USB Regulator in Host Mode

[TerryMcHenry]

I would like to run the USB on a KL25 in host mode, so I don't need the on-chip linear regulator.  If I look in the reference manual, figure 36-2, I see that the regulator powers "other modules" and then goes to an output pin.  What are these "other modules"?  The ultimate question is, I have 3.3V available so I don't need the regulator, can I leave it unconnected or is there something internal to the chip that needs to be powered by the output of the regulator?

[TerryMcHenry]

Perfect Jorge, thanks!

[Jorge_Gonzalez · Accepted solution]

Hello Terry:

The USB regulator provides power to the internal USB transceiver itself, so you cannot leave it unconnected. You may wire VREGIN to VDD in case you do not have another source, and also place the external 2.2 uF capacitor even if output voltage is not used.

Hope this helps!

Regards!,
Jorge Gonzalez

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