9 Jun
2007
9 Jun
'07
10:23 p.m.
From: Brent Hilpert <hilpert at cs.ubc.ca>
While conversing with another list member about some old components, I was
reminded of hearing somewhere that there was a nasty failure mode of
the LM309K 5V regulator (it being the (or one of the) first integrated 5V
regs) which might make it somewhat undesirable for current use.
I don't want to declare that there is such a problem - it's a vague
second-hand rumour to me - so can anyone confirm or elaborate on this?
I've never personally run across problems with them..
A 76 Moto databook indicates it has those nice things like short-circuit
protection and thermal-overload protection.. ..another device perhaps?
Hi
Many regulators could not handle significant back voltage. The problem
would often occur if the input had a small capacitor relative to the
output and there was a bleader or other load on the input source.
This was common problem with many CMOS circuits.
Another problem was input over voltage. Often if ther was a transformer
without an input filter capacitor, when the power was turned off, the
inductive spike would wipe out the regulator. It seems like negative
rail regulators were most suseptible to this.
Dwight
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