Title: Need Transient Noise Source for HSPICE
Post by Nobody25 on Jan 27th, 2014, 6:29am
Currently I've been using NGSPICE for all my circuit simulations. Due to a variety of factors I want to try and convert my simulations to HSPICE but there is one crucial problem holding me back.
In NGSPICE they have this nice little noise function called TRNOISE. Essentially what it is, is a function you call from your source and you get a 'noise' voltage source which injects noise into your transient simulations. This function is ESSENTIAL for me. Here's what the NGSPICE manual has on it:
Quote:4.1.7 Transient noise source
General Form:
TRNOISE (NA NT NALPHA NAMP RTSAM RTSCAPT RTSEMT)
Examples:
VNoiw 1 0 DC 0 TRNOISE( 2 0 n 0 . 5 n 0 0 ) $ w h ite
VNoi1of 1 0 DC 0 TRNOISE( 0 10 p 1 . 1 12 p ) $ 1 / f
VNoiw1of 1 0 DC 0 TRNOISE( 2 0 10 p 1 . 1 12 p ) $ w h ite and 1 / f
IALL 10 0 DC 0 t r n o i s e ( 1m 1 u 1 . 0 0 . 1m 15m 22 u 50 u ) $ wh ite , 1 / f , RTS
Transient noise is an experimental feature allowing (low frequency) transient noise injection and
analysis. See chapter 15.3.10 for a detailed description. NA is the Gaussian noise rms voltage
amplitude, NT is the time between sample values (breakpoints will be enforced on multiples of
this value). NALPHA (exponent to the frequency dependency), NAMP (rms voltage or current
amplitude) are the parameters for 1/f noise, RTSAM the random telegraph signal amplitude,
RTSCAPT the mean of the exponential distribution of the trap capture time, and RTSEMT
its emission time mean. White Gaussian, 1/f, and RTS noise may be combined into a single
statement. |
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Now I need this functionality in HSPICE. I've been looking through a few of the HSPICE manuals and I saw this in the HSPICE RF manual:
Quote:Behavioral Voltage Source (Noise Model)
You can implement a behavioral voltage noise source with an E-element. As
noise elements, these are two-terminal elements that represent a noise source
connected between two specified nodes.
Exxx n+ n- noise=’expression’
Where,
Exxxis the voltage-controlled element name, which must being with “E”,
followed by up to 1023 alphanumeric characters.
n+is the positive node.
n-is the negative node.
noise=’expression’can contain the bias, frequency, or other parameters.
Data form
Exxx n+ n- noise data=dataname
.DATA dataname
+ pname1 pname2
+ freq1 noise1
+ freq2 noise2
+ ...
.enddata
The data form defines a basicfrequency-noise table. The .DATAstatement
contains two parameters: frequency and noise to specify the noise value at
Gs() 0.001 1 10
12 –
s
0.0008
s 11010
× +
-----------------------------0.001 j0.006 – ()
s 1108
j1.8 10
10
× + × – () –
-------------------------------------------------------------------- -0.001 j0.006 + ()
s 1108
j1.8 10
10
× – × – () –
--------------------------------------------------------------------++ + × + =
232 HSPICE® User Guide: Simulation and Analysis
B-2008.09
Chapter 9: Sources and Stimuli
Voltage-Dependent Voltage Sources — E-elements
each frequency point. The unit for frequency is hertz, and the unit for noise is
V
2
/Hz. |
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This seems like what I want maybe but the manual gives no details on if the noise model fits a Gaussian curve or even if it runs in transient simulations (most of the noise material I've seen from HSPICE is exclusively for .NOISE sims).
Can anyone tell me if these two noise sources are equivalent or have any advice on what I can do? I would really appreciate it.
Thanks
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