State of SMPS Enable pin when powering Photon from 3V3

Hardware
1

Hello, what is the recommended state of the Photon’s SMPS enable pin when powering it from 3.3V via the 3V3 pin; should it just be left unconnected?

Thanks - Andrew

2

@am_sewi, according to the datasheet, the EN pin should not be left floating. However, this only applies when the SMPS is powered. So if you are powering directly via the 3V3 pin with NO voltage on Vin or Vusb then SMPS enable can be left unconnected. The pin comes in handy when you are powering via Vin or Vusb and you want to turn off ALL power to the Photon via external circuitry. :wink:

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