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Frequency limit of TSW1200EVM or TSW1400EVM+ ADS5400EVM

Albert Vouillemont
Prodigy 10 points
Other Parts Discussed in Thread: ADS5400, ADS5400EVM

For a new design I need to evaluate the high speed 12 bit ADC ADS5400, so the shorter way is to use evaluation board.

I imagine using ADS5400EVM board + (TSW1200EVM or TSW1400EVM) board.

My question is about the maximum clock frequency that I can make the ADS5400EVM working.

In the PDF slwu079.pdf : User’s Guide : TSW140x High Speed Data Capture/Pattern Generator Card the following sentence : page 7/55 “For one-channel parallel DDR sample-wise data formats, 14 of the LVDS data pairs are used to support up to 14-bit-resolution ADCs at up to 500-MHz sampling rates.”, seem to be a drastic limitation.

Can you confirm me that the ADS5400EVM + TSW1400EVM does not enable test faster than 500 MSamples/s and if not what is the working limit frequency?

Does the EVM1200 + ADS5400EVM can solve the task to make the test at 1 GS/s or at least 650 MS/s.

Best regards.

  • 0
    TI__Mastermind 29220 points

    Hi,

    The ADS5400 can output either a single 12 bit LVDS DDR bus at sample rate (which would be 1000Mbps on the LVDS if the sample rate is 1000MHz) or it can output two samples at a time in dual bus mode using 24 LVDS DDR at half the sample rate.  This allows for an easy tradeoff between the number of pins used for the interface vs. the speed of the interface.  The connector on the EVM has all the pins needed for single bus or dual bus operration.   The EVM for the ADS5400 has a jumper on posts for single bus or dual bus selection, so it is easy to choose which interface you want.

    The TSW1400 can accept the samples from the ADS5400 in either single bus mode at up to the full 1000Mbps or in dual bus mode which cuts the data rate in half.  There is a device selection in the GUI for the TSW1400 for ADS5400-1bus and another device selection for ADS5400-2bus.  So there is no speed limitation placed on the EVM by the TSW1400 up to the max sample rate of the ADC itself.

    The TSW1405 can also work with the ADS5400 at the max sample rate of the ADC but the firmware for the TSW1405 was only written to support dual bus mode.  (The FPGA on the TSW1405 is just fast enough that the firmware could have been written to accept single bus mode at 1000Mbps, but it wasn't.)  Still, in dual bus mode there is no limitation on the max sample rate of the ADS5400 EVM into the TSW1405 up to the max sample rate of the ADC.

    The TSW1200 also supports only dual bus mode from the ADS5400 EVM, which means that there is again no limit on the max sample rate of the ADC up to the data sheet max for the ADC itself.  But the TSW1200 is an older capture card that will not be supported with future upgrades or revisions so the TSW1400 or TSW1405 would be a better choice.

    Regards,

    Richard P.

  • 0 in reply to Richard Prentice
    Mastermind 9165 points

    Hi Albert, Richard,

    This is great post and answers most of my question, Thank you!!

    Here, I would like to highlight one thing in Richard's reply to Albert.

    "The EVM for the ADS5400 has a jumper on posts for single bus or dual bus selection, so it is easy to choose which interface you want."

    The output format of ADS5400 is selectable either a single or dual bus mode via register and I don't see any jumpers on ADS5400EVM which is related to output mode selection. Here are some quotes from datasheet and EVM userguide.



    Please let me know, if I miss something.

    Thanks,
    Ken