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BLVDS device

Wystan Zhu
Intellectual 860 points
Other Parts Discussed in Thread: DS92LV16, DS92LV18, SCAN921226H, SCAN921821

Hi, team,

Do you have BLVDS device now?

Br,

Wystan,

  • 0
    TI__Expert 3050 points

    Hi Wystan,

    We have many BLVDS devices. What type of device are you looking for? We have serializers, deserializers, tranceivers and more. We have devices that handle 10, 16 and 18-bit payloads over a wide range of clock frequencies.

    Please share more details about your application so that I can help you select the appropriate device(s).

    If you would like to browse through some devices, here are a few to look at:

    - DS92LV16

    - DS92LV18

    - DS92LV1021A

    - DS92LV1224

    - SCAN921226H

    Mike Wolfe

    DPS APPS / SVA

  • 0 in reply to Mike Wolfe
    Expert 1140 points

    Hello,

     

    We are using the DS92LV18 chip on a SCAN921821 evaluation board.

    If we drive REFCLK and TCLK from a crystal oscillator, then the chip does not work (not Rx and not TX).
    we see that the TTL clock is loaded and instead of 0-4V we see 0 - 0.8V.

    We tried about 10 TTL oscillators, different frequencies and different manufacturers and it is all the same.

    However, if we drive the chip from a signal generator with 50 Ohms output, then both devices work and we can transmit data from one side to another .

    My question is whether we go wrong? The datasheet says that the device is LVTTL or LVCMOS compatible with input current of only few mA!

    Do we have to use a high current buffer? If yes, please recommend one.

     

    Best Regards,

    Avi Aharoni

     

     

  • 0 in reply to aronii
    TI__Expert 3050 points

    Hi,

     

    Can you specify which connectors you are using for your test? All of the input traces to the SCAN921821 have 50ohm shunt terminations on their inputs, which could be why your source is having trouble maintaining the propper logic levels.

    If you do not use a 50 ohm shunt termination on the LVCMOS inputs, you will not require a high currrent buffer.

     

    Mike Wolfe / DPS APPS

  • 0 in reply to Mike Wolfe
    Expert 1140 points

    Thanks for your advice. This is probably th ereason why it works with a finction generator and not usinjg a standard oscillator.

    Can you recommend such a buffer for me?

     

    Avi

  • 0 in reply to aronii
    TI__Expert 3050 points

    Hi,

     

    The 50 ohm shunt terminations are there as an option. They are meant to assist you in interfacing the evaluation boad with various test equipment and are not requried for all use cases. If you are attempting to drive the inputs with a high impedance driver rather than a 50 ohm source, then you can remove the resistors from the evaluation board.

     

    Mike Wolfe / DPS APPS