• 状态 TI Thinks Resolved
  • 已锁定 已锁定
  • 个回复 1 个回复
  • 答案 1 答案
  • 名订阅用户 10 名订阅用户
  • 次查看 265 次查看
  • 用户 0 名在线用户
选项
选项
相关

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

about TUSB321 VBUS_DET PIN valid level

Super song
Part Number: TUSB321

1.VBUS_DET PIN is connected to VBUS with a 900K resistor, and there is a 95K pull-down resistor inside the TUSB321. After USB is inserted in actual measurement, VBUS_DET PIN is only 0.5V. I would like to know the VBUS_DET voltage threshold judged as USB insertion.

2.Can TUSB321 be powered by VBUS?  If VBUS is used for power supply, does it affect CC detection?  

  • 0
    TI__Guru**** 295050 points

    Hello，

    1.VBUS detect threshold voltage is Vbus *  95k/( 95k+900K). So we can calculate the Vbus detect voltage is about 0.477V, so you tested 0.5V is normal.(Vbus=5V)

    VBUS detection voltage criteria is 300mv +-5%. above 350mv will be safe.

    2.  It is not recommended to use Vbus power VDD. It' better to use separate power supply.