Problem 2.14
1. Schematic
2. HSPICE Netlist
* Problem 2.14
* MOS model
.include p18_cmos_models_tt.inc
* main circuit
mn1 1 2 0 0 nmos L=0.2u W=20u
* voltage source
vdd 1 0 1.8
vgs 2 0 dc 0.613 ac 1
** vgs dc value adjusted to ensure Id is 0.5mA
* analysis
.op
.ac dec 100 1k 100G
* options
.options post
*slow version
.alter
.include p18_cmos_models_ss.inc
.param vt_shift = 0
vgs 2 0 dc 0.624 ac 1
** vgs dc value adjusted to ensure Id is 0.5mA
.end
3. Simulation Result
| Variation | fT [GHz] | ΔId [%] |
| Typical | 18.7 | 0 |
| VCox: -5% µn: -10% |
17.8 | -4.8 |
