Convert TL431 to TLVH431 (Pspice)

"Hammy" schrieb im Newsbeitrag news: snipped-for-privacy@4ax.com...

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

• 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:

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.

• 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

...Jim Thompson

Thanks Jim