BUF634 supply problems?
Sep 5, 2007 at 5:49 AM Thread Starter Post #1 of 19
xmokshax

xmokshax

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has anyone else been having problems sourcing BUF634 chips (both DIP-8 and SO-8 packages)? Digi-Key, Mouser, and Newark are all out of stock, and Digi-Key customer service can't even give me an estimate of when they'll be receiving more. apparently, TI hasn't supplied them with any lead time estimates. Newark actually has the chips listed as no longer available.

anyone know what the deal is? are there any other good sources for these chips? i was just gearing up to build myself a PIMETA, but if i can't get any BUF634s, i might have to pick up a different project.
 
Sep 5, 2007 at 6:36 AM Post #2 of 19
Yep, availability of BUF634P and BUP634U have been problematic for quite some time now. There had been a number of TI parts with problems (presumably due to production conversion to RoHS compliance). Most of them are now readily available again except the BUF634. Why? I don't know. I doubt that it's obsolete because there is high demand for them (not just from the DIY market which is very limited). Perhaps the production volume can't keep up with demand and some major TI customers (who buy in large enough quantities not to require going through distributors like Digi-Key or Mouser) are slurping up all the available chips. It's just a wild guess...
 
Sep 5, 2007 at 10:16 AM Post #3 of 19
I have LMH6321 in my PPAS. They sound very good. I can't see why the shouldn't go well in a PIMETA. The current draw is substantially higher though. I use AAA's instead of 9V.
 
Sep 5, 2007 at 3:42 PM Post #4 of 19
Quote:

Originally Posted by NelsonVandal /img/forum/go_quote.gif
I have LMH6321 in my PPAS. They sound very good. I can't see why the shouldn't go well in a PIMETA. The current draw is substantially higher though. I use AAA's instead of 9V.


And also you need to cut of pin 2 of LMH6321 if you use it on BUF634 position.
 
Sep 5, 2007 at 4:01 PM Post #5 of 19
so LMH6321 will sound very similar to BUF634 in this application? also, is it stackable? i was planning on using two stacked BUF634s for each output stage.

as i asked above, any leads on good suppliers of BUF634 that still have some in stock? i promise i won't clean them out... i only need six!
tongue.gif
 
Sep 5, 2007 at 6:08 PM Post #10 of 19
Quote:

Originally Posted by xmokshax /img/forum/go_quote.gif
so LMH6321 will sound very similar to BUF634 in this application? also, is it stackable? i was planning on using two stacked BUF634s for each output stage.


I don't think these should be stacked, and I can't see why either. They are very powerful. Most people who have tried both seem to think LMH6321 is superior. I've only tried LMH's and discrete buffers. I'd say the LMH's sound at least as good as the typical diamond buffers, with or without CCS.
 
Sep 5, 2007 at 6:18 PM Post #11 of 19
Quote:

Originally Posted by tomb /img/forum/go_quote.gif
The historical alternative has been Jameco. Unfortunately, they are short, too. I just checked and they have 1. More to come on 12/26/07.


Futurlec has them, although at the ridiculous price of $16.90US/each.

http://futurlec.com/cgi-bin/search/q...art_no=BUF634P
 
Sep 5, 2007 at 6:21 PM Post #12 of 19
Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif
www.partsconnexion.com has stock and they had stock last time there was a BUG634 slump, last year.


Good one! That's the solution, xmokshax!
 
Sep 5, 2007 at 7:47 PM Post #13 of 19
Quote:

Originally Posted by NelsonVandal /img/forum/go_quote.gif
I don't think these should be stacked, and I can't see why either. They are very powerful. Most people who have tried both seem to think LMH6321 is superior. I've only tried LMH's and discrete buffers. I'd say the LMH's sound at least as good as the typical diamond buffers, with or without CCS.


I agree, here is what's on the manual: "However, the maximum available
current, set by internal circuitry, is about 700 mA at room temperature. ........ If the VCL pin (Pin 2) is left open, the output short circuit current will default to about 700 mA."
 
Oct 8, 2007 at 5:52 AM Post #15 of 19
Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif
www.partsconnexion.com has stock and they had stock last time there was a BUF634 slump, last year.


They have the 'P' (DIP package), but no one seems to have the TO-220 that Broskie recommends for the 24V Aikido retrofit. Any suggestions? I'm kinda nervous about this as I've never had to worry about heatsinking in my limited diy experience.
 
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