Hi, I'm looking for technical help on an L7981 voltage regulator issue. We have been using these for years in various designs with minimal issue. On a recent new prototype, I am having an issue I have never seen before, where on occasion the regulator shuts off for about 6ms and starts back up -- and of course this causes further issues on the downstream circuitry. It's as if the regulator detected an overcurrent and hiccuped, but there is no OC condition present. Oddly, this hiccup only occurs once every 4-12 hours, and I can find no cause. The design takes 12-24VDC in and outputs 5V at up to 1A. It is normally loaded at about 200mA, but loading it more does not change the behavior. Looking at both a current probe on the output, or at a voltage probe on the FB pin, there are no anomolies at all at the time of failure. I have redesigned the compensation network in a completely different way (using eDesignSuite) to see if that made a difference, but it has not. I am attaching a copy of my most recent design tweaks in eDesignSuite and a scope shot of an example of the problem. Any help is appreciated!
