Is this buffer sufficient?

[chipwitch]

I am connecting an SD card reader to an Arduino MCU proto board.  The sketch uses SPI to interface with the SD card.  Since the Arduino data pins are 5v and the card reader is 3.3V, I'm using a hex buffer to level shift.  All of this is new to me, except for the Arduino part.

A trusted source has indicated that these card readers can often draw 100 mA or more when writing data.  Okay, so the same trusted source also specifies a couple level shifters for the project.  I found some other ones, but when I checked the datasheet, I found that the I_O was only 35 mA per pin!  I went back to my the trusted source and checked the datasheets for two of the parts she specified.  Their I_O's were even less. 

It would seem that either I'm not reading the datasheet correctly, or my "trusted source" is wrong.  The latter of which seems highly unlikely.  She is well respected in the Arduino community and a EE if I'm not mistaken.

Am I reading the datasheet right?  It won't handle the load right?  Will I need to throw in some mosfets or something?

[MK14]

Surely the 100 mA or more, is talking about the power supply requirements for the SD card (supply rails). NOT the logic lines. ?

Programming flash (SD cards etc), can indeed use lots of current, during writing.

[MK14]

Just to confirm. The following official looking (micro) SD spec:

http://www.dtt8.com/images/micro-sd%20specification.pdf

Seems to say that the POWER CONSUMPTION, can be similar to the 100 mA figure in your OP.

But the logic lines, will be a tiny, TINY fraction of that amount. MASSIVELY below the 35 mA or whatever, of your buffers.

SD cards, have been designed to use relatively small amounts of electricity, because mobile phones, cameras etc, have relatively small batteries.

[chipwitch]

You're right.  Thanks to both of you.  I went back and checked.  She just said over 100 mA.  She didn't say it was coming from the data pins.  She wasn't specific about it at all.  Of course, now it makes sense.  Thanks for the link.  I couldn't find any datasheets for my module, but your link has some useful info. 

Cheers