John Larkin wrote:

On Thu, 16 Aug 2007 08:37:06 -0700, Joerg
wrote:


John Larkin wrote:


On Wed, 15 Aug 2007 08:50:38 -0700, Jim Thompson
wrote:



On Wed, 15 Aug 2007 08:38:09 -0700, John Larkin
wrote:



On Wed, 15 Aug 2007 07:11:54 -0700, Jim Thompson
wrote:



On Tue, 14 Aug 2007 23:42:47 -0700, The Phantom
wrote:



On Tue, 14 Aug 2007 09:51:38 -0700, Jim Thompson
wrote:



Quick ESR answer needed...

Typical 0.22uF ceramic in low voltage application (5V max), what ESR
might I expect?

At what frequency? That makes a big difference.



Client says 0.2 Ohms

I doubt that number, but don't have anything to base my doubt on.

What say yee all?

...Jim Thompson

If frequency makes a difference then isn't it "ESL" rather than ESR?

Application has capacitor charged to +1.8V, it is then connected (4ns
full-on connect time) thru a 1.5 Ohm "strap" to -1.8V.

In other words, over 2A peak current.

...Jim Thompson

Tricky. Assuming a 1 ns risetime, 4 volts available, only 2 nH or so
will get you into trouble. A cap and its leads will get you to about 2
nH, then there's all your wirebonds, not to mention the load itself.

Face-down ball bonded. ~0.5nH connections.



We usually parallel several caps, on a lot of copper, to supply a lot
of fast peak current, like through a gaasfet to drive an SRD or a
laser.

(Gotta get ready for a Board meeting. What a nuisance.)


John

Me, my wife and my oldest daughter ARE the board... no nuisance ;-)

...Jim Thompson


I wasn't bad: Plant tour, 10 minutes; shareholders' meeting, 5
minutes; board meeting, 35 minutes; lunch at Zuni Cafe, 1 hour.


You mean, no trek down to Gordon Biersch's in the evening?


No, too hoppy for my taste. But my attorney's office (he's a board
member) is just a couple of blocks from GB. He's in the penthouse of
the building at Mission and the Embarcadero, above Boulevard
Restaurant. We're sort of his hobby.


Ever tried their Maerzen? Just don't drive after a couple of those.


Yeah, here it is:

http://www.noehill.com/sf/landmarks/nat1979000528.asp


Nice digs! I guess his hourly rate is quite a bit higher than that of
engineers.

--
Regards, Joerg

http://www.analogconsultants.com