79L05 stability, output capacitance

Jan 04, 2016 49 Replies

22uF electro is *approximately* equal to 1uF tant for high frequency bypass (according to some NatSemi? data sheet). I'd just put it in to be safe or use a solid electro 5-10 times the size.

in the germanium era

but ICs could only have

you used them once! I remember your post of disgust - and thank you it saved me from making that mistake shortly after.

worse at extremes. It's a band gap- if you don't draw current from it and make it heat up it's not horrible, especially for the price.

Unfortunately the LM723, like all zener-based references, needs too much voltage (and current- something it shares with the 78xx) for many modern designs. It's also too big. The SMT version now seems to be rare- an evolutionary dead end.

We're still buying LM-whatever-it-is ovenized buried zener references in the TO-5- I think they're up to about $75 each for the top grade.

--sp

Best regards, Spehro Pefhany Amazon link for AoE 3rd Edition: http://tinyurl.com/ntrpwu8 Microchip link for 2015 Masters in Phoenix: http://tinyurl.com/l7g2k48

Suggestion: Look up the ESR of the prescribed tantalum. Use a ceramic cap but add a resistor in series with it to make it look like the tantalum.

At that price, you might as well use an LTZ1000. (I like the LM329 a lot--it's basically a non-ovenized LM399.)

Cheers

Phil Hobbs

Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net

Yes, that's the one I meant to reference.

--sp

Best regards, Spehro Pefhany Amazon link for AoE 3rd Edition: http://tinyurl.com/ntrpwu8 Microchip link for 2015 Masters in Phoenix: http://tinyurl.com/l7g2k48

I rather not because it gets a bit hot in there and neither electrolytic nor tantalum would live very long.

Regards, Joerg http://www.analogconsultants.com/

That's exactly what I 've done last week :-)

Regards, Joerg http://www.analogconsultants.com/

Oops! Sorry. I should have read the complete thread.

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