Greetings everyone

So where shoul i start... I am making a course project at my univercity and im having problems with it. So here is the deal:
I've got a scheme asembled (chebyshev filter) in Orcad like this one:


Transistor models are: http://www.mosis.com/cgi-bin/cgiwrap/umosis/swp/params/ibm-035/t75w_5hpe_4lm-par...

As we can see Vt0 for P type transostor is -0.4450562V, and for N type 0.5551144 V.

Top M5 and M6 transistors are "load" and must act like resistors. Their L is 35um and W is 0.7um (100/2 ratio).

Middle transistors M3 and M4 are "ladder" and their L is 0.35um, W is 7um (20/1 ratio).

Lowest transistors M1 and M2 are "in" transistors and their L is 0.7um and W is 7um (20/2 ratio).

This is made according to the datasheet i got, iput it in atached archive as Filtrai.pdf, there is also a orcad project. Inside is a charakteristika.png picture, this is what i get in output (AC sweep, from 10Hz to 10GHz, 20pointds decade). So when i make c1 and c2 31.5pF and 30pF, i dont get the peak as i get in charakteristika.png...
Why is that? How can i meke it apear? And in pdf page 422 fig. 5 i need to get currents ~80uA but as u can see i get only in nA, how can i achieve uA?

Thank you so much for your help!

Hi,


it appears that you have forgotten to "GROUND" the node at the bottom. There is no path to ground for your current to go which is why you only have nA.

Hi Buddypoor,

it does seem to be able to provide complex poles. See the pdf. in her attachment.


cheers,
Aaron