topic If I'm using a mk66 part how do I wire it for only using one usb port? in Kinetis Microcontrollers

If I'm using a mk66 part how do I wire it for only using one usb port?

jeromeronne — Thu, 23 Jul 2015 15:09:27 GMT

The data sheet only mentions not using both ports:

I'm thinking tie Vreg_IN0 to Vreg_IN1

I would use the USB1 port so I have bus detect. then float USB0_DP and USB0_DM

Vreg_out would have some caps for filtering but otherwise would not be used.

Re: If I'm using a mk66 part how do I wire it for only using one usb port?

Hui_Ma — Fri, 24 Jul 2015 05:49:01 GMT

Hi,

There is a Note at K66 chapter 53 USB Voltage Regulator:

When USB is not used in the application, it is recommended to connect VREGOUT and VREG_INx together and tie to ground

through a 10kΩ resistor. Do not tie directly to ground, as this causes a latch-up risk. For systems where only one of the VREG_INx pins is ever used, it is also recommended to connect the two VREG_INx pins together.

Have a great day,
Ma Hui

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Re: If I'm using a mk66 part how do I wire it for only using one usb port?

jeromeronne — Tue, 28 Jul 2015 14:32:44 GMT

I had decided to just tie the two regulator inputs together. It is always good to get verification that design choices are correct!