how can use vccs in cadence to realize an ideal input trasco

[macg84]

vccs in cadence

Hello at all,

sorry the troubele but I have a problem, i want replace the input trasconductor stage in mixer gilbert cell with two ideal elemnts vccs. I want that this vccs has a gm of 16mS. I attached two schematic, the first is the circuit with input trasconductor with NMOS, the second circuit is with vccs. In the second stage there is some problem but i don't know witch. To define a gm in vccs of 16mS, i set the parameter trasconductance equal to 16m but i don't know if is the same thing.
Thaere is other important parameter that i have to set??

Thank you very much

 

[erikl]

cadence vccs

... i want replace the input trasconductor stage in mixer gilbert cell with two ideal elemnts vccs. I want that this vccs has a gm of 16mS. ... the second circuit is with vccs. In the second stage there is some problem but i don't know witch. To define a gm in vccs of 16mS, i set the parameter trasconductance equal to 16m but i don't know if is the same thing.

I think you cannot put 2 current sources in series (because they would fight against each other :-( ). You have to put them in parallel.

 

[macg84]

vccs in cadence

Yes it'is true... thank youuuuuu

 

[macg84]

vccs cadence

Sorry but i don't understand some parameter in the vccs...i want use this generator to replace the input mosfet, this mosfet have a trasconductance of 16ms, but how do i have to choose the minimum and the maximum current in this device? What is the function of the parameter multiplier??

Thank you very much

 

[Raviprasad_K]

how i put current source in cadence

What is the function of the parameter multiplier??

Multiplier gives an controllability over gm (transconductane). With gm=16mS, for an input voltage of 1V, I = 16mA with multiplier=1 and I = 32mA with multiplier=2. You can use multiplier=1 as default.

 

[macg84]

what is vccs

Yes, thank you