Hi,
My customer has ensured that this requirement is met during power-up:
Datasheet page 16: "8.4.2 Shutdown Mode .... EN pin must be set low to turn off the LM3691 during system power up and undervoltage conditions when the supply is less than 2.3 V."
This is achieved for power-up via a resistor divider on the Vin for the EN pin, also having an LP filter (27K+100nF||10K).
But at power-down, when Vin drops below 2.3V, the EN pin is still high for some 20ms more. The scope show that LM3691 stops switching at this point even with EN high.
Can something in the chip be damaged if the power-down works this way? It is a spec violation, so better to ask.
Thanks.
B.r M.A.M