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Simulators >> Circuit Simulators >> Information needed on "mvarsearch" feature
https://designers-guide.org/forum/YaBB.pl?num=1178805289

Message started by kiran123 on May 10^th, 2007, 6:54am

Title: Information needed on "mvarsearch" feature
Post by kiran123 on May 10^th, 2007, 6:54am

Hi Experts,

I have a doubt regarding "mvarsearch" in spectreMDL. if i give my design goal as Trise, Tfall it does a search and gives me final W's of nch and pch transistors ( from below netlist say pch_w1 & nch_w1), but with this feature as it varies the W , will it also considers other parameters like drain, source area ..etc ( i.e as,ad,ps,pd etc) accordingly to that width keeping constant length

/*************NETLIST**********************/
parameters pch_w1=0.64u
parameters nch_w1=0.58u

subckt INV Y A
M0 Y A VSS VSS nch L=1.3e-07 W=pch_w1 as=2.304e-13 ad=2.304e-13 ps=2e-06 pd=2e-06 nrd=0.280382 nrs=0.280382
M1 Y A VDD VDD pch L=1.3e-07 W=nch_w1 as=1.512e-13 ad=1.512e-13 ps=1.56e-06 pd=1.56e-06 nrd=0.427249 nrs=0.427249
ends INV
/********************************************/
if not what modification i should do in MDL to get accounted these for better accuracy

it also uses deltax in option section of mvarsearch what is this exactly suppose if i want my end serach result of transistors width as multiples of (say 5E-9 as per desing) to what value i should set it to

in the desrciption it says "numerical difference % of design variables"

can above feature is also be done using "sweep" statement using "mod" if so what is that pattern ?

Thanks & Best Regards
kiran123