TLK10022: Placing 8 TLK10022 chip on one MDC/MDIO bus

Reza Anvari

Part Number: TLK10022
Other Parts Discussed in Thread: TXB0108, LSF0204D

Hi,

I am going to manage 8 TLK10022 chips over a common 3V3 MDC/MDIO bus.

Could you suggest a voltage translator/ buffer (3V3 to 1V8), with partial power down mode feature, meaning IO's on each side Hi-Z when any of the 2 VCC's is off for the MDC/MDIO lines?

1- For UNI-DIR MDC.

2- For BI-DIR MDIO. this needs to be open drain.

Thanks,

Reza

over 2 years ago

0 Rodrigo Natal over 2 years ago

TI__Mastermind 19135 points

TI does have a family of voltage translator products. You may consider TXB0108 from TI, see link below.

https://www.ti.com/product/TXB0108

Thanks,

Rodrigo Natal

0 Reza Anvari over 2 years ago in reply to Rodrigo Natal

Prodigy 60 points

Hi Rodrigo,

TXB0108 has push pull configuration and it won't work for MDIO.

Below is a quick sketch for 8 MDIOs from TLK10024's which are connected to a single master node.

I was thinking about LSF0204D which has open Drain IO configuration, your thoughts?

Regards,

Reza

+1 Rodrigo Natal over 2 years ago in reply to Reza Anvari

TI__Mastermind 19135 points

Thanks for clarification. I did see another TI 8-bit translator part number, TXS108E, that supports open drain but it appears its max data rate for that mode is 1.2Mbps. LSF0204D however looks like a better fit as it supports up to 100MHz and MDIO is listed as a supported application on its datasheet. Assuming 4-bit part number works for you then LSF0204D should be fine.

Thanks,

Rodrigo Natal

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TLK10022: Placing 8 TLK10022 chip on one MDC/MDIO bus