Electronic – Difference between LVDS SerDes and FPD-Link III SerDes

interfacelvdsvideo

I'm new to the world of video interfaces and am working on a project in which parallelized video stream data is transmitted and subsequently received by processing components on the other end of an interface. I've been exploring several different technologies such as FPD-Link, but I am uncertain about how it is different from existing LVDS SerDes given that it implements LVDS. Is it just the back-channel and built-in signal integrity tech? Why would one choose FPD-Link for over standard LVDS?

Best Answer

Actually, what you call as "LVDS SerDes", is actually the first generation FPD-Link. It defines how parallel video data is serialized with the clock in the SerDes, and the resulting signals are sent over a DC coupled LVDS electrical interface.

Second generation FPD-Link just used higher bit rates and embeds the clock in the data stream and supports AC coupling, so singe twisted pair could replace complete first generation FPD-Link.

Third generation FPD-Link change from LVDS to CML electrical interface to use even higher bit rates, and it also supports bi-directional communications, so no extra wiring is necessary for a display interface, so panel information can be read via I2C for example.

So, in short, you are comparing first-gen and third-gen FPD links. Newer tech allows faster rates over less wires and bidirectional communications for status and control