Connecting 3.3V to 5 V

[raivo]

Does anyone know how 3.3V device can be connect to 5 V bus?
I need to use 3.3V (SmartMedia) memory cards with one microcontroller system that works only on 5V. 3.3V power is easy to make but are there some chips or some simple tricks for connecting two buses with different voltages?

Raivo Nael

 

[xnuke]

Try this application note:

http://www.philipslogic.com/support/appnotes/an240.pdf

 

[designchain]

The Philips app note above is a rather old approach (the app note is dated 1995 - watch out for obsolecense!). Look at bus switches. These are made by IDT, TI, Fairchild, Pericom, and others. They have (effectively) near-zero delay, same pinout as standard logic devices (for those they can replace in certain applications), are multi-sourced, and are designed specifically for this task. A typical app note on the subject is

http://www.idt.com/docs/AN_11.pdf

. By the way, I have no affiliation with any of these companies. I have specified parts in the bus switch logic families to perform precisely this function. They work.

 

[xnuke]

Thanks for the update, designchain.

 

[raivo]

Thanks for all! This is exactly what i needed!

Raivo