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7MHz CLKIN for SN75LVDS83a

Other Parts Discussed in Thread: SN75LVDS83A, SN75LVDS82

Hi Team,

My customer want to use SN75LVDS83a, but their system clock only 7MHz.

Can they just connect their system clock 7MHz into parallel data in (D0-D23) and use external 14MHz for CLKIN?

Thanks.

Best regards,

Prescott 

  • Hello,

        Could you describe your application? I need more information because seems possible, but the clocks must be in phase, also take into account that this configuration is going to transmit the same input data twice.

    Regards,

    Diego.

  • Hi Diego,

    The customer's application is multi-function printer.

    The signal block diagram as below

    Can SN75LVDS83a and SN75LVDS82 work on this application?

    Is it possible to use 14 MHz CLKIN? Because my customer want to use 14 MHz CLKIN for this application.

    Or is there any concern on LVDS when using 35 MHz CLKIN such as LVDS cable..?

    And do we have any reference design document for SN75LVDS83a and SN75LVDS82 that can provide to customer?

    Thanks

    Prescott

  • Hello Prescott,

        Let me explain if I understood well:The SN75LVDS83A will transmit the data& the 7 MHZ clock decoded on the LVDS data (at 245MHz because the 7x internal PLL), plus the 35MHz differential clock. Meanwhile the SN75LVDS82 will deserialize the LVDS data and deliver parallel data (the video data & the 7MHz clock) plus the 35 MHz clock. So you want to discard the final output clock (35 MHz) and use the output data instead? (video data + 7MHz clock).

        This is not a typical application but seems possible, Please ensure that the printer board SoC accepts the output data from the SN75LVDS82.

    Regards,

    Diego.