I have a spice model for a LM137 negative voltage regulator which I obtained from a McGill website (
http://www.rcsm.ece.mcgill.ca/~rfic/EC2/SPICE_MODEL_LIB.htm). I have developed a simulation using this device as well as the standard LM117 provided by multisim to regulate a positive/negative DC source. It works well. (The model for the 137 is considerably more complex that the 117).
Now then, when I replace the DC power with a rectified AC source the simulation aborts with a timestepping error. When I switch the LM137 out, the simulation runs. adding big filter caps dosn't help.
However, ifI run the simulation with a DC source for a short while then switch out the DC and switch in the AC simultaneously then the simulation is correct.
Can anyone tell me (I'm a student not a guru) what is happening and how to fix the problem. The LM137 model is below.
* MANUFACTURERS PART NO. = LM137HVH (NATIONAL SEMICONDUCTOR)
* SUBTYPE: REGULATOR
*
* THIS FILE CONTAINS A PRE-RAD MODEL AT 27 C OF THE LM137HVH THAT WAS
* DEVELOPED UNDER THE GUIDANCE OF GREGORY M. WIERZBA AT
* MICHIGAN STATE UNIVERSITY.
*
* PLEASE NOTE THE FOLLOWING:
*
* 1) THIS MODEL IS TO BE USED FOR ROOM TEMPERATURE SIMULATIONS. THE BUILT-
* IN SPICE TEMPERATURE CORRECTIONS WILL NOT WORK.
* 2) RIPPLE REJECTION, OUTPUT IMPEDANCE, LINE TRANSIENT, AND LOAD
* TRANSIENT RESPONSE ARE MODELED BASED ON LABORATORY
* MEASUREMENTS. THE CORRELATION IS QUITE GOOD. THE SIMULATION VALUES
* ARE WITHIN THE PRODUCT SPEC LIMITS.
* 3) CURRENT LIMITING AND ADJUSTMENT CURRENT BASED ON DATA SHEET
* INFORMATION ARE MODELED ACCURATELY.
* 4) DROPOUT AND POWER UP CHARACTERISTICS HAVE NOT BEEN DEVELOPED YET
* IN THIS MODEL.
* 5) FOR FURTHER DETAILS AND THE MODEL DERIVATION, OBTAIN A COPY OF
* "CA3085, LM7805, LM7812, LM7905, LM137 MACROMODEL DEVELOPMENT" BY G. M.
* WIERZBA DATED 3/25/91.
*
*
*
.SUBCKT LM137HVH 1 2 3
* IN | |
* OUT |
* ADJ
*
VREF 12 4 DC 1.25
EREG 3 12 1 2 0.0001981
IBIAS 4 1 DC 65U
RIN 4 20 100MEG
E1 5 1 20 4 600
R1 5 6 1561
RPZ 6 11 0.01
C1 11 1 1U
E2 7 1 6 1 1
RB1 7 17 25
RB2 17 8 50
DLIMIT 17 18 DMOD
ELIMIT 18 1 POLY (1) (2,1) .24 -0.0024
DFLDBCK 17 19 DMOD
EFLDBCK 19 1 POLY(1) (2,1) 1.0611 -0.0912 0.0026 -2.5E-5
CBC 8 9 1U
RBC 9 20 1561
QPASS 20 8 1 QMOD
RBOND 20 2 0.0063
.MODEL QMOD NPN(
+ IS = 1E-16
+ BF = 500
+ NF = 1
+ VAF = 150
+ IKF = 9.9999E+13
+ ISE = 0
+ NE = 1.5
+ BR = 1
+ NR = 1
+ VAR = 9.9999E+13
+ IKR = 9.9999E+13
+ ISC = 0
+ NC = 2
+ RB = 0
+ IRB = 9.9999E+13
+ RBM = 0
+ RE = 0
+ RC = 0
+ CJE = 0
+ VJE = .75
+ MJE = .33
+ TF = 0
+ XTF = 0
+ VTF = 9.9999E+13
+ ITF = 0
+ PTF = 0
+ CJC = 0
+ VJC = .75
+ MJC = .33
+ XCJC = 1
+ TR = 0
+ CJS = 0
+ VJS = .75
+ MJS = 0
+ XTB = 0
+ EG = 1.11
+ XTI = 3
+ KF = 0
+ AF = 1
+ FC = .5
+ )
.MODEL DMOD D(
+ IS = 1E-15.9
+ RS = 0
+ N = 1
+ TT = 0
+ CJO = 0
+ VJ = 1
+ M = .5
+ EG = 1.11
+ XTI = 3
+ KF = 0
+ AF = 1
+ FC = .5
+ BV = 9.9999E+13
+ IBV = .001
+ )
.ENDS LM137HVH
*$
