M
Matteo
- Jan 1, 1970
- 0
hi all,
I calculated the frequency response of the CS and Cascode amplifiers
using the time constants method. Here they are:
CS
f = ( 2*PI*( Rs*Cgs + Rs*Cgs*(1+Av) + Rd*(Cdb+Cl)) )-1
Cascode
f = ( 2*PI*(Rs*Cgs1 + Cds1*2*Rs + Rd*(Cgd2+Cdb2*Cl) + 1/gm2*(Cdb1+Cgs2) )-1
where:
Rs = resistance of the imput signal
Rd = resistance under Vdd
Cl = load capacity
Vdd
|
Rd
|----------o Vout
--- |
Vcost--|| =
--> |
| ground
|
---
----||
| -->
Rs |
| |
Vin ground
|
ground
I calculated f using
Rs = 50ohm
Rd = 600ohm
W = 592 micron
and I obtained
CS => f = 1.98EE+08
Cascode => 2.08EE+08
and I think that's a really little difference! where did I make the mistake?
thank you very much!
I calculated the frequency response of the CS and Cascode amplifiers
using the time constants method. Here they are:
CS
f = ( 2*PI*( Rs*Cgs + Rs*Cgs*(1+Av) + Rd*(Cdb+Cl)) )-1
Cascode
f = ( 2*PI*(Rs*Cgs1 + Cds1*2*Rs + Rd*(Cgd2+Cdb2*Cl) + 1/gm2*(Cdb1+Cgs2) )-1
where:
Rs = resistance of the imput signal
Rd = resistance under Vdd
Cl = load capacity
Vdd
|
Rd
|----------o Vout
--- |
Vcost--|| =
--> |
| ground
|
---
----||
| -->
Rs |
| |
Vin ground
|
ground
I calculated f using
Rs = 50ohm
Rd = 600ohm
W = 592 micron
and I obtained
CS => f = 1.98EE+08
Cascode => 2.08EE+08
and I think that's a really little difference! where did I make the mistake?
thank you very much!