where to place analog i/oand digital i/o

[parthi2311]

Hi all,

In our design, we have both analog and digital modules. My query is how to determine the position for analog i/o and digital i/o in the entire ring. Kindly help. Thanks in advance.

 

[mikersia]

typically an analog IO rings are separated(isolated) from digital with cross coupled diodes (for ESD purpose) due to necessity to limit a switching noise influence on analog parameters. Placement of analog IO should minimize digital noise influence, i.e. to be compact and close to sensitive analog pins. Digital IO placement have more degrees of freedom, but should follow ESD guidelines (number supply clamps/per length, ...), SSN (Simultaneous Switching Noise) control recommendations (slew rate control, proper number of supply IOs per switching buffers,...), and to be suitable for bonding into selected package.