D24V22Fx enable pin

Support Voltage regulators
1

Hi,
as the enable pin is pulled up to Vin (around 11V-13V in my case), it is probably not a good idea to drive the “En” pin directly by a micro-controller?

The micro-controller can certainly sink enough current when the pin is driven low (pullup is 270k) , but when the uC’s pin is in high impedance state the pull-up should cause a voltage of Vin at the pin, which is far beyond the ratings of the 3.3V uC.

Of course, I could connect a not-too-large resistor between En and ground, just large enough to keep the voltage on En above 1V and small enough to keep it below 3.3V. Or remove the pullup-resistor from the regulator as described in this post Disable DV24VxxF5 pull-ups on ENABLE pin?

Any hints? Kind thanks

Claus

2

Hello.

Either of those solutions sound like they should work for you. Please note that the regulator has an internal weak pull-down resistor on the EN pin, so it will be pulled down by default if you remove the on-board pull-up.

-Tony