How to write measure command in Hspice?

[jutek]

hello

i've got one problem with .measure directive.

i do simple dc analysis as .dc vin 0 vdd 0.01 and probe xtmp parameter .probe xtmp=par('2*I(M1)/gmo(M1)')

when i use .measure dc i(m1) at=0.2 it measures M1's drain current for Vin=0.2V. I want to have it for xtmp=0.2V

How should i write the directive?

regards

 

[vikadik]

.measure hspice

Check out Avantis hspice guide.

 

[holddreams]

hspice measure

hello

i've got one problem with .measure directive.

i do simple dc analysis as .dc vin 0 vdd 0.01 and probe xtmp parameter .probe xtmp=par('2*I(M1)/gmo(M1)')

when i use .measure dc i(m1) at=0.2 it measures M1's drain current for Vin=0.2V. I want to have it for xtmp=0.2V

How should i write the directive?

regards

I seldom use .mearsure, just plot the waves and mearsure on it.

 

[jutek]

hspice find when

I seldom use .mearsure, just plot the waves and mearsure on it.

if i want to measure the values from plot, surely i would do that.
I have to measure many values and don't want to waste time on it

regards

 

[Hughes]

measure hspice

hello

i've got one problem with .measure directive.

i do simple dc analysis as .dc vin 0 vdd 0.01 and probe xtmp parameter .probe xtmp=par('2*I(M1)/gmo(M1)')

when i use .measure dc i(m1) at=0.2 it measures M1's drain current for Vin=0.2V. I want to have it for xtmp=0.2V

How should i write the directive?

regards

Measre the current and gm at 0.2V using .meas, and add another .meas statement:
.meas dc xtmp param='im1_200mV/ gmo_200m'

.meas dc im1_200m find i(m1) at=0.2
.meas dc gmo_200m find gmo(m1) at=0.2
.meas dc xtmp param='im1_200mV/ gmo_200m'

 

[jutek]

hspice find

it is enough to write .measure DC 'xtmp' PARAM='2*i(m1)/gmo(m1)'
but it's not the point

i want to measure i(m1) for xtmp=0.2 not for vin=0.2 which is a sweep variable

regards

 

[Hughes]

hspice .meas

it is enough to write .measure DC 'xtmp' PARAM='2*i(m1)/gmo(m1)'
but it's not the point

i want to measure i(m1) for xtmp=0.2 not for vin=0.2 which is a sweep variable

regards

Sorry for misunderstanding you.

You may use a current controlled current source (F element) (and a voltage source as a current meter) to amplifier the current through m1 with a gain of 0.1. Then xtmp=0.2 <==> I(F1) = gmo(m1), where F1 is the name of cccs. Now you can use find... when... function to get the result your expected.

Hope this time it works.

.meas tran xxx when I(F1) = gmo(m1)
.meas tran ixx find i(m1) at=xxx

BTW, I don't think
.measure DC 'xtmp' PARAM='2*i(m1)/gmo(m1)'
is syntax-correct for hspice.

Best regards,
Hughes.