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Convert TL431 to TLVH431 (Pspice)

H

Hammy

Jan 1, 1970
0
What modifications are needed to convert C. Bassos TL431 Pspice model
to a TLVH431 model?

I tried the obvious switching the 2.495V to 1.24V but I get a
reference of 1.49V when I do this, it should be 1.24V.

I just bought fifty of these it would be nice to have a model for AC
simulations.

..SUBCKT TL431 7 6 11
V1 1 6 2.495
R1 6 2 15.6
C1 2 6 .5U
R2 2 3 100
C2 3 4 .08U
R3 4 6 10
G2 6 8 3 6 1.73
D1 5 8 DC
D2 7 8 DC
V4 5 6 2
G1 6 2 1 11 0.11
..MODEL DC D
+IS=13.5N RS=25M N=1.59
+ CJO=45P VJ=.75 M=.302
+ TT=50.4N BV=34V IBV=1MA
..ENDS
********

Thanks
 
H

Helmut Sennewald

Jan 1, 1970
0
Hammy said:
What modifications are needed to convert C. Bassos TL431 Pspice model
to a TLVH431 model?

I tried the obvious switching the 2.495V to 1.24V but I get a
reference of 1.49V when I do this, it should be 1.24V.

I just bought fifty of these it would be nice to have a model for AC
simulations.

.SUBCKT TL431 7 6 11
V1 1 6 2.495
R1 6 2 15.6
C1 2 6 .5U
R2 2 3 100
C2 3 4 .08U
R3 4 6 10
G2 6 8 3 6 1.73
D1 5 8 DC
D2 7 8 DC
V4 5 6 2
G1 6 2 1 11 0.11
.MODEL DC D
+IS=13.5N RS=25M N=1.59
+ CJO=45P VJ=.75 M=.302
+ TT=50.4N BV=34V IBV=1MA
.ENDS
********

Thanks


Hello

I had success sometimes in the past with the changes
in the model below, but I can't remember the details.

Helmut


..SUBCKT TLV431 7 6 11
V1 1 6 1.24
R1 6 2 15.6
C1 2 6 .5U
R2 2 3 100
C2 3 4 .08U
R3 4 6 10
G2 6 8 3 6 0.86
D1 5 8 DC
D2 7 8 DC
V4 5 6 1.2
G1 6 2 1 11 0.11
..MODEL DC D
+IS=13.5N RS=25M N=1.59
+ CJO=45P VJ=.75 M=.302
+ TT=50.4N BV=34V IBV=1MA
..ENDS
 
H

Hammy

Jan 1, 1970
0
Hello

I had success sometimes in the past with the changes
in the model below, but I can't remember the details.

Helmut


.SUBCKT TLV431 7 6 11
V1 1 6 1.24
R1 6 2 15.6
C1 2 6 .5U
R2 2 3 100
C2 3 4 .08U
R3 4 6 10
G2 6 8 3 6 0.86
D1 5 8 DC
D2 7 8 DC
V4 5 6 1.2
G1 6 2 1 11 0.11
.MODEL DC D
+IS=13.5N RS=25M N=1.59
+ CJO=45P VJ=.75 M=.302
+ TT=50.4N BV=34V IBV=1MA
.ENDS

Hello Helmut

I did some more looking and I found a model in C.Basso's second book
"Switch-Mode Power Supplies Spice Simulations and Practical Designs".
I haven't had too much of an opportunity to test it, but it does
provide the correct reference.

This is the schematic that SUBCKT TL431 refers to:

http://i36.tinypic.com/1j0aq.png

This is the .txt file

..SUBCKT TL431 a k ref
C1 7 a 1n
Q1 k 2 1 QN3904
R1 1 7 240
R2 7 a 6.6k
Q2 k 7 a QN3904 50
D1 ref k D4mod
D2 a k D2mod
V1 5 a DC=2.49
D3 a 2 D3mod
C4 k 2 43p
G2 a 2 5 ref -250u
*
..MODEL QN3904 NPN AF=1.0 BF=300 BR=7.5 CJC=3.5PF CJE=4.5PF
+ IKF=.025 IS=1.4E-14 ISE=3E-13 KF=9E-16 NE=1.5 RC=2.4
+ TF=4E-10 TR=21E-9 VAF=100 XTB=1.5
..MODEL D3mod D N=0.01
..MODEL D2mod D BV=36 CJO=4PF IS=7E-09 M=.45 N=1.3 RS=40
+ TT=6E-09 VJ=.6V
..MODEL D4mod D BV=100V CJO=4PF IS=7E-09 M=.45 N=2 RS=.8
+ TT=6E-09 VJ=.6V
*
..ENDS

He shows good agreement with most of the graphs in the TL431 data
sheet.

I just changed the reference voltage (V15) to 1.24V. There doesn't
seem to be any significant difference between the LV version and the
standard version other then the REF voltage, bias current and max
cathode voltage.

He uses this TL431 model all through his book for small signal
simulations as well as DC transient for SMPS's.

Thanks for the response.
 
H

Hammy

Jan 1, 1970
0
*******************************************
* REFERENCE
* | ANODE
* | | CATHODE
* | | |
.SUBCKT TLV431AJ 1 2 3
V1 6 7 DC 1.4V
I1 2 4 1E-3
R1 1 2 8.333E6
R2 4 2 RMOD 1.249K
R3 5 7 .2
D1 3 6 DMOD1
D2 2 3 DMOD1
D3 2 7 DMOD2
*E1 5 2 POLY(2) (4,2) (1,2) 0 710 -710
E1 5 2 VALUE = {V(4,2)*710 + V(1,2)*-710}
.MODEL RMOD RES (TC1=1.4E-5 TC2=-1E-6)
.MODEL DMOD1 D (RS=.3)
.MODEL DMOD2 D (RS=1E-6)
.ENDS TLV431AJ
*******************************************

...Jim Thompson


Thanks Jim
 
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