Bob Axtell wrote:
> No this is correct. Even the PIC F33 series can accept 5V inputs into the
> 3.3V part. The LVC07 is an open collector part, so can drive a 5V device
> as long as it is pulled up to 5V.

I figured that would be the case, but I'm more interested in the LVC14, 
which claims to take a 5V input even with a 3V Vcc... Near enough every 
electronics book I've seen (or at least those new enough to cover TTL 
logic) makes a big deal about not putting signals above Vcc into TTL or 
CMOS inputs, unless you're deliberately trying to make the chip go into 
a latch-up condition.

 > be careful of the pullup resistor size,
> there is a limit to the amount of current it can sink. The PIC F33, for
> example, can only sink or source 4Ma max from a pin.

The LVC14 is only going to be driving one CMOS load; the LVC07 has a 
24mA drive capacity so should be OK on anything down to about 220 ohms 
worth of pull-ups (or about four 1k pullups in parallel if someone has 
fudged the termination setup on the drives).

Thanks,
-- 
Phil.
piclist@philpem.me.uk
http://www.philpem.me.uk/
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