Author Topic: Connection of Analog and Digial ground  (Read 266 times)

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Offline gogoman

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Connection of Analog and Digial ground
« on: August 29, 2020, 04:54:21 pm »
hello In what instance should a ADC analog ground and digital ground be connected with a ferrite bead. What is the criteria for the bead selection.  the current < 10mA.

thanks
 

Offline capt bullshot

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Re: Connection of Analog and Digial ground
« Reply #1 on: August 29, 2020, 06:10:30 pm »
Depends on your design constrains.
Most ADC work best when their analog and digital GND pins are tied to the very same GND plane. So no ferrite bead at all.
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Online KT88

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Re: Connection of Analog and Digial ground
« Reply #2 on: August 29, 2020, 06:53:25 pm »
Quote
In what instance should a ADC analog ground and digital ground be connected with a ferrite bead
Never!
AGND and DGND only denote the internal connections to the IC. Sharing supply currents of analog and digital sections over one bond wire would severely degrade the specs of the converter.
However it makes sense to partition the PCB into an analog and a digital area to avoid interferences between analog and digital signals.
 


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