USB CDC K60 virtual com problem

[josei]

I´m using USB CDC Vritural Com Example (MQX 4.1)  on a own desing borad K60. The usb enumerate correctly on a desktop PC, send and recibe data. But when I  connect a notebook the device not enumarate.

The usb schematics is:

The K60 ucontroller is powered by an external regulator

My software configuration is like:

SO: W7 64bit

RTOS: MQX 4.1.1

HW:MK60DN512ZVLQ10 - 144LQFP

Tool: CW10.6

To discard problems in the notebook drivers made a test with a frdmk64 and is listed correctly.

Someone can help me with this problem?

[cutworth · Accepted solution]

Hi Jose,

There is a major problem with your schematic. VOUT33 should be connected with 2.2uF. Otherwise there will not be stable 3.3V output on it. The internal USB transceiver relies on having 3.3V output on VOUT33 to operate correctly. Please try to add the cap.

Hao

[josei]

Thank Hao.

Im put the capacitor and work fine!!

Regards