Problem 4.25
1. Schematic
1-1. With the source-follower
1-2. Without the source-follower
2. HSPICE Netlist
2-1. With the source-follower
* Problem 4.25
* MOS model
.include p35_cmos_models_tt.inc
* main circuit
mn1 1 2 3 3 nmos L=0.35u W=100u
Cin 2 0 30f
Rin 2 0 5K
CL 3 0 8p
* current source
Ibias 3 0 1.5m
Iin 0 2 dc 200u ac 1
** Iin dc value adjusted to ensure mn1 is in active region
* voltage source
vdd 1 0 dc 3.3
* analysis
.op
.ac dec 10 1k 100G
* options
.options post
.end
2-2. Without the source-follower
* Problem 4.25 without the sourece-follower
* MOS model
.include p35_cmos_models_tt.inc
* main circuit
Cin 2 0 30f
Rin 2 0 5K
CL 2 0 8p
* current source
Iin 0 2 dc 200u ac 1
** Iin dc value adjusted to ensure mn1 is in active region
* analysis
.op
.ac dec 10 1k 100G
* options
.options post
.end
3. Simulation Result
fT [MHz] | |
with the source follower | 228 |
without the source follower | 3.98 |