TXB0108: SDCARD problem using TXB0108

Jesus Alvarez

Part Number: TXB0108
Other Parts Discussed in Thread: TXS0206, TXS0108E, STRIKE, TPD8F003

Hello.

We have designed a board based in Intel Edison with SDCARD socket.

We selected TXB0108 to do the sdcard voltage level translation as it was used by Sparkfun SDCARD Block (https://www.sparkfun.com/products/13041). In fact we have implemented the same schematic.

At first time it seems to work ok. However after some time working, some boards have lost the SDCARD functionality. The sdcard function just stop working (message in intel Edison console mmcblk1: "error -110 transferring data .....".

The sdcard is ok and the intel Edison is ok too as we have moved them to other carrier board and they work ok. So something in those carriers boards have failed.

The error is not intermittent as once they have failed, those boards have never ever come back to life in terms of sdcard functionality.

I can force the problem to appear in a new board by just removing the sdcard while system is powered (sdcard cleanly unmounted etc). So I am thinking in ESD or something that fries the TXB0108.

The sdcard slot we are using is : 2908-05WB-MG

Does anybody have an idea of what is going on?

Many thanks!

over 8 years ago

0 Clemens Ladisch over 8 years ago

Guru 316440 points

That schematic has no protection whatsoever:

The permanent damage indeed sounds like ESD; you might consider some six-channel ESD protection.

Could you check a damaged TXB chip if one particular I/O is broken, or all of them?

0 Jesus Alvarez over 8 years ago in reply to Clemens Ladisch

Prodigy 110 points

TXB0108 says it has ESD protection:

"8-Bit Bidirectional Voltage-Level Shifter with Auto Direction Sensing and +/-15-kV ESD Protect"

What am I missing?

Intel Edison arduino breakout board has TXS0206. We do not want to use BGA as they are difficult to inspect. Is there another option?
What about TXS0108?

0 aozer over 8 years ago in reply to Jesus Alvarez

TI__Mastermind 29905 points

Hello Jesus,

While it is true that the TXB0108 has some integrated ESD protection, I do not believe these devices were designed with live insertion in mind. I would recommend a dedicated ESD solution if you plan to support live insertion on your device.

0 Jesus Alvarez over 8 years ago in reply to aozer

Prodigy 110 points

I have been investigating and it seems the thing to look for is IEC 61000-4-2. That is the standard that guarantees a real ESD protection.

So can you please recommend something with no BGA package? TXS0206 is the perfect fit but that package is not error friendly.
I have seen that TXS0108 has IEC 61000-4-2 ESD protection. I think it is a almost direct replacement for TXB0108. What do you think?

Many thanks for the support

0 aozer over 8 years ago in reply to Jesus Alvarez

TI__Mastermind 29905 points

Hello Jesus,

Before giving any recommendation on a solution is there any way you could probe the pins during insertion/removal and provide us with some scope shots? I am hesitant to just recommend the TXS0108E without confirming that it is indeed an ESD strike causing your failures.

0 Jesus Alvarez over 8 years ago in reply to aozer

Prodigy 110 points

I will try.

I have a scope but I am using the smallest package for that IC.

BTW, what do you expect to see? Any other idea?

Thanks

0 aozer over 8 years ago in reply to Jesus Alvarez

TI__Mastermind 29905 points

Hello Jesus,

We would basically be looking for a large inductive voltage spike causing failure of the device. In the mean time, if you can get your hands on some TXS0108E samples, they will be pin for pin compatible with the TXB0108. You could try replacing the TXB0108 with the TXS0108E and see if you have better results.

0 Jesus Alvarez over 8 years ago in reply to aozer

Prodigy 110 points

In the mean time (I will measure with scope this weekend).

Would a TXS0108 + TPD8F003 make sense to have same functionality as TXS0206? ESD + EMI

Thanks

0 aozer over 8 years ago in reply to Jesus Alvarez

TI__Mastermind 29905 points

Hello Jesus,

I think that would be a good substitute.

Logic

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TXB0108: SDCARD problem using TXB0108