What is the different of analog and digital process??

Hi guys,

I would like to know what is the different between analog and digital technology process? Is that if i use analog process, I can't have the digital circuitry or vise versa? What is the significant different in between them and what if in the mixed signal circuit design, which process is the best.

Thanks,
anachip.

the basic difference is that a digital ckt kows only two states of a signal '0' and '1'

while the analog works on any value

u can use both analog and digital ckt and even u can have them together

no one can say which is the best
u use which ever suites ur application

Because analog processes come often with support the explanation could be:


1. A process with have additional device like high-ohmic polyresistors, MIM-caps, isolated NMOS ...

2. A process with have in addition to standard analog devices special processing tricks to improve on analog imperfections like passive linearity, tempcos, noise ...

3. A better process control where you get tighter tolerances and matching of devices

4. Improved support to use the process like improved modelling and advanced tool feature support.


Digital devices could made with nearly any process, also pure bipolar with CML or E2L logic. Some hard cell library vendors support only specific processes. But that decision is because ther is a lot of effort to built a characterization for a process. So in some "analog" processes you miss some library offerings but that does not mean ther are unable to built gates.