DVP, LVDS and MIPI

DVP, LVDS and MIPI

The difference between MIPI interface and LVDS interface

The differential signals in the two interfaces cannot be directly interconnected. To be precise, they cannot be used after interconnection. MIPI DSI conversion to LVDS is relatively simple. There are ready-made chips. LVDS conversion to MIPI DSI is more complicated. Special modules, and the principle is more complicated.

Secondly, their main differences are summarized in two points: 1. The LVDS interface is only used to transmit video data, MIPI DSI can not only transmit video data, but also transmit control commands; 2. The LVDS interface mainly uses RGB TTL signals in accordance with SPWG/JEIDA The format is converted into LVDS signals for transmission, and the MIPI DSI interface transmits video data and control data required for screen control according to a specific handshake sequence and instruction rules. DVP is parallel port transmission, with slower speed and low transmission bandwidth.

LVDS

The LVDS output interface uses very low voltage swing (about 350mV) to transmit data through differential on two PCB traces or a pair of balanced cables, that is, low-voltage differential signal output. The LVDS output interface enables signals to be transmitted on differential PCB lines or balanced cables at a rate of several hundred Mbit/s. Due to the low-voltage and low-current drive mode, low noise and low power consumption are realized.

The composition of the LVDS interface circuit: In the liquid crystal display, the LVDS interface circuit consists of two parts, namely the LVDS output drive circuit on the driver board side (LVDS transmitter) and the LVDS input interface circuit on the liquid crystal panel side (LVDS receiver). The LVDS transmitter converts the 17L level parallel RGB data signal and control signal output by the main control chip of the driver board into a low-voltage serial LVDS signal, and then transmits the signal to the liquid crystal through a flexible cable (line) between the driver board and the LCD panel The LVDS receiver on the panel side converts the serial signal into a TTL level parallel signal and sends it to the LVDS receiver on the LCD panel side. The LVDS receiver then converts the serial signal to a TTL level parallel signal. , Sent to the LCD screen timing control and row and column drive circuit. In the process of data transmission, a clock signal must also be involved. The LVDS interface uses differential signal pairs for both data transmission and transmission clock transmission. The so-called signal pair is just each data transmission channel or clock transmission in the LVDS interface circuit. The output of the channel is two signals (positive output and negative output). It should be noted that different LCD displays have different LVDS transmitters on the driver board. Some LVDS transmitters are one or two independent Some of the chips are integrated in the main control chip.