DS90UB928Q-Q1: 1280x800/18 display on a 10m STP Cat.6 cable

Vladimir Skorepa53

Part Number: DS90UB928Q-Q1

Hi,
we use your products DS90UB928 and DS90UB927 in interactive driver terminals in public transportation.
As we try to use new display with higher resolution, we have faced frequent, short and random problems with lost synchronisation at deserializer side (which produce graphic errors).

Details of our design:
- FPD link III connection via 10m STP Cat.6 cable
- Last stable graphic configuration: 1024x600/18
- Current unstable graphic configuration: 1280x800/18

At that unstable resolution 1280x800/18 is LVDS clock at aprox. 71 MHz (no spread spectrum activated). There is stated maximum LVDS clock frequency 85 MHz in the datasheet that leads to decision that it should be working.

At what highest resolution do you achieve a steady picture when using a 10m STP Cat.6 cable?

over 6 years ago

0 Hamzeh Jaradat over 6 years ago

TI__Guru* 83530 points

Hello,

We do not use and we do not recommend to use the Cat 6 cable. In our data sheet we specify only by using 100ohm STP/STQ cable with HSD connector, i.e. impedance controlled connectors.

By using another impedance cable, which the Cat 6 has, and using another connector (not 100 ohm impedance controlled), you will get losses and impedance mismatching, so it is normal to have issues if you increase the PCLK.

0 Vladimir Skorepa53 over 6 years ago in reply to Hamzeh Jaradat

Prodigy 20 points

Thank you very much for your answer.

Have a nice evening,
Vladimir Skorepa

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DS90UB928Q-Q1: 1280x800/18 display on a 10m STP Cat.6 cable