ADC BASED CIRCUIT DESIGN

[shereesubahan]

What are the technical design care to be taken while using ADC in circuit?
Any special care in High speed ADC design?
How to isolate Analog Ground & Digital Ground in ADC?
Kindly guide in Schematic design & PCB design aspect.

[Paul van Avesaath]

well that is pretty situation dependend. there is not a single good answer to give.
can you tell us what chip you are planning to use? also what type of connector the analog signal is comming from? is a through hole connector or SMD, or maybe another chip in some cases..

is it a multi layer PCB you are planning? 4 layers or more? top and bottom component placement or top only?

A general good way is to see what the recommended pcb design is in the datasheet of the used IC, there should be some information about it.

With regards to the PCB keep a lot of clearance around the analog track, make sure the GND plane underneath is solid (no gaps) keep in mind what impedance is needed.

at what speeds is the analog signal running? below 1Ghz you can do pretty much whatever you want (which is purely my opnion) above there are a lot of things to consider if you need to implement it in a certain way.

as to schematic my general approach is pretty straight forward, but it really helps to design the schematics with PCB in mind. so it has flow.
you should be able to recognize your PCb layout when you look at the schematic. so place components in the order / orientation they need to be in the PCB.

good luck.. share your design so we can see how you did!

[robertferanec]

there is not a single good answer to give.

- I absolutelly agree with Paul van Avesaath. If you are not sure, try to find some info about PCB layout of the chip you are using (e.g. in datasheet or separate document), maybe try to find an evaluation board / starter kit and have a look how they did the PCB. That is what I normally do.