Minimum Versions: SmartSpice 4.6.5.R
The first input deck shows how a nominal 10 volt supply can be specified with a noisey characteristic to see how the rest of the circuit responds in the presence of this power supply noise.
The waveform shows both the voltage noise and the current noise on the supply line.
The second input deck shows how a seperate noise generating source can be specified and used.
The waveform shows the noisey voltage source that can be used to inject noise into a circuit and test for sensitivity or inject noise to look at substrate coupling.
Input Files
nsource.in — view contents
** Noisey Voltage source element
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VCC 8 0 DC 10 sd=300u ts=0.025ns
.tran .1n 500n
.save all(v) all(i)
.endn1_source.in — view contents
** RANDOM TRANSIENT VOLTAGE SOURCE
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VCC 8 0 DC 10 sd=300u ts=2.5ns
C1 8 9 1p
R1 9 0 1k
.TRAN 5NS 500NS
.option nomod nodeck
.measure averganoise avg v(8)
.measure tran mean1pos mean pos v(8) ; mean of the positive part of the waveform
.measure tran mean2pos mean pos v(8) from=10n to=90n
.measure tran mean1neg mean neg v(8) ; mean of the negative part of the waveform
.measure tran mean2neg mean neg v(8) from=10n to=90n
.measure tran rms1 rms v(8)
.measure tran rms2 rms v(8) from=10n to=90n
.END