I'm having some problems with ADM8324 (complete P/N: ADM8324WCA29ARJZR7).
The IC works as expected but, once in a while, if I switch off and on very fast my power source (in particular if the power supply voltage is above 42 V), it seems like it doesn't start-up (the reset output is stuck at 0 V).
The IC supply voltage is 3.3 V and is generated from a buck converter which takes its input voltage from the power source (DC_BUS).
The IC is connected as indicated in the figure below:
To be sure that this behaviour was not related to other components' failure, I've made some tests even with the MR pin of the flip-flop disconnected from the ADM8324 (output floating, connected only to the pull-up resistor).
The result is the following:
As you can see, in the first part, the IC works correctly (no WD feed, periodic reset pulses), then, after the restart, the output is stuck at 0 V.
How this issue can be explained?
Can you put a RC circuit on Vcc and slow down the ramp rate.
If you have a fast ramp rate, some internal nodes might not have time to be in the right level and cause the part to wake up in an unwanted…
Thanks for your reply.
I put a RC circuit on VCC (R=120, C=4.7u) and it seems that this has solved the problem.
If you have a fast ramp rate, some internal nodes might not have time to be in the right level and cause the part to wake up in an unwanted state. I would recommend slowing down Vcc so that Vcc takes at least 2.5 ms to pass the 1.4V level.