My customer use TUSB8020 in M.2 application(no 5V power) , may we know how to connect VBUS_DETECT_TMS pin?
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Per the USB specification the TUSB8020B uses VBUS_DETECT to determine if the upstream connection is powered on. If you have an embedded application, where the upstream connection will always be there, you can pull VBUS_DETECT high. You can connect it to 3.3V and adjust the 5V resistor divider (90.9K / 10K) accordingly.
You will need to know the expected ramp times of VDD33 and VDD in your system. If they ramp quickly, using a 1 uF capacitor to complete the RC circuit along with the internal pull-up resistor is sufficient for GRSTz. If the ramp times are slower, you may need to increase the size of the capacitor. Many systems use 2.2 uF. If the ramp times are extremely slow or unpredictable, then an active reset circuit is required.