MP2494 EN abs. rating

DC-DC Power Converters
1

Hello. I am using the MP2494 in a very similar schematic to the evaluation board.
I have a problem when the board is powered with more than 12v.
Sometimes the IC will simply fail. Othertimes the pin 3 (EN) will blow up.
The board draw almost 2watts at 22v.

I have connected EN to VIN as per page 7 of the datasheet:

The MP2494 has an Enable control pin (EN). Drive EN above 1.8V to turn on the MP2494. Drive EN below .4V to turn it off. Tie EN to VIN for automatic start up.

But in the absolute “all other pins” are rated as +6.5V…
Now I am confused. What is the rating of the EN pin?
When VIN > 6.5V how can I enable automatic startup?

I’ll have to make new boards now :frowning:

Thank you in advance for your support,
Maximilian Schneider

2

Hello,
The EN pin has an absolute maximum voltage of 6.5V, but we don,t recommend this voltage for normal operation. You can use a voltage divider from Vin if you automatically want to enable the ic. The recommended EN pin voltage would be 3.3V. Usually a 100k resistor is tied between Vin and EN (as showed in the figure below) and calculate the other resistor according to the voltage at EN pin from Vin.
image
For example: If you are using 12V Vin, you can use 100k and 37.9k divider to give it to EN pin for 3.3V.

Let us know if you have more questions.

Regards,
Yash Shah