TXS0108E: Please confirm maximum data rate for SDIO interface.

Tool/software:

Dear TI experts,

My customer tests the performance of TXS0108E on their own PCB.

They test it for level transfer between eMMC memory and MCU.

Schematic is made using push-pull topology, so I think that it should be supported up to 110Mbps.

But regarding to the results of my customer,

- 4bit communication (25MHz) : working well.

- 8bit communication (25MHz, 50MHz) : not working.

And here are my questions ;

1. 110Mbps data rate means that the rate of total bit?

(i.e. 25Mbps(MHz) for 4bit communication, 25MHz * 4bit = 100MHz)

Or 110Mbps data rate support each bits?

2. Could you recommend bidirectional voltage level shifter which can work with SDIO 8bit communication? (should work with 50MHz clock frequency)

I attach the chstumer's schematic which used TXS108E.

e-MMC.pdf

Please check this issue. THanks.

Best regards,

Chase