Clock for DS90UB903/904

Roland Kuebler

I would like to use the DS90UB903/904 with a QVGA display. Unfortunately the typical pixel clock frequency of this display is specified with 6.4MHz which is below the min. 10MHz for the Serializer. Increase the frequency to 12MHz is working using cables < 2m. Unfortunately I need a cable length of 10m. Increasing the pixel clock further (> 30MHz) is not an option as the display will not display pixels correctly anymore. Is there any other way around this problem?

over 12 years ago

0 Michael Peffers over 12 years ago

TI__Mastermind 20820 points

Hi Roland,

Somebody is looking into this and will reply shortly.

Regards,

Michael Peffers

High Speed Interface Applications Engineer

0 Mark Sauerwald88474 over 12 years ago

TI__Genius 13475 points

Roland

You might try looking at the DS90UB925 and 926 pair. These, like the '903/904 are FPD-III family products so they share many of the same feaures but the 925 and 926 were designed specifically for display interfaces, and support lower pixel clock frequencies and wider data paths.

Mark

0 Roland Kuebler over 12 years ago in reply to Mark Sauerwald88474

Prodigy 30 points

Hello Mark,

Thanks for the prompt reply. Does the 925/926 also have an optimum frequency to achieve the maximum cable length of 10m? (see 903/904 Pg.34 -> optimum for 10m @43MHz)

0 Mark Sauerwald88474 over 12 years ago in reply to Roland Kuebler

TI__Genius 13475 points

Roland

The 926 deserializer has an adaptive equalizer in the receive section which will allow it to adjust for various cable lengths. The actual cable length will depend upon the particular cable used, but 10m should be well within the capabilities of a decent quality cable.

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Clock for DS90UB903/904