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Re: [N8VEM-S100:1282] LAVA-10 Zener Diode = 1N5226 (3.3v)

Actually the 74lvc244, 245 etc are available at mouser and digikey in dip sockets at very reasonable price - I am finding Jameco not as good for some chips any more so you need to shop around a little.

On Sunday, January 6, 2013 4:20:43 PM UTC-6, monahanz wrote:

Could use these, in general I like to stick to DIP chips with sockets (and a Zener in this case). Surface mount tend to be a little tricky for some.   There is plenty of space on this board.   There are DIP “level changers” also, but outfits like Jameco don’t stock them.


As a general question, how do people feel about surface mount chips?  I currently working on plans for a 80386 RAM board where capacity is an issue.   Do most people fee that could solder SM RAM chips to a board. Really would increase board capacity for pseudo-RAM chips.





John Monahan Ph.D

e-mail: mon...@vitasoft.org

Text:    mon...@txt.att.net



From: n8ve...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of yoda
Sent: Sunday, January 06, 2013 11:25 AM
To: n8ve...@googlegroups.com
Subject: Re: [N8VEM-S100:1282] LAVA-10 Zener Diode = 1N5226 (3.3v)


why not use 74lvxxx logic to interface to the lava board ? - it does the protection and is 5V tolerant - it has been used in propeller interfaces for the same thing and makes the parts count a lot smaller

On Sunday, January 6, 2013 11:51:09 AM UTC-6, lynchaj wrote:

Hi Paul!  Thanks!  Yes, the 3.3VDC Zener diodes are added after the 100 ohm
resistors for 5V to 3.3V level transition.  In theory you don't need them
and adding the Zeners are kind of a "belt and suspenders" approach to level
transition.  However the LAVA-10 is one expensive component so it is worth a
the extra expense to protect it.  I'd consider them optional but a worthy
investment even if not needed.

Thanks and have a nice day!

Andrew Lynch

> -----Original Message-----
> From: n8ve...@googlegroups.com [mailto:n8vem-
> s1...@googlegroups.com] On Behalf Of Paul Birkel
> Sent: Sunday, January 06, 2013 2:50 AM
> To: n8ve...@googlegroups.com
> Subject: [N8VEM-S100:1271] LAVA-10 Zener Diode = 1N5226 (3.3v)
> Is it intended that 1N5226 (3.3v) Zener diodes be used for the logic-level
> shifting circuits (with the 100 ohm resistors)?
> -----