Hello, is it correct to use the following BSS138PW MOSFET configuration as a switch depending on the power supply?




The idea is to close or open the MOSFET depending on the presence of 3.3V
Let's assume that HDMI data is 3.3V

 

You may want to look into the gate voltage of your chosen MOSFET. This even if you consider a logic level MOSFET. There are switches designed around switching a HDMI signal. A simple Google of HDMI switching circuits will give you an idea of what's involved. Consider something along these lines.

Ron

 

You may want to look into the gate voltage of your chosen MOSFET. This even if you consider a logic level MOSFET. There are switches designed around switching a HDMI signal. A simple Google of HDMI switching circuits will give you an idea of what's involved. Consider something along these lines.

Ron

I forgot to put the name of the MOSFET... post updated

 

OK and this is your data sheet. Note the VGS of the MOSFET and your 3.3 V gate voltage. This is not a good idea. They make switches for what you are looking to do, I linked to one.

Ron

 

OK and this is your data sheet. Note the VGS of the MOSFET and your 3.3 V gate voltage. This is not a good idea. They make switches for what you are looking to do, I linked to one.

Ron

Thanks for the answer.
Assuming you choose a MOSFET with a lower Vgs to ensure that it turns on/off completely... would you agree that, since it is an NMOS, the voltage HDMI data at the source must be equal to or lower than that at the gate?

 

You could also likely get by using a simple reed relay as a switch. Yes, I would agree with your last.

Ron

 

You could also likely get by using a simple reed relay as a switch.

Ron

Yes, but I'm interested in understanding the reasoning behind using a MOSFET in this configuration.
Did I say it correctly in my last comment?

 

You can try what we call a Logic Level MOSFET. This is again where checking the data sheet is important. Maybe another forum member will come along and share their views. I have to run as I am having a hot water heater installed.


Ron