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Application using LMH0340-->LMH0394-->LMH0341 other than SDI data rate

Guru 19785 points
Other Parts Discussed in Thread: LMH0340, LMH0341, LMH0394, DS32EL0124, DS32EL0421

Hi Team,

Our customer currently uses LMH0340, LMH0394 and LMH0341 in their SDI application.

Now they are considering to use these devices for 144Mbps×20bit=2.88Gbps. I believe these devices are designed for SMPTE standards, however, can you use these devices for such data rate ?

Best Regards,
Takushi Kawai

  • Hi Kawai San,

    The LMH0340/41 support standard SD, HD and 3G rates, we need to check if it supports 2.88Gb/s. The AE of these parts will advise once he finds out.

    Regards,

    TK Chin

  • Kawai-San,

    As TK mentioned these devices are characterized and qualified at SDI data rates. If used at other rates we cannot guarantee data sheet specifications.

    For non SDI data rates, you may consider DS32EL0124 and DS32EL0421 devices. These devices have the same architecture as LMH034/341 and can support the data rate you are interested in.

    Regards,,nasser

  • Hello TK-san, Nasser-san,

    Thank you for the information.

    I have asked customer to use DS32EL0124/0421, however, they do not prefer these device because they could only use the registered devices in their company.

    I have received another question from the customer.

    How about using 148.1818MHz which is output from FPGA internal PLL ? (74.25 x 34/33)
    Regarding your answer, I believe this usage would not be guaranteed. They would need to use 74.25MHz or 74.175...MHz.

    Customer's reference clock would be 72MHz in their application.
    I appreciate it if you could tell me a device or solution which could satisfy customer's requirement.

    Best Regards,
    Kawai

  • Kawai-San,

    Since 148.1818MHz is not a standard SDI frequency, i am thinking they would need to use a general off the shelf device like DS32 and do register programming. I thought their FPGA may be able to do this limited programming. Please note DS32EL0124/0421 is register compatible with LMH0340/341 so the change should be minimal for them. I apologize but i cannot think of any other device that could do this without programming the registers. 

    Regards,,nasser

  • Hi Nasser-san,

    Thank you for your great support.

    As you mentioned I couldn't find any other devices. I will continue asking them to consider these DS32EL0124/0421 devices. I will also ask if they can make the clock frequency higher than 125MHz using FPGA.

    Best Regards,
    Kawai