TTL interface of TFT-lcd LCD screen interface type

TTL interface of TFT-lcd LCD screen interface type

TFT liquid crystal screen refers to the liquid crystal screen that uses TFT to control the liquid crystal pixels, and it is the most commonly used type among many LCDs. lcd is the abbreviation of "Liquid Crystal Display" in English, which means liquid crystal display, which is often referred to as LCD screen; tft is English "Thin Film Transistor", which means thin film field effect transistor.

TFT-LCD is actually a component, that is, a liquid crystal screen component, which is mainly composed of a liquid crystal panel, a backlight, a light homogenizing film, a row and column drive circuit, and a timing control circuit (often called a logic board). The often said TFT-LCD interface refers to the interface between the LCD panel and the motherboard (also known as the signal processing board, or signal board), that is, the signal input interface of the logic board.

In the liquid crystal display, the TFT-LCD interface has TTL (RGB), LVDS, EDP, RSDS, TMDS and other types. Among them, the first three are used more. Here we will introduce the characteristics of the interface TTL interface and signal composition . TTL is the abbreviation of "Transistor Transistor Logic" in English, which means "transistor-transistor logic". TTL level signals are generated by TTL devices. TTL devices are a major category of digital integrated circuits. They are manufactured using bipolar technology and have the characteristics of high speed, low power consumption and many varieties. The characteristic of TTL interface is that the TTL interface belongs to the interface for data transmission in parallel. The TTL data signal output by the main control chip of the drive board is directly transmitted to the input interface of the LCD panel via the cable. That is to say, when the TTL interface is used, it is not necessary to use a dedicated interface circuit on the driver board side and the liquid crystal panel side of the liquid crystal display, but the RGB signal is directly sent to the TFT-LCD liquid crystal screen. Since the early digital processing chips used TTL, the TTL interface was mostly used in early LCD products, mainly small screens (generally no more than 15 inches) or low-resolution LCD screens, early LCD color displays or notebook computers The display used is basically TTL interface.

RGB data signal

(1) Single channel TTL

Single channel 6bit TTL output interface is also called 6bit single TTL interface. This type of interface has 18 R, G, B data lines, which are 6 red primary color data of R0～R5, 6 green primary color data of GO-G5, and 6 blue primary color data of B0～B5, a total of 18 data lines. Since the primary color RGB data is 18bit, this type of interface is also called 18bit or 18bitTTL interface.

(2) Dual channel TTL

Dual-channel means that there are two sets of RGB data, divided into odd and even channels. Some clocks are also divided into odd and even (OCLK, ECLK), and some share one. The dual channel 6bit TTL output interface is also called 6bit dual TTL interface. There are 36 RGB data lines for this type of interface, 18 odd RGB data lines, 18 even RGB data lines. Since the primary color ROB data is 36bit, this type of interface is also called 36bit or 36bitTTL interface.