What Are The Design Principles Of LCD Module Screen TV?

Nowadays, smart products are very popular with everyone. Many manufacturers will come to this industry. Here, the editor will give you a good description of the LCD module screen TV. Its structure mainly includes: liquid crystal display module, power supply module, drive module and button module. Generally, the LCD module has been tested for electromagnetic compatibility (EMC) by the manufacturer before production. EMC is an inevitable and important issue in LCD TV design. If the EMC design is not good, it will lead to weak interference tolerance, water ripples and stroboscopic problems during the TV broadcast, and in serious cases, it will be unable to watch. The following mainly briefly describes the design of the key parts of EMC:

1. Driver board design

The most important means to overcome electromagnetic interference is to ground. The main driving board of LCD module screen TV mainly includes: analog signal part, high-speed digital circuit part, noise source DC-DC power supply part. On the LCD TV drive board, the ground of the power supply part (DC-DC) is mainly separated from the ground of other parts such as decoding and main chip processing, so as to reduce the interference of the power supply on the image display and TV sound. DC-DC power supply part and ground: On the printed circuit board, the power line and the ground line are the most important. Let the analog circuit and the digital circuit have their own power and ground paths respectively.

2. Whole machine design

Utilization of shielding cover: Generally, the LCD module, main control board and power supply part need shielding cover. The main frequency of the main chip is the main cause of electromagnetic interference. Frequency harmonics of the main frequency are most likely to cause electromagnetic interference. In the EMC experiment, the electromagnetic interference of the frequency harmonics of the main frequency is very large. Certain shielding measures should be added to the main chip during design. The main shielding measure is to add a metal shield on the digital board. Adding a shielding cover is the most effective way to resist electromagnetic interference.

3. Power module design

The power supply part of LCD TV adopts switching power supply. The reason for the electromagnetic interference problem caused by the switching power supply is very complicated. The two main functions of the power supply are to drive the backlight of the LCD screen and provide DC power for other modules (including drive modules and key modules). The design of the power module directly affects the entire system. If the design is not good, it will cause large water ripples on the TV, and in severe cases, it will cause the TV to be unusable. At the same time, it will seriously affect the normal use of other nearby equipment.