rahdirs
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Hi all,
I need to design an amplifier of gain 20,such that the first stage is CS stage with source degeneration resistance of 50Ω.It drives a source follower whose load is 50Ω.The overall gain of CS + Source follower is to be greater than 20.
Given L=0.18um,Vdd=1.8V,Rd in CS stage can be as large as possible.
This was my approach.
As gain of source follower is always less than 1,i first decided to get gain of CS stage as 20.But i'm not getting it.
my spice code--
but i'm only getting gain of approx.1 at the drain end of CS stage.If i see output after Source follower,it would surely be less than 1.How can i get more gain ??
I need to design an amplifier of gain 20,such that the first stage is CS stage with source degeneration resistance of 50Ω.It drives a source follower whose load is 50Ω.The overall gain of CS + Source follower is to be greater than 20.
Given L=0.18um,Vdd=1.8V,Rd in CS stage can be as large as possible.
This was my approach.
As gain of source follower is always less than 1,i first decided to get gain of CS stage as 20.But i'm not getting it.
my spice code--
Code:
********* Simulation Settings - General section *********
.include "E:\Stuff\Spice\SPICE PROGRAMS\Low Power Latch Design\Reference Latch\180nominal.md"
********* Simulation Settings - Parameters and SPICE Options *********
Vdd Vdd Gnd 1.8V
VVin Vin Gnd dc 1 SIN (1 0.1 1000000) AC 0.1
*-------- Devices: SPICE.ORDER > 0 --------
RResistor_1 N_2 Gnd R=50
RResistor_2 Vdd N_1 R=5k
RResistor_3 N_3 Gnd R=50
MNMOS_1 N_1 Vin N_2 Gnd NMOS W=900n L=180n AS=810f PS=3.6u AD=810f PD=3.6u
MNMOS_2 Vdd N_1 N_3 Gnd NMOS W=900n L=180n AS=810f PS=3.6u AD=810f PD=3.6u
********* Simulation Settings - Analysis section *********
********* Simulation Settings - General section *********
.tran 0.1n 10000n
.print V(N_1),V(Vin)
********* Simulation Settings - Additional SPICE commands *********
.endbut i'm only getting gain of approx.1 at the drain end of CS stage.If i see output after Source follower,it would surely be less than 1.How can i get more gain ??
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