Hi,

Is there any reference on floorplan for mixed signal circuit?

I am often confused by the choice of pads, the arrangement for power ring.  For example, a circuit integrating ADC, PLL, and crystal oscillator, how do I plan the power supply for pad rings?


Thanks
Yawei

Yawei,

if you use a standard pad library for your design with ESD protection, the library provider should deliver you some application note to describe the criteria of correct power pad placement. It does usually not care about supply isolation between different analog/mixed-signal and digital blocks, but it already gives some starting point.

Then you should be careful about which blocks may generate supply noise and which may be sensitive to such noise. Try to provide them, as much as allowed by your pad library, with separate power lines from separate pads.

Paul

Teddy,

- put plenty decoupling caps between VCC/VEE,

is that a typo? I think we should put decoupling caps between VCC to ground and VEE to ground.

- arround the die use digital power to connect to edge seal,

Why? Do you mean connect digital power to seal ring?

Thanks
Yawei