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ISO3086T: The four channels' single-end to differential signal for SPI

Part Number: ISO3086T
Other Parts Discussed in Thread: AM26LV32E, ISOW7840, ISOW7740, AM26LV31E, AM26C31, AM26C32, SN65C1167E

Hi team,

As show in blew picture, the four single-end SPI signals need to be transferred to differential signals after isolated. Do we have the quadruple-differential line driver?

  • Hi Steve,

    Thank you for reaching out.

    We currently do not have isolated quadruple differential line drivers but I believe we have non-isolated quadruple differential line drivers. I will notify the transceiver product group to suggest a suitable device to you, thanks.


    Regards,
    Koteshwar Rao

  • Yeah, I have noticed the AM26LVE and AM26LV32E devices, which is non-isolated quadruple differential line drivers.

    For isolation, I also find that ISOW7840(4)/ISOW7740(4), I want to confirm that if any other solutions for this case.

  • Hi Steve,

    So we have 2 main choices that we like to present with quad differential line drivers/receiver

    1. AM26LV31E (differential RS-422 driver, 3.3V supplies) + if you need a differential receiver AM26LV32E (Differential RS-422 receiver, 3.3V supplies)

    2. AM26C31 (Differential RS-422 driver, 5V supplies) + AM26C32 for the differential receiver. 

    Since you are doing SPI however I don't know if the quad is the best way to move:

    From Host's perspective only MOSI, NSS, and SCLK would be used with the driver and the MISO line would need a receiver - but it could be a single RS-485/RS-422 device (depending on speed needed - something from the THVD15xx or THVD14xx line may work) 

    Another possible solution is to utilize SN65C1167E. It is a 2 channel full duplex RS-422 transceiver which means it has two independent RX channels and two independent TX Channels 

    1. MOSI and SCLK could use the 2 TX channels 

    2. MISO could use one of the RX channels with the other unused

    3. NSS generally wouldn't need to be differential because its slow comparatively  to the other signals and when we see RS-422 using SPI signals the NSS line is typically not directly routed through transceiver - so after isolator in your app generally its kept single ended. However if you do need this to be differential using a device in the THVD15xx or THVD14xx families depending on speed need would be a good option.

    4. This device is 5V supplied only - so if you don't have a 5V rail available the best option is the AM26LV31E (TX)  and AM26LV32E (RX)

    Please let me know if you have any other questions!

    Best,

    Parker Dodson