With both the eval-LT7809-AZ as well as our own board much like the eval board I see unexplained rising output when the chip is below room temp
The voltage will get to target voltage but it can take 20 to 50 seconds. The voltage ramps up to some value such as 15V then gradual does jumps up (and back down) several volts over many seconds
If I warm the LT7809 mildly to just above 25C room temp everything works well including expected slow start ramp of 20msec.
I have used the eval board and our own board on-board voltage source for EXTVCC or use chip internal reference, both seem to have same issue. This is AFTER the choice of voltage to use for bias and may be some internal chip reference.
If I cool down the chip or even have it start up first time in the morning where room temp is 20C or lower I can see unexpected output rise.
This is on the eval board as well as our own board.. In both the eval and our own board this happens.
The chip has code B61779 in both cases.
Is this a known issue with next rev chip planning to look at this or is thing new and unknown issue to your team?
