Spice3f5

BSIM1 transfer characteristics

Drain current against gate voltage for five body biases, with a BSIM1 model from a parameter extraction program.

Five 50µm/10µm NMOS transistors using the BSIM1 model (LEVEL=4), with the body biased at 0, -1, -2, -3 and -4V and 50mV across the drain. A DC sweep of the gate voltage from 0 to 5V gives the transfer curves, measured by the 0V sources V1 to V5; body bias raises the threshold voltage. The model card was written by a parameter extraction program, with every value, including LEVEL = 4.00000E+000, as a floating point number.

010µ20µ30µ40µ50µ012345sweep (V)i(v1)i(v2)i(v3)i(v4)i(v5)
Drain current against gate voltage, VBS = 0 to -4V
  • i(v1)
  • i(v2)
  • i(v3)
  • i(v4)
  • i(v5)

Output

              Test of MOS BSIM1 implementation; DC transfer curve
              DC transfer characteristic Tue Sep 29 09:06:41  2026
--------------------------------------------------------------------------------
Index	sweep        I(V1)        I(V2)        I(V3)        
--------------------------------------------------------------------------------
0	0.000000e+00	1.029691e-13	2.140597e-12	4.179260e-12	
1	1.000000e-02	1.032273e-13	2.140597e-12	4.179260e-12	
2	2.000000e-02	1.036387e-13	2.140597e-12	4.179260e-12	
3	3.000000e-02	1.041220e-13	2.140597e-12	4.179260e-12	
4	4.000000e-02	1.047426e-13	2.140597e-12	4.179260e-12	
5	5.000000e-02	1.055384e-13	2.140597e-12	4.179260e-12	
6	6.000000e-02	1.065597e-13	2.140597e-12	4.179260e-12	
7	7.000000e-02	1.078705e-13	2.140597e-12	4.179260e-12	
8	8.000000e-02	1.095526e-13	2.140597e-12	4.179260e-12	
9	9.000000e-02	1.117110e-13	2.140597e-12	4.179260e-12	
10	1.000000e-01	1.144811e-13	2.140597e-12	4.179260e-12	
11	1.100000e-01	1.180362e-13	2.140597e-12	4.179260e-12	
12	1.200000e-01	1.225983e-13	2.140597e-12	4.179260e-12	
13	1.300000e-01	1.284528e-13	2.140597e-12	4.179260e-12	
14	1.400000e-01	1.359663e-13	2.140597e-12	4.179260e-12	
15	1.500000e-01	1.456081e-13	2.140597e-12	4.179260e-12	
16	1.600000e-01	1.579815e-13	2.140597e-12	4.179260e-12	
17	1.700000e-01	1.738607e-13	2.140597e-12	4.179260e-12	
18	1.800000e-01	1.942385e-13	2.140597e-12	4.179260e-12	
19	1.900000e-01	2.203892e-13	2.140597e-12	4.179260e-12	
20	2.000000e-01	2.539490e-13	2.140597e-12	4.179260e-12	
21	2.100000e-01	2.970168e-13	2.140597e-12	4.179260e-12	
22	2.200000e-01	3.522855e-13	2.140598e-12	4.179260e-12	
23	2.300000e-01	4.232125e-13	2.140598e-12	4.179260e-12	
24	2.400000e-01	5.142336e-13	2.140599e-12	4.179260e-12	
25	2.500000e-01	6.310423e-13	2.140599e-12	4.179260e-12	
26	2.600000e-01	7.809437e-13	2.140599e-12	4.179260e-12	
27	2.700000e-01	9.733130e-13	2.140600e-12	4.179260e-12	
