MP4576 enable using VCC

May I connect the EN pin to VCC (internal regulator out) pin to enable all the time?

The functional block diagram implies this will work, however the Operational Description, Start-up and Shutdown paragraph states the reference block starts before the regulator block.

Hi Rob,
Thank you for utilizing MPS Technical Forum - we apologize for the delayed response and appreciate your patience.

The EN signal is referenced to ground, therefore, no we can not connect it to VCC. As you read in the Start-up and Shutdown section, if enable is tied to VCC and reference circuit starts before the converter, this would mean you would trigger UVLO.

Typically, EN is coupled with the input or pulled up using a +200k resistor. In this case, zener divider reference is implemented to protect to EN.