U7 converts a scanning signal input into a liquid crystal screen and stores the converted scanning signal into a chip U8;

the interface circuit is used for driving the liquid crystal screen by a control signal sent by the chip U7, the interface circuit uses two 30P PFC sockets, the model of the liquid crystal screen connected with the interface circuit is AT102TN03, and a double-row cable of the liquid crystal screen is connected with the PFC sockets in a matching mode.

2. The converting circuit of a liquid crystal display interface of claim 1, wherein the chip U1 is a switching power supply chip LM2830 packaged by SOT 23-5.

3. The conversion circuit of a liquid crystal screen interface of claim 1, wherein the chip U4 is a switch power supply chip AP3019 packaged by SOT 23-6.

4. The conversion circuit of a liquid crystal screen interface of claim 1, wherein the programmable logic chip U7 model is XC95288XL packaged as TQFP-144.

5. The conversion circuit of a liquid crystal screen interface according to claim 1, wherein the liquid crystal screen model connected by the interface circuit is AT102TN 03.

6. The converting circuit of a liquid crystal screen interface of claim 1, wherein the model of the chip U8 IS IS61LV6416, and the package IS TSOP-44.