What is the difference between power ground and digital ground ? What I understand is that the pgnd is the path through which the supply current discharges. Now the DGND, is the ground reference to the digital signals. How are they eventually connected ? Via a star connection ?
Another thing. If INA MCU we have 4 gnd pins which or rather how many will act as a pgnd and how many is dgnd ? Is there some logic in this ?
For eg - a signal from a gpio in an MCU will have a small current. This will travel via the gpio track into the other end and then go into the ground via ,say a and pin of that chip. So, which gnd pin will it take to discharge into the gnd plane ? If ,say that other ic is an ic with just 1 gnd pin, how can it be classed ? So, pgnd and dgnd are quite loosely used and can be interchanged. In fact many chips have just 1 ground pin. So that pin is a power ground or a digital ground ? The way I see it, it serves as both. So this is a disadvantage as well. Because any noise on the supply rail can cause a ground imbalance. Likewise with digital part can dump a lot of noise on ground.