Mosfet parallel devices

[GSarris]

Hi! I am using LTspice and i noticed the No of parallel devices parameters. What does it offer exactly? Also are there any aspects of circuit performance that can be improved by using certain amounts of parallel devices?
Thank you in advance
Georgios

 

[Junus2012]

in the analog IC design, we prefer to use a unique size transistor and we get the other sizes by connecting the unique one in parallel if we want to increase W or in series if we want to increase the length.
this will lead to better matching for the layout step and transistor channel resistance properties . for your case if your work is not IC design then I think the connection of parallel or series is in order to achieve different size transistor (different W/L)