# Need Help With the Graphs

Discussion in 'Homework Help' started by iakovos, Dec 9, 2010.

1. ### iakovos Thread Starter New Member

Jan 19, 2010
4
0
Hry people,

Need some help with the graphs below, they are all on transient analysis, that means time, could any1 here please could explain for me what do they mean? as i need this information to understand better the circuit =/

and this is some spice code:

power meter simulation:
mn 3 2 0 0 nmod w=10u l=1
mp 3 2 4 1 pmod w=20u l=1u
vdd 1 0 5
vtstp 1 4 0
.model nmod nmos(vto=1 kp=20u)
.model pmod pmos(vto=-1 kp=10u)
vin 2 0 pulse (0 5 8n 2n 2n 8n 20n)
cl 3 0 1p
fp 0 9 vtstp 0.025
rp 9 0 100k
cp 9 0 100p
.tran 1n 60n uic
.print tran v(3) v(2)
.print tran i (vtstp)
.print tran v(9)
.probe
.end

2. ### iakovos Thread Starter New Member

Jan 19, 2010
4
0
/bump!

V(9) is increasing weirdly over the time colud some1 explain why that happens?

I(vtstp) thats the current over time i think, what i see is big rises and the then huge falls, why is that happen?

last theres V(3) V(2), again voltage over time, the graphs are very different. Iam not sure but i think that, this is the source power, V(3) is more digital _|-|_ while V(2) looks analog , i guess V(2) is alternative current (AC) while V(3) is direct current (DC) ??

hellppp!!

3. ### StayatHomeElectronics AAC Fanatic!

Sep 25, 2008
1,022
70
How about drawing out the circuit that you are simulating here? And, can you explain what your inputs are for those of us that do not remember all the details of the SPICE models.