sir,
i am making a motor driver circuit,
it has a digital part and a analog part,
i need to design a layout.
are there any guidelines i can follow?

 

There are a few calculators for that over at EEweb to determine trace width, among others...

 

Keep the logic side both physically and electrically isolated from the analog side as well as motor section (motor driver on a different board, perhaps). There are a good number of PCB design tutorials around for mixed signal and power circuits. Decoupling capacitors will be important on both sides for noise issues.

 

IPC-2221
Lots of PCB trace width calculators based on the formula in that.. All are "guidelines" and not a guarantee.