How to write a hspice code to get in db range?

[mya]

hspice coding

I want to plot a second order integrator in db @yais and frequency in axis. The software that i am using is hspice. pls. tell me what i should write to get in db range.

 

[eejli]

hspice coding

vdb(node)

or use your plot software to do the transition.

 

[mya]

Re: hspice coding

thanks for ur reply. i cannot get the response graph in db. It 's in mag. only.

The one that i want is in mag. response graph and phase graph.


.ac dec 10 .001 10k
vin in 0 ac 1
.plot ac vdb(op1)

is it right?

Added after 3 hours 2 minutes:

Is BW of the integrater related to THD?
Is phase margin of the integrator related to THD?

when i run the hspice, the phase plot is ascending from 180 degree. the one i am using is 2nd order integrator.

 

[kienhuy]

hspice coding

vp(node) will give you the phase plot.

 

[Hughes]

hspice coding

If you want a continuous phase plot at 180 degree, you should add a option unwrap:
.option unwrap=1
.probe ac vdb(op1) vp(op1)

 

[mya]

Re: hspice coding

i can get the Bode plot. In phase plot , the graph shows that it is ascending from 180 degree. The one that i am using is non-inverting op-amp. I don't know how to interpret that graph.

Is THD related to Phase margin?