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Simulation references
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Contents
Keywords:
Introduction
In this page we give a detailed description of a few common simulation tasks (e.g. power consumption evaluation in Cadence) which can be encountered during the analog design activity.
Reference documentation
Spectre ssimulator official documentation! Si impara praticamente tutto!
Attenzione pero' che e' sotto MMSIM (Multi-Mode Simulation) package!
Spectre User Guide and Spectre Reference Guide
/usr/cadence/MMSIM_10.11/doc/spectreuser/spectreuser.pdf
/usr/cadence/MMSIM_10.11/doc/spectreref/spectreref.pdf
DC operating points
MOS transistor parameters evaluated from the transistor model, typically some version of the BSIM4 model.
ADE L ⇒ Results ⇒ Print ⇒ DC Operating Points
Quali DOP vengono elencati dipende poi dal modello! I DC op. poiints piu' importanti sono:
Parameter | Description |
---|---|
betaeff | |
gds | |
gm | |
id | |
ids | |
region | |
ron | |
vds | |
vdsat | |
vgs | |
vth |
betaeff
gmoverid
etc.
Analyses overview
breve rassegna di cosa vuol dire simualre
DC, TRAN, AC etc.
Calculator | Description | OCEAN syntax example |
---|---|---|
vt | wire transient voltage | VT(“/out”) |
it | node transient current | IT(“/M1/D”) |
vf | wire AC sweep voltage | VF(“/Vin”) |
if | node AC sweep current | IF(“/C0/MINUS”) |
vdc | wire DC voltage | VDC(“/vdd_disc”) |
idc | node DC current | IDC(“/V0/PLUS”) |
vs | wire DC sweep voltage | VS(“/net012”) |
is | node DC sweep current | IS(“/R1/PLUS”) |
op | instance DC operating point | OP(“M0”,“gm”) |
opt | instance transient DC operating point | OPT(“M0”,“vth”) |
var | design variable | VAR(“Ibias”) |
mp | instance model parameter | MP(“M0”,“vtho”) |
Power consumption evaluation
How to evaluate the power consumption. A detailed Wiki page about this topic has been created, see here.
ADE simulation options
Importante! soprtattutto a livello di numerical evaluation, serve sapere che esistono dei checks su gmin, etc.
ADE L ⇒ Simulation ⇒ Options ⇒ Analog…
Node impedance simulation
How to evaluate the total impedance at a node. A detailed Wiki page about this topic has been created, see here.
PWL voltage and current sources
piecewise linear (PWL)
Vpwl (piece-wise linear) to be used in transient simulations.
Values can be also specified into a plain text file and then using a Vpwlf voltage source, which takes file values and convert them to a standard Vpwl source.
analogLib ⇒ Sources ⇒ Independent ⇒ Vpwlf
The syntax is a column of time values and a column of voltage or current values,
t0 vo t1 v1 t2 v2 ... ...
Specify the full path to the file or copy it in the same directory of the netlist
Noise analysis
Click here.