Requires: SmartSpice & Smartview
Minimum Versions: SMARTSPICE 4.18.16.R
The benefits of this example are that the user can perform further analysis on saved results without having to re-execute a lengthy simulation. The
example demonstrates this by performing Timing Jitter analysis on a previously executed simulation run.
Referring to the
schematic,
a transient analysis is performed by sourcing and running a simulation on the main “ex1_long.in”
inputdeck. The voltage waveforms at node 3 and 4 are saved in the “ex1_long.raw” simulation results file captured during
the transient analysis.
Separately, the “Clock_jitter_meas.in”
controldeck is sourced. The control section loads the “ex1_long.raw” simulation results file and performs a Timing Jitter
calculation
on the voltage information collected at node 3 during the previous simulation run. Furthermore, all Timing Jitter analysis jitter
vectors
are also generated (the .MEASURE … JITTER statement).
The
waveforms
show all Timing Jitter analysis metrics versus time at node 3.
The
histograms
show all Timing Jitter analysis distributions at node 3.
Graphics





Input Files
ex1_long.in
* Bipolar: Long-Tail pair
***********************************
VIN 1 0 DC 0 SIN(0 0.1 5MEG) AC 1
VCC 8 0 DC 10
VEE 9 0 DC -12
RS1 1 2 1K
RS2 5 0 1K
RC1 3 8 10K
RC2 4 8 10K
RBIAS 7 8 20K
CLOAD 3 4 5PF
Q1 3 2 6 QNL
Q2 4 5 6 QNL
Q3 6 7 9 QNL
Q4 7 7 9 QNL
.MODEL QNL NPN(BF=80 RB=100 CCS=2PF TF=0.3NS TR=6NS CJE=3PF CJC=2PF VA=50)
*
**.OPTION MEASRAW=0 post keepopinfo
**.OP current 20ns
.TRAN 5NS 50000NS
.save v(3) v(4)
*
.OPTIONS ACCT=2 RELTOL=0.001 NOMOD post rawpts=300
.END
Clock_Jitter_meas.in
* Timing Jitter measurement
*
.control
load ex1_long.raw
measure Clock jitter V(3) FROM=5u TO=45u fall='1' VAL=3.8 TARG=V(3) fall='200' VAL=3.8
.endc
.end
019_jitter_sim
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