TUSB2077 USB Hub, Crystal only runs in Reset

SungJun Kim

I have a design that is using two TUSB2077 USB hub chips and I have same problem on two TUSB2077.

TUSB2077 chips does not work. And crystal work only during a short period of time when power-on or connected usb connector.

D + / - signals when using osciloscope I was able to confirm that four times the amount of data communication. And I got message "USB device not recognized" from my PC.

my schematic : https://skydrive.live.com/redir?resid=F38D5791557580B9!158&authkey=!AH697eXoiJkDlzM

Thank you.

over 12 years ago

0 Elias Villegas M. over 12 years ago

TI__Guru* 76130 points

Hello,

We are reviewing your question and we'l reply soon.

Regards.

0 Diego Cortes over 12 years ago in reply to Elias Villegas M.

TI__Mastermind 36085 points

Hello,

I reviewed the schematic and the TUSB2077 side seems OK, however I need to clarify more facts; can You provide me some scope captures of VCC, GND, XTALL1/2, RRESET and SUSPND?. Also I am wondering which device is enumerated as "USB device not recognized", the TUSB2077 or the device connected to It.

Regards,

Diego.