Bus voltage translation

What speed are you running the interface at?

Is each signal unidirectional?

If they are all unidirectional signals, and the 5V board has TTL compatible inputs, you don't need to do anything from the 3.3V -> 5V domain.

In the other direction, you can either use a device with 5V tolerant inputs (most of the 74AHC range) or just use a resistive divider for relatively slow signals.

If everything's high speed, then a translator may be better

Here's TI's offerings - others (Philips, Fairchild, OnSemi) make them as well

Dual supply:

Single supply:

Translating bus switches if you have bidirectional signals:

Cheers

PeteS

SN74ALVC164245 is an absurd part number, but it works fine.

John

Cheers for the help

I've found a dual supply bus translator from fairchild which should do the job.

Steve Minshull

PeteS wrote: