LM337 and AN-181

Jaer57

Member
2010-09-22 1:09 am
Hello everyone,

I'm new to posting here, but there is a wealth of knowledge I've been benefiting from here and for that I thank you. I have a LM337 design that I'm trying to do that goes off the 0-30V regulator example in AN-181 for the LM317. I've attached my schematic. Basically, I'm just trying to get a 0 to -5VDC output, and I've achieved that when there is no load. As soon as I attach a load, I get about -650mV no matter what the potentiometer is set to. Has anyone tried to implement AN-181's 0-30V regulator with a LM337?

Thanks in advance!

http://www.national.com/ds/LM/LM137.pdf
http://www.national.com/an/AN/AN-181.pdf (page 2-3)
 

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woody

Member
Paid Member
2002-01-15 12:57 am
Tyrone Ga. U.S.A.
You might look at the value of R69. Then look back at the aplication note you based this on. You will note they used a much lower resistor value to ensure the minimum
5ma current draw for a positive regulator and a 10ma current draw for a - regulator.
So first off try droping the value to ~120 ohms.