Types and Selection of TFT LCD Module Interfaces

TFT LCD display module consists of an FTF LCD panel, one or more COG (chip on glass) or COB (chip on board) driver ICs, a backlight, and an interface. There are currently several TFT display interface technologies, and the selection of the appropriate interface depends on the specific terminal product. In the past few years, different types of TFT interfaces have been designed for various display screens of different sizes, including LVDS, (low voltage difference signal) parallel, SPI (serial peripheral interface) RGB, and so on. The following is an introduction to various interfaces, which can help you better understand the center position of TFT LCD displays.

TFT LCD Interface - Technical Section

Usually, the interface of TFT is mainly determined by the specific TFT panel size and resolution.

SPI LCD interface: The serial peripheral interface allows for serial (one bit at a time) data exchange between two devices. Compared to parallel, one advantage of SPI is its simple wiring. SPI can also connect longer cables because the

Less interaction or crosstalk. The disadvantage of SPI is that you cannot read from the TFT LCD display, can only write, and the speed is very slow. That's why we usually see small-sized TFT LCD screens with SPI interfaces.

MCU parallel interface: Many modern MCUs have built-in LCD controller functions, and there are two types, 6800 and 8080. Typically, MCU/parallel interfaces consist of data signals (4/8/9/16 bits) and control signals. The MCU interface is simple,But RAM needs to be displayed.

RGB interface: The RGB interface is a special parallel interface that does not require the display of RAM. The MCU directly updates the TFT screen, sends red, green, and blue pixel data (16/18/24 bits) and time signals. The RBG interface can communicate with the TFT LCD. High speed communication, but it requires more data lines and more complex control.

LVDS interface: Low voltage differential signal is a special data signal standard. LVDS interface devices can communicate at high speed through inexpensive twisted pair copper covered cables, which can reduce electromagnetic interference and serial interference issues, The transmission device can be located further away from the TFT LCD display screen.

UART/RS232/RS485: Intelligent LCD display modules use these serial interfaces, and the Universal Asynchronous Receiver Transmitter (UART) is the circuit area responsible for serial communication. Essentially, UART plays the role of serial. The medium between UART and parallel interface is a bus composed of about 8 data lines (with some control pins) on one end, and two serial lines - RX and TX on the other end.

HDMI interface: A high-definition multimedia interface is a definition of connectors and cables. It can support high-quality and high-bandwidth video and audio streaming between devices.