Guidelines for Mixed signal Design

[skyismylimit]

I am at present doing a project in sigma delta adc (band pass) ... it consists of both analog and digital(Decimator) blocks... Now all my simulations are over in SPICE and moving towards layout... My frequency of operation in digital is 280Mhz and my library is 0.35u ... can any one help me in telling what precautions should i take so that there would not be any noise coulpling between analog and digital blocks.... ( U can be specific to my design or in general to mixed signal )

Thanks in advance...

 

[ppenday]

you can use gaurd rings around analog and digital blocks to avoid noise coupling between them

 

[Vamsi Mocherla]

Importantly, try and use different supplies and grounds for the analog and digital blocks......