DS90UH948-Q1: AC coupling capacitor over coaxial cable

Shinji Tsuji

Genius 14179 points

Part Number: DS90UH948-Q1

Hi team,

I have a question about AC coupling capacitor value of FPD-LINK3 devices.

I plan to design DS90UH948 display which can be connected to either UH941 or UH947 over coaxial cable.

Recommended AC coupling value in the datasheet is

For UH947 : 0.033uF (0.015uF to GND)

For UH941 : 100nF (47nF to GND)

If I need to communicate with both serializers, how much is the recommended AC coupling capacitor at coaxial cable?

regards,

over 3 years ago

0 Ben Dattilo over 3 years ago

TI__Mastermind 25765 points

Hello,

For the AC coupling caps on RIN0+/- of the 948, you should be able to use 0.033uF. This is what is used on our 948 EVM, which can be used with both 947 and 941AS.

Regards,

Ben

0 Shinji Tsuji over 3 years ago in reply to Ben Dattilo

TI__Genius 14179 points

Hi Ben,

In case the video source board(947, 941AS) are designed by other vendors and the AC coupling capacitors on their 947/941AS

are different from 0.033uF, is it still OK to just use 0.033uF for UH948?

For example

UH947 -- 0.033uF -- cable -- 0.033uF -- UH948

UH941AS -- 100nf -- cable -- 0.033uF -- UH948

regards,

+1 Casey McCrea over 3 years ago in reply to Shinji Tsuji

TI__Guru** 103215 points

Hello Shinji,

Yes, both configurations are acceptable for 94x -> 94x

Best Regards,

Casey

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DS90UH948-Q1: AC coupling capacitor over coaxial cable