power supply which point is good for digital circuit ground pour

Thread Starter

SpringRoll Wang

Joined Jan 14, 2018
2
This is for Bluetooth module, I'm not familiar with digital circuit. The power supply is simple , 5V ac -> full bridge -> CRCLC filter -> LM1117.

I know for digital it's better to pour ground for the lowest inductance. But from which point is good for reference ground?

another question I have is, for low inductance, does it have to calculated all the way to transformer, or just to the reference ground? or just the return path of signal?

Might be silly question, but thank you for helping :)
 

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Thread Starter

SpringRoll Wang

Joined Jan 14, 2018
2
To answer your silly question. It's nearly the same resistance in different point of the PCB, despite the filter will put noise into different points. But for higher frequencies, inductance will dominate it, therefore when current flows through it, it generates voltage which will mess you up, so it'll be different, it's better to pour copper on the most clean point of filter cap as reference ground.

As for pour ground on diode, don't even think about it.
 
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