Hi, I want to simulate effects of serial "spread" of small signal and power transistors in an amplifier circuit in LTSpice.
The transistors are BC550 / BC560 and MJ15003 / MJ15004.
Which of the spice parameters of these should I vary to which degree to mimick realistic differences of unmatched devices? hFE (BF) is pretty clear, somewhere I found a pointer that IS is related to Vbc, but I have no clue how much to change, if at all correct.
Any advice?
Thanks,
Mo
The models I am using are
.MODEL MJ15003 npn
+IS=1e-09 BF=226.431 NF=0.85 VAF=43.4348
+IKF=10 ISE=1e-08 NE=1.79698 BR=1.65466
+NR=1.5 VAR=434.348 IKR=4.42319 ISC=5.49997e-09
+NC=3.18751 RB=43.922 IRB=0.1 RBM=0.1
+RE=0.0001 RC=0.20765 XTB=0.746102 XTI=1
+EG=1.05 CJE=9.62276e-08 VJE=0.505131 MJE=0.650363
+TF=9.99972e-09 XTF=1.35733 VTF=0.996711 ITF=0.999802
+CJC=1.22855e-09 VJC=0.95 MJC=0.23 XCJC=0.803115
+FC=0.638728 CJS=0 VJS=0.75 MJS=0.5
+TR=1e-07 PTF=0 KF=0 AF=1
.MODEL MJ15004 pnp
+IS=1e-09 BF=226.431 NF=0.85 VAF=43.4348
+IKF=10 ISE=1e-08 NE=1.79698 BR=1.65466
+NR=1.5 VAR=434.348 IKR=4.42319 ISC=5.49997e-09
+NC=3.18751 RB=43.922 IRB=0.1 RBM=0.1
+RE=0.0001 RC=0.20765 XTB=0.746102 XTI=1
+EG=1.05 CJE=9.99946e-08 VJE=0.4 MJE=0.658304
+TF=9.99976e-09 XTF=1.3573 VTF=0.996475 ITF=0.99985
+CJC=1.22854e-09 VJC=0.95 MJC=0.23 XCJC=0.803124
+FC=0.761291 CJS=0 VJS=0.75 MJS=0.5
+TR=1e-07 PTF=0 KF=0 AF=1
.MODEL BC550C npn
+IS=45e-15 BF=689 VAF=162
+IKF=0.09 ISE=4600e-15 NE=2 NF=0.9965
+RB=167 RC=1 RE=0.04
+CJE=18.7e-12 MJE=0.35 VJE=0.75
+CJC=6.2e-12 MJC=0.25 VJC=0.4 FC=0.5
+TF=595e-12 XTF=10 VTF=10 ITF=1
+TR=10e-9 BR=12.2 IKR=0.34
+EG=1.2 XTB=1.65 XTI=3 NC=0.996
+NR=1.0 VAR=120 IRB=7e-5 RBM=1.1
+XCJC=0.6
+ISC=5e-15 mfg=CA030111
.MODEL BC560C pnp
+IS=60e-15 BF=900 VAF=160
+IKF=0.10 ISE=70e-15 NE=1.42 NF=1
+RB=170 RC=1.0 RE=0.05
+CJE=19e-12 MJE=0.3 VJE=0.75
+CJC=3.9e-12 MJC=0.3 VJC=0.75 FC=0.5
+TF=600e-12 XTF=7 VTF=4 ITF=0.45
+TR=10e-9 BR=3 IKR=0
+EG=1.1 XTB=1.5 XTI=3 NC=2
+ISC=0 mfg=CA030211
The transistors are BC550 / BC560 and MJ15003 / MJ15004.
Which of the spice parameters of these should I vary to which degree to mimick realistic differences of unmatched devices? hFE (BF) is pretty clear, somewhere I found a pointer that IS is related to Vbc, but I have no clue how much to change, if at all correct.
Any advice?
Thanks,
Mo
The models I am using are
.MODEL MJ15003 npn
+IS=1e-09 BF=226.431 NF=0.85 VAF=43.4348
+IKF=10 ISE=1e-08 NE=1.79698 BR=1.65466
+NR=1.5 VAR=434.348 IKR=4.42319 ISC=5.49997e-09
+NC=3.18751 RB=43.922 IRB=0.1 RBM=0.1
+RE=0.0001 RC=0.20765 XTB=0.746102 XTI=1
+EG=1.05 CJE=9.62276e-08 VJE=0.505131 MJE=0.650363
+TF=9.99972e-09 XTF=1.35733 VTF=0.996711 ITF=0.999802
+CJC=1.22855e-09 VJC=0.95 MJC=0.23 XCJC=0.803115
+FC=0.638728 CJS=0 VJS=0.75 MJS=0.5
+TR=1e-07 PTF=0 KF=0 AF=1
.MODEL MJ15004 pnp
+IS=1e-09 BF=226.431 NF=0.85 VAF=43.4348
+IKF=10 ISE=1e-08 NE=1.79698 BR=1.65466
+NR=1.5 VAR=434.348 IKR=4.42319 ISC=5.49997e-09
+NC=3.18751 RB=43.922 IRB=0.1 RBM=0.1
+RE=0.0001 RC=0.20765 XTB=0.746102 XTI=1
+EG=1.05 CJE=9.99946e-08 VJE=0.4 MJE=0.658304
+TF=9.99976e-09 XTF=1.3573 VTF=0.996475 ITF=0.99985
+CJC=1.22854e-09 VJC=0.95 MJC=0.23 XCJC=0.803124
+FC=0.761291 CJS=0 VJS=0.75 MJS=0.5
+TR=1e-07 PTF=0 KF=0 AF=1
.MODEL BC550C npn
+IS=45e-15 BF=689 VAF=162
+IKF=0.09 ISE=4600e-15 NE=2 NF=0.9965
+RB=167 RC=1 RE=0.04
+CJE=18.7e-12 MJE=0.35 VJE=0.75
+CJC=6.2e-12 MJC=0.25 VJC=0.4 FC=0.5
+TF=595e-12 XTF=10 VTF=10 ITF=1
+TR=10e-9 BR=12.2 IKR=0.34
+EG=1.2 XTB=1.65 XTI=3 NC=0.996
+NR=1.0 VAR=120 IRB=7e-5 RBM=1.1
+XCJC=0.6
+ISC=5e-15 mfg=CA030111
.MODEL BC560C pnp
+IS=60e-15 BF=900 VAF=160
+IKF=0.10 ISE=70e-15 NE=1.42 NF=1
+RB=170 RC=1.0 RE=0.05
+CJE=19e-12 MJE=0.3 VJE=0.75
+CJC=3.9e-12 MJC=0.3 VJC=0.75 FC=0.5
+TF=600e-12 XTF=7 VTF=4 ITF=0.45
+TR=10e-9 BR=3 IKR=0
+EG=1.1 XTB=1.5 XTI=3 NC=2
+ISC=0 mfg=CA030211
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