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TCA9617: Can MDIO/MDC signals be transmitted?

Chance Zhan
Prodigy 200 points

Part Number: TCA9617
Other Parts Discussed in Thread: TXS0102, LSF0102

The customer's use case is converting MDIO/MDC signals from 1.8V to 3.3V, but the 9617 supports I2C signal transmission. Can it support MDIO/MDC signal transmission? Is it just a matter of meeting the voltage level conversion requirements?

  • 0
    Guru 327970 points

    The TCA9617A/B were designed for I²C, but can indeed convert other open-drain signals as long as the timings and voltages match.

    The TXS0102 is faster, but its edge accelerators are more sensitive to noise.

  • 0
    TI__Prodigy 200 points

    Hello, Clemens. Which specific timing requirements are you referring to? What kind of requirements do I need to meet?

  • 0 in reply to Chance Zhan
    TI__Intellectual 1860 points

    Hi Chance, 

    Is there a schematic I can take a look at? In theory you could use the TCA9617 for any open-drain signal, but it might be better to move to a different device that is more suited for this type of signal. Is it possible to use a different device such as the TXS0102 that Clemens mentioned or maybe the LSF0102? If you could provide more information on the application of the TCA9617 (such as what is connected to it, speed, etc.) I can provide more information about the best part to use.

    Regards,

    Jason

  • 0 in reply to Chance Zhan
    Guru 327970 points

    Tha TCA9617A datasheet specifies the propagation delays. They are designed to work with 1 MHz I²C.

    In the SMI protocol, the PHY has to provide the MDIO signal at most 300 ns after the rising edge of the clock. With both the clock and the data signal delayed by the translator, you must use a lower clock frequency to allow the data to arrive when the MAC tries to read it. (I do not know what MAC you are using, when it samples the input MDIO line, and whether it can be configured to use a slower clock.)