Mixing A/D power domains | Cypress Semiconductor
Mixing A/D power domains
Hi, I have separated power domains for analog and digital with a common ground on a isolated copper area where the battery plugs.
I'd like to check if in this case would be a good idea to connect a voltage divider to Vdda using an open-drain pin to ground (as seen on attached pic), since this would make the return current flow through the noisier and possibly shifted digital and battery grounds.
Is it worth connecting the bottom node to Vssa using the analog globals for the sake of signal integrity? Even though this would add around 1k resistance to ground.
Am I worrying too much? Does it make a noticeable difference?