Adding a Schottky across solder jumper on Teensy4.1

paulfer

Member
Hi All,

Why can't/shouldn't I:
  • Cut the said solder jumper,
  • Then add a diode across as per my crude drawing,
Besides the Vf surely this would protect the USB port but still provide power to the board from the USB, when I am in the bushes and don't have a 5V supply handy.

dimensions_teensy41_photo2.jpg
 
Yes, adding this diode won't hurt anything and will help protect the USB host should you connect USB while you also have VIN power applied. The Teensy is good down to 3.6V, so the Vf drop won't matter. In fact it will take a bit of the load off the regulator

For complete protection, you would also include a diode from VIN to the external power source with the cathode also pointed towards VIN to prevent USB from possibly trying to back power the VIN external power source. That diode would need to be external to the Teensy, so may or may not be applicable in your case.
 
For complete protection, you would also include a diode from VIN to the external power source with the cathode also pointed towards VIN to prevent USB from possibly trying to back power the VIN external power source. That diode would need to be external to the Teensy, so may or may not be applicable in your case.
Yes good point. Diode added.
 
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