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Re: RF Module Soft Power Switch for AR9x, Skyboard, 9XR-PRO

Posted: Thu Nov 15, 2018 12:27 am
by MikeB
That's true, I'm probably very close to that limit, just kept inside by the diode in the battery circuit and the voltage drop across the transistor and R6. The circuit components were chosen for the bluetooth module and 3.3V supply.
So a MOSFET with a higher Vgs would be better if the radio battery is more than around 8V.

I'll need to see what other MOSFETs I have!

Edit: The AR9X uses a IRML6401 MOSFET, with a Vgs of 12V and a low gate threshold voltage.

Mike

Re: RF Module Soft Power Switch for AR9x, Skyboard, 9XR-PRO

Posted: Thu Nov 15, 2018 1:10 am
by jhsa
I thought the Ar9x used the AO3407, well, it doesn't :)
Just checked, the ArUni uses the AO3401 which is the same but with a lower Vgs, only 12V. The 07 has a max Vgs of 20V.

You could use a zener diode to keep the gate voltage under 8V. But better to find some more suitable mosfet. If you want I can mail a couple AO3407 to you..

Thanks

João

EDIT: The AO3401 should work well, and it has a lower Vgs