When not to use Low ESR capacitors

Thread Starter


Joined Jan 17, 2008
Mr. Simpson, would this apply to 78xx's? Particularly a 7812?
Here is a graph of the output capacitor for a LDO voltage regulator. If the "R" is too low the regulator will be unstable.
View attachment 197768
And... when you say "unstable" do you mean a jittery performance in holding the voltage at a regulated point, or other issues? If so what kind of issues would instability cause?


Joined Mar 2, 2015
You need to consult the data sheet for the particular regulator you're using; there is no universal "correct" answer.

In the "unstable" regions, the regulator either oscillates or shows poor transient response in the presence of changing load current.