Yes. Think about why I have drawn digital ground lines in red. Because these ground lines are noisy, spiky and dirty. Do never connect anything analogeous to these red lines! The only point where analog ground is allowed to meet digital ground is the star ground point at ADC, where analog and digital ground pins are connected to each other.

Hi Kai,

With the aid of your extremely helpfull post I now know why it is needed to separate the AGND and DGND how to lay the AGND and DGND so that it works best without GND loop and without Digital noisy currents interfering the quite and precision requiring analog section.

In your schematic shown you are using a common +5V supply for the whole circuit I mean Analog as well as digital both the sections and as you confirmer the connector finds place close to the star ground. You are using a MCP3201 12 bit SPI ADC with a single common supply for Analog and Digital sections. In some circuits I have seen for example the Evaluation boards for ADuc812 and ADuc814 they use two different power connectors for Analog and Digital section. I want to know for what precision it becomes absolutly necessary to use two separate supplies and upto what precision requirement one get away with single common supply with properly laid Vcc tracks and separate and star typle AGND and DGND planes with connector close to the star point.

Thanks & Regards,
Prahlad Purohit