Smart Card Interface

[Sylvain Munaut]

Hello,

I'm wondering if anyone here as recommendation / chips to use, to
interface to a smart card (ISO7816) ? I mean to support both 3.3v and 5v
cards and ensure it meets specs ? Is there any chips that do that ?
(preferably easy to find

Any guide / reference / advice is appreciated.


Thanks,

Sylvain

 

[Kryten]

"Sylvain Munaut" <com.246tNt@tnt> wrote in message
news:4249910d$0$325$ba620e4c@news.skynet.be...

I'm wondering if anyone here as recommendation / chips to use, to
interface to a smart card (ISO7816) ? I mean to support both 3.3v and 5v
cards and ensure it meets specs ?

Are there any chips that do that ?

Oh yes, it is a big and growing market.
Go google.

Philips make such chips and have data sheets on their site.

(preferably easy to find

Indeed, they might send you a sample if you pretend you might need millions.

There are several designs for card readers on the net, which do not use
anything exotic.

I adapted a smart mouse (which has such a simple circuit) to be 5V/3V
switchable.

You might make this switched by a spare handshake line so that your PC COM
port or whatever can do the appropriate power testing. IIRC, it tries one
voltage and if no response tries the other. 3V cards are designed to survive
5V but not respond at that voltage. I suspect the reverse is not guaranteed
for all 5V cards since they may have been designed before the idea for 3V
cards arose.

And BTW, IRRC it is 3V and not 3V3, for some reason.
I guess it lets them work longer in mobile phones as SIM cards.
Some also work at 1V8.