LDO Turn ON from disable mode

[fincon]

Has anyone encountered a situation where a LDO loop is stable for current transients on its output but is unstable when it is Enabled or turned ON from disable mode.

A broad question related to this topic will be whether a feedback loop can be unstable eventhough all kinds of small signal stability test criterion like PM, load transients etc. indicate a stable loop.

Any help or insight will be appreciated..

Fincon

 

[hsodan]

We had problem with LDO turn-on stability. It was Zetex part, and power supply impedance was very low (alkaline battery). The propper capacitor value on output of ldo solved the problem (we had to increase it to 1uF from .22).
You have to recheck DS. If no luck, post ldo type, in/out data (load, input power impedance, check for ground wiring ..)