What are the types of interfaces available for LCD screens?

LCDs have a wide range of interface types, the most commonly used interfaces are mainly RGB, MCU, LVDS and MIPI interfaces. In this article we will briefly introduce the structure principle of these LCD interfaces.

1. RGB interface

The RGB interface of an LCD panel is a colorful combination of three colour channels: red (R), green (G) and blue (B). Therefore, the RGB interface of an LCD screen is the video interface that is divided into three primary colour inputs. Usually a colour channel is represented by 8 bits, i.e. the value of each colour channel ranges from 0 to 255, usually referred to as RGB888/RGB24. The three colour channels can combine to produce a total of about 1678 (256 x 256 x 256) million co-lours, abbreviated as 16 million colors or 10 million co-lours, also known as 24-bit co-lours. In practice, in addition to RGB888/RGB24, there are also RGB555, RGB565, RGB32, RGB666 and so on.

2. MCU interface

The MCU interface of the LCD is mainly for the field of micro controllers. The MCU interface standard is the 8080 bus standard proposed by Intel, so in many documents the I80 is used to refer to the MCU interface screen. Data bits are transmitted in 8-bit, 16-bit, 18-bit and 24-bit. Connections are divided into: CS/RS/RD/WR/. The advantage is that the control is simple and easy, no clock and synchronization signals are required. The disadvantage is that it consumes GRAM, so it is difficult to achieve large screens, and is generally used below 4". For MCU interface LCM, the internal chip is called LCD driver. The main function is to transform the data/commands sent by the host into RGB data for each pixel to be displayed on the screen. This process does not require a dot, line or frame clock.

3. LVDS Interface

The LVDS interface for LCD screens is Low Voltage Differential Signaling, a low-voltage differential signal technology interface. The LVDS output interface uses a very low voltage swing (about 350mV) to transmit data through a differential on two PCB alignments or a pair of balanced cables, i.e. low voltage differential signaling. The LVDS output interface enables signals to be transmitted at several hundred Bit/s on differential PCB lines or balanced cables, with low noise and low power consumption due to the low voltage and low current drive method.

4.MIPI interface

MIPI (Mobile Industry Processor Interface) is an open standard developed by the MIPI Alliance for mobile application processors. DSI (Display Interface) and CSI (Camera Interface). CSI/DSI refer to their bearers for Camera or Display applications respectively, both with complex protocol structures.

In the process of LCD LCD selection and customization, the type of LCD interface used is mainly based on the interface of the motherboard, which is matched by the software driver to light up the screen and thus realize the product display solution.