28	2.800000e-01	1.220183e-12	2.140601e-12	4.179260e-12	
29	2.900000e-01	1.536993e-12	2.140602e-12	4.179260e-12	
30	3.000000e-01	1.943557e-12	2.140604e-12	4.179260e-12	
31	3.100000e-01	2.465305e-12	2.140606e-12	4.179260e-12	
32	3.200000e-01	3.134867e-12	2.140609e-12	4.179260e-12	
33	3.300000e-01	3.994122e-12	2.140614e-12	4.179260e-12	
34	3.400000e-01	5.096809e-12	2.140619e-12	4.179260e-12	
35	3.500000e-01	6.511893e-12	2.140625e-12	4.179260e-12	
36	3.600000e-01	8.327877e-12	2.140634e-12	4.179260e-12	
37	3.700000e-01	1.065834e-11	2.140646e-12	4.179260e-12	
38	3.800000e-01	1.364902e-11	2.140660e-12	4.179260e-12	
39	3.900000e-01	1.748697e-11	2.140679e-12	4.179260e-12	
40	4.000000e-01	2.241219e-11	2.140704e-12	4.179260e-12	
41	4.100000e-01	2.873271e-11	2.140737e-12	4.179260e-12	
42	4.200000e-01	3.684377e-11	2.140780e-12	4.179260e-12	
43	4.300000e-01	4.725257e-11	2.140835e-12	4.179260e-12	
44	4.400000e-01	6.060995e-11	2.140908e-12	4.179260e-12	
45	4.500000e-01	7.775109e-11	2.141002e-12	4.179260e-12	
46	4.600000e-01	9.974759e-11	2.141125e-12	4.179260e-12	
47	4.700000e-01	1.279745e-10	2.141285e-12	4.179260e-12	
48	4.800000e-01	1.641959e-10	2.141494e-12	4.179260e-12	
49	4.900000e-01	2.106754e-10	2.141766e-12	4.179260e-12	
50	5.000000e-01	2.703166e-10	2.142121e-12	4.179260e-12	
51	5.100000e-01	3.468441e-10	2.142583e-12	4.179260e-12	
52	5.200000e-01	4.450354e-10	2.143186e-12	4.179260e-12	
53	5.300000e-01	5.710167e-10	2.143971e-12	4.179260e-12	
54	5.400000e-01	7.326429e-10	2.144993e-12	4.179260e-12	
55	5.500000e-01	9.399822e-10	2.146326e-12	4.179260e-12	
56	5.600000e-01	1.205936e-09	2.148063e-12	4.179260e-12	
57	5.700000e-01	1.547028e-09	2.150327e-12	4.179261e-12	
58	5.800000e-01	1.984412e-09	2.153278e-12	4.179262e-12	
59	5.900000e-01	2.545146e-09	2.157122e-12	4.179262e-12	
60	6.000000e-01	3.263814e-09	2.162133e-12	4.179262e-12	
61	6.100000e-01	4.184563e-09	2.168662e-12	4.179263e-12	
62	6.200000e-01	5.363666e-09	2.177172e-12	4.179264e-12	
63	6.300000e-01	6.872712e-09	2.188262e-12	4.179266e-12	
64	6.400000e-01	8.802551e-09	2.202713e-12	4.179267e-12	
65	6.500000e-01	1.126811e-08	2.221546e-12	4.179270e-12	
66	6.600000e-01	1.441417e-08	2.246090e-12	4.179273e-12	
67	6.700000e-01	1.842217e-08	2.278075e-12	4.179277e-12	
68	6.800000e-01	2.351791e-08	2.319757e-12	4.179283e-12	
69	6.900000e-01	2.997989e-08	2.374078e-12	4.179290e-12	
70	7.000000e-01	3.814770e-08	2.444868e-12	4.179299e-12	
71	7.100000e-01	4.842906e-08	2.537122e-12	4.179312e-12	
72	7.200000e-01	6.130390e-08	2.657345e-12	4.179329e-12	
73	7.300000e-01	7.732188e-08	2.814021e-12	4.179352e-12	
74	7.400000e-01	9.708988e-08	3.018199e-12	4.179382e-12	
... (932 more lines)

