Larry Bradley wrote:
> What is the normal way of handling this sort of thing? Are there 3.3
> volt to 5 volt buffer chips,etc?
>  =20

It's worth checking the specs of the 5V device you are driving, if an=20
input on the 5V device is advertised as "TTL compatible" it will almost=20
certainly have input thresholds that allow it to accept signals from a=20
3.3V CMOS device.

You can get dedicated level shifting buffer chips from various vendors=20
though finding the part numbers can be a bit tricky sometimes.

You can also use basic logic chips from the right families to level=20
shift, 74HCT logic running of 5V will give you 5V outputs while having=20
inputs that are compatible with both 5V and 3.3V signals, 74LVC or=20
similar running off 3.3V will give you 3.3V outputs while having inputs=20
that are compatible with both 5V and 3.3V. This techinique is especially=20
handy if you need a bit of glue logic in addition to the level shifting.

Someone else mentioned the mosfet level shifter trick, it's a neat trick=20
in the right scenario but be aware that it effectively creates the=20
equivilent of an open drain output so it's probablly not the best choice=20
if you need high speed.
--=20
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