Reliability Issues: MiniSD Card Connection

[danonboost]

In a recent design I used a miniSD card "push-pull" style connector.

The information stored on the card is positioning data from a GPS. The problem is that sometimes the data gets corrupted --some units are much worse than others and most of them never have any issues at all. The corruption happens when it's sitting on the floor of the car and there is some vibration. We are talking about a VERY small amount of vibration. A correction we made in software detects a corruption and then continues instead of corrupting the entire log (that's not a real fix in my opinion since data is still missing in the end).

If I put some material between the holder and card forcing it down on the contacts the problem goes away. I will probably need to get in touch with Hirose or switch to a Molex....?

Anyone have any experience with this?

Spec/datasheets:

http://www.hirose.co.jp/cataloge_hp/ef_60900063.pdf

http://media.digikey.com/pdf/Data Sheets/Hirose PDFs/DM2A-SFW-PEJ-S(03).pdf

I appreciate any help!

dan

 

[itsmoked]

No can help but I'm interested too. Certainly sounds like a lousy connector.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[mcgyvr]

Switch to a different card holder.
Watch out for long lead times from Molex though. They have been getting pretty bad lately.

 

[MacGyverS2000]

They may be hiding their vibration data. Recently we were having a vibration issue with some Lemo connectors when attached to an Odu connector... the Lemo would practically self-destruct over a short period of time (we're using them as A/V connectors in a racing camera system for F1 cars). We ended up going with both connectors being Lemo and using a mounting block that held them steady. You may have to do something similar with the SD card holder, some form of custom mounting block that gives more pressure to the card after it is inserted.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[IRstuff]

I think that you'll find that consumer products will not had connector insertion forces that are required to do the job, since most consumer applications of SD cards do not involve much in the way of vibration.

Since the connector contacts are all in-plane, it may be possible to re-orient the connector and card to minimize the vibration effects by either flipping the assembly or rotating it 90º.

Obviously, in many high-vibration applications, isolators are mandatory, so that's another avenue.

TTFN

FAQ731-376

 

[melone]

Was your connector designed for a "high-vib" application?

 

[danonboost]

Thanks for the feedback/input. I'm going to try and sample a Molex version and see if will help. I'll report back.

It's not so much that it fails under "vib" testing but just moving it around like you would your cellphone. It's pretty pathetic in my opinion that it has problems with the level of "vibration" it is being exposed to.

 

[richs]

Hiya-

You might want to switch to a micro SD card. If memory serves me right, the "profile cards" of cell phones are micro SD. If, and that's a big if, those connectors are available standalone, they might be worth looking into. I remember recently seeing a picture of one of the new phones that had the micro SD card placed in the phone and a latch cover over the top.

Drat, I can't remember the "term" for the "profile cards", SIM card?

Just a thought. Also, would a USB memory drive, assuming space allows, be a more robust connector? Of course it would involve a USB interface and a lot of code change.

Cheers,

Rich S.

 

[itsmoked]

Good point richs. Those are much more robust. They are also 1/10 the weight so vibration would be less of an issue in the first place.

Maybe "microSD" ??

Keith Cress
kcress -

http://www.flaminsystems.com