The circuit: examples/bsim1tst.cir

Test of MOS BSIM1 implementation; DC transfer curve
****************************************************************** 
MN1 13 2 0 4 NMOS L=10U W=50.0U AD=100P AS=100P PD=40U PS=40U   
MN2 23 2 0 5 NMOS L=10U W=50.0U AD=100P AS=100P PD=40U PS=40U   
MN3 33 2 0 6 NMOS L=10U W=50.0U AD=100P AS=100P PD=40U PS=40U   
MN4 43 2 0 7 NMOS L=10U W=50.0U AD=100P AS=100P PD=40U PS=40U   
MN5 53 2 0 8 NMOS L=10U W=50.0U AD=100P AS=100P PD=40U PS=40U   
VDS 3 0 0.05    
VGS 2 0 0
V1 3 13 0       
V2 3 23 0       
V3 3 33 0       
V4 3 43 0       
V5 3 53 0       
VBS1 4 0 0      
VBS2 5 0 -1
VBS3 6 0 -2     
VBS4 7 0 -3
VBS5 8 0 -4     
*************************************************************** 
.control
*.OPTIONS LIMPTS=5000 ACCT       
dc VGS 0 5 0.01
print I(V1) I(V2) I(V3) I(V4) I(V5) 
*plot I(V1) I(V2) I(V3) I(V4) I(V5) 
*.OPTIONS LIMPTS=501 ACCT       
*VGS  2  0  PWL(0 0 5 5)
*tran 0 5 0.01
*print I(V1) I(V2) I(V3) I(V4) I(V5) 
.endc
***** MODEL PARAMETERS TEMP2 ********************       
.MODEL  NMOS   NMOS     
+           LEVEL = 4.00000E+000
+             TOX = 3.00000E-002
+             VDD = 5.00000E+000
+            TEMP = 2.70000E+001
+              DL = 7.97991E-001
+              DW = 4.77402E-001
+             VFB = -1.0087E+000
+             PHI = 7.96434E-001
+              K1 = 1.31191E+000
+              K2 = 1.46640E-001
+             ETA = -1.0027E-003
+             MUZ = 5.34334E+002
+              U0 = 4.38497E-002
+              U1 = -5.7332E-002
+             X2E = -7.6911E-004
+             X3E = 7.86777E-004
+            X2MZ = 8.25434E+000
+             MUS = 5.40612E+002
+            X2MS = -1.2992E+001
+            X3MS = -9.4035E+000
+            X2U0 = 1.06821E-003
+            X2U1 = -1.9209E-002
+            X3U1 = 7.76925E-003
+            LVFB = -2.1402E-001
+            WVFB = 3.44354E-001
+             LK1 = 3.23395E-001
+             WK1 = -5.7698E-001
+             LK2 = 1.68585E-001
+             WK2 = -1.8796E-001
+            LETA = -9.4847E-003
+            WETA = 1.47316E-002
+             LU0 = 6.38105E-002
+             WU0 = -6.1053E-002
+             LU1 = 1.01174E+000
+             WU1 = 1.62706E-002
+            LX2E = 9.62411E-003
+            WX2E = -3.7951E-003
+            LX3E = 7.35448E-004
+            WX3E = -1.7796E-003
+           LX2MZ = -2.4197E+001
+           WX2MZ = 1.95696E+001
+            LMUS = 6.21401E+002
+            WMUS = -1.9190E+002
+           LX2MS = -6.4900E+001
+           WX2MS = 4.29043E+001
+           LX3MS = 1.18239E+002
+           WX3MS = -2.9747E+001
+           LX2U0 = -8.0958E-003
+           WX2U0 = 4.03379E-003
+           LX2U1 = -7.4573E-002
+           WX2U1 = 1.47520E-002
+           LX3U1 = -1.0940E-001
+           WX3U1 = -8.3353E-003
+              N0 = 1.55
+              NB = 0.09
+              ND = 0.0 
+             LN0 = 0.0 
+             WN0 = 0.0 
+             LNB = 0.0 
+             WNB = 0.0 
+             LND = 0.0 
+             WND = 0.0 
+            CGDO = 2.70000E-010
+            CGSO = 2.70000E-010
+            CGBO = 1.40000E-010
+           XPART = 1.0
+             RSH = 35.0
+              CJ = 2.75E-4     
+             CJSW = 1.90E-10   
+             JS = 1.0E-8     
+              PB = 0.7
+             PBSW = 0.8
+              MJ = 0.5 
+             MJSW = 0.33       
+             WDF = 0.0
*****                                        *****      
.END

Run it with spice bsim1tst.cir, or open it with File › Load netlist in the Qt window. The plots and output above were made by util/mkexamples.py, which runs the deck in batch mode. All examples