TXS0108E: AM3358BZCZ100 can't boot from SD Card after level were converted from 1.8V to 3.3V

Prodigy 20 points

Replies: 2

Views: 42

Part Number: TXS0108E

Hi

I configed the MMC0 of AM3358 to SD Card interface but power supply is 1.8V to match other functional requirement, used the TXS0108E as voltage translator.

I think the data rate isn't the cause as TXS0108 can up to 60M in my application.

Is it because the Initialization and Identification between it and Host (AM3358) cannot pass? If yes, how can I modify the host driver?

Please help to advise, thanks!

BR 

TC Liu

The schematic as below

2 Replies

  • 60Mbps

  • The TXS has integrated pull-up resistors; you do not need the external ones.

    The resistors R9/R22/R23/R24 create voltage dividers with the internal pullups; unused I/Os should be simply left open.

    I notice that there is no pull-up resistor on the CLK line. Would the TXS's internal pullups be harmful?

    Can you show oscilloscope traces of when the AM3358 tries to boot?