AK4323 AK4325 AK4327 AK4330 AK4335 Why do I need the AK432X or AK433X cable for Touchscreens instead of the AK430X/AK4310?

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Many 4K USB-C touch screens use 4-Lane DP mode instead of the 2-Lane DP mode, for a USB-C cable made of copper this is not a problem but for a AOC cable it is a problem because there is a conversion taking place in the cable from an electrical signal to a light signal and this has to be converted again at the other end.

Below is an image of the pin use of a 2-Lane USB-C cable (AK4310). 

2 DP Lane.png

In this cable, 4 wires/pins are used for Video (Purple) and 4 wires/pins are used for Data (Orange).

So here you have 1 chip that converts data (orange) into a light signal and on the other side this is converted back into an electrical data signal. And the same goes for the video signal (purple).

When connecting a monitor using the 4-Lane DP technique, the 4 wires for Data are used for video as you can see in the picture below.

4 DP Lane.png

The Chip must then be able to deal with this to detect that no data but a video signal is being sent, this is not possible with the chip that is in the 2-Lane AOC cables. In the AK4335 there is an additional chip that determines the use of the cable, does it need 4 or 2-lanes for Video. When it needs 4-lanes it switches to a Chip using all 8 wires/pins for video signalling and for the touchscreen the USB 2.0 data (Green) is sufficient for the touchpanel to work. If it detects a display with USB-C and 2-lane is sufficient it will only use 4 pins for video keeping the other 4 pins for data transmission up to 10Gbps.

 

Additionally the AK4310 is only 10m the AK4335 has a length of 15m (but with a limitation of only 40W PD instead of 60W)

 

So since most 4K touchpanels need 4-lane for the video signal you will need an AOC cable that can do this: AK4323 (3m, 60W); AK4325 (5m, 60W); AK4327 (7.5m, 60W); AK4330 (10m, 60W); AK4335 (15m, 40W)