tfabaya
Newbie level 5
noise simulation fn
I simulated a simple common source NMOS with a 1kohm resistor load with noise analysis. in spectre noise summary, i get the squared noise at 0.1mHz as
id = 53.2567 e -18
fn = 1.395 e - 3
My transistor is 144u/2u with Kf = 1e-24 and cox=4.6mF/m^2. The gm is about 4.9mS.
Id is from thermal noise = 4kt(2/3)gm(R^2) = 4k(300)(2/3)(4.9m)(1k)^2 = 54.12 e -18 which is very close to the simulation result.
fn however, is too big. i was expecting something in the nano-range too. when i computed, i was expecting about 182 n.
what is happening here? please help.
I simulated a simple common source NMOS with a 1kohm resistor load with noise analysis. in spectre noise summary, i get the squared noise at 0.1mHz as
id = 53.2567 e -18
fn = 1.395 e - 3
My transistor is 144u/2u with Kf = 1e-24 and cox=4.6mF/m^2. The gm is about 4.9mS.
Id is from thermal noise = 4kt(2/3)gm(R^2) = 4k(300)(2/3)(4.9m)(1k)^2 = 54.12 e -18 which is very close to the simulation result.
fn however, is too big. i was expecting something in the nano-range too. when i computed, i was expecting about 182 n.
what is happening here? please help.
