Power the USB Controller

[loicguillain]

Hi everybody,

I'm using a K64 microcontroller with a battery charger, battery and an external regulator. By consequence i don't use the usb regulator VREGIN pin and the VOUT33 pin to supply my circuit (it works very well). However, now i want to use the USB controller to communicate with a computer by USB. I was wondering how can I do to supply voltage to the USB Controller. Can I connect VOUT33 and VDD together to do this? Am i forced to use the USB regulator?

I would appreciate an help :smileyhappy:

Thanks to you.

[loicguillain]

FRDM-K64

I'm testing the USB SDA port to communicate with Tera Term and turn a led off thank to my keyboard, it works.

Now i would like to same thing with the other USB port (Shield_K64USB). Problem: Not recognized by my computer as a com port, is it normal? If yes how can i do?

Thanks a lot!

[loicguillain]

I know connecting VOUT33 and VDD (where i have my 3.3v output from my external regulator) = having 3.3v going on the usb regulator output...

[Jorge_Gonzalez]

Hello Loic Guillain:

The USB transceiver gets its power from the internal USB regulator, so you need to connect the VREGIN input to either VBUS line or VDD power and also the output capacitor on VOUT33.

Supplying the USB transceiver from the VOUT33 pin is not an option.

Regards!,
Jorge Gonzalez

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