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Hi
I'm making an Arduino Uno friendly version of a cheap NRF24l01 3.3V adapter that you can see in the figure below.
The adapter is working perfectly.
You can see the module here
View attachment 351692
When i reverse engineer the original adapter i've noticed that the four capacitors of the voltage 3.3V regulator (AMS1117-3.3) are connected to a ground plane that is eletrically isolated from the other grounds.
The pin1 (GND) of the voltage regulator is connected to the other grounds but there is no continuity to the capacitors ground plane.
The red circle in the figure shows where the isolated GND plane is located.
I've measure a capacitance around 7u between the main GND and the isolated one. I think this value comes from the two input capacitors of the regulator.
The measured input resistance of the regulator is around 350k.
How exactly is this adapter working?
I'm making an Arduino Uno friendly version of a cheap NRF24l01 3.3V adapter that you can see in the figure below.
The adapter is working perfectly.
You can see the module here
View attachment 351692
When i reverse engineer the original adapter i've noticed that the four capacitors of the voltage 3.3V regulator (AMS1117-3.3) are connected to a ground plane that is eletrically isolated from the other grounds.
The pin1 (GND) of the voltage regulator is connected to the other grounds but there is no continuity to the capacitors ground plane.
The red circle in the figure shows where the isolated GND plane is located.
I've measure a capacitance around 7u between the main GND and the isolated one. I think this value comes from the two input capacitors of the regulator.
The measured input resistance of the regulator is around 350k.
How exactly is this adapter working?
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