NVT4858 SDIO Redriver

[bluewisefin]

I'm working with a 50 MBps microSD system and I want to adapt the micro SD slot to an SD slot. Can I use the NVT4858 to redrive the bus longer than 100mm? Right now if I use a passive 50 ohm flex I get write errors on the system logs.

[guoweisun]

HI bluewisefin

That should be OK but anyway please review the layout app note attached.

Hope this could help you!

[shichinhuang]

Hi @guoweisun ,

I also want to enhance the SDIO signal driving strength, the total length is about 150mm from i.MX93 SOC to SD card socket. The maximum operating voltageis of VCCA is 1.95 V in NVT4858 datasheet, but the host (i.MX93 SOC) will drive 3.3V SDIO signal level to the SD card for the communication in SD card initial stage before data transaction. Is it acceptable that the signals level is 3.3V signal level but to apply 1.8V on VCCA ? (see the green of following picture)

What do you think about this concern ?