what is the neccessity to seperate analog groung and digital ground?

[Surender Reddy]

what is the neccessity to seperate analog groung and digital ground on chip?
How it effects the circuit?
if it is neccessary what are the components preffered to connect analog ground and digital ground?
What are the methods for any circuit to provide efficient result?
I have read in one site that we can use ferrite beads (or) 0 ohm resistor. But how it works

 

[yadavvlsi]

Check these:
**broken link removed**

 

[cameo_2007]

A digital Ground is faster: means the digital signal arrives to its Ground state faster than an analog transition.

 

[HTA]

The fast rise and fall times of digital switsching signals cause a ground shift in the ground inductance. Thus, if the switsching current flows through the analog ground the analog circuit get a ground spike/shift. As an example you might look at the layout design rules of a fast laser driver here: https://ichaus.biz/wp4_fastlaserdriver .

Enjoy your design work!