:: extrapolate SPICE data from PDF possible? ::

[3roomlab]

hi folks, ive been trying to pry out some spice data for a part (IRF B4019pbf).

no joy so far (even from IRF themselves hahaha look at this)
 Response Kali Naraharisetti via Email 03/10/2014 01:38 PM

Hello,
Unfortunately, we do not have spice model for the 4019pbf part. Try editing irfb4020pbf if possible.

Best Regards,

Kali
Applications Engineer
Technical Assistance Center
International Rectifier
THE POWER MANAGEMENT LEADER
www.irf.com


so thats the strangest part about being a manufacturer and have no data for a still in production part. 

when i compare 4020 and 4019. they are def not quite the same
4020 (http://ec.irf.com/v6/en/US/adirect/ir;jsessionid=702101E4B7DFB9F2AE7FAA16B7C193F2?cmd=catProductDetailFrame&productID=IRFB4020:)

4019 (http://ec.irf.com/v6/en/US/adirect/ir;jsessionid=B103DA4BCF80F1D09A7F787432DF5F24?cmd=catProductDetailFrame&productID=IRFB4019:)

so the question is, reading off the datasheet of 4020 vs 4019, what can i tweak in the SPICE model of 4020 so it becomes "approximately" a 4019? i suppose it is normal to slightly muck around these if you know what you are doing ... but im not sure how, has anyone?

the SPICE data from IRF on B4020

.SUBCKT irfb4020pbf 1 2 3
* SPICE3 MODEL WITH THERMAL RC NETWORK
**************************************
*      Model Generated by MODPEX     *
*Copyright(c) Symmetry Design Systems*
*         All Rights Reserved        *
*    UNPUBLISHED LICENSED SOFTWARE   *
*   Contains Proprietary Information *
*      Which is The Property of      *
*     SYMMETRY OR ITS LICENSORS      *
*Commercial Use or Resale Restricted *
*   by Symmetry License Agreement    *
**************************************
* Model generated on Apr 17, 06
* MODEL FORMAT: SPICE3
* Symmetry POWER MOS Model (Version 1.0)
* External Node Designations
* Node 1 -> Drain
* Node 2 -> Gate
* Node 3 -> Source
M1 9 7 8 8 MM L=100u W=100u
.MODEL MM NMOS LEVEL=1 IS=1e-32
+VTO=5.14599 LAMBDA=0 KP=17.4023
+CGSO=1.19651e-05 CGDO=1.28678e-07
RS 8 3 0.0001
D1 3 1 MD
.MODEL MD D IS=3.85651e-09 RS=0.00262485 N=1.42127 BV=200
+IBV=0.00025 EG=1.2 XTI=3.06882 TT=1e-07
+CJO=1.35158e-09 VJ=0.5 M=0.651548 FC=0.5
RDS 3 1 5e+07
RD 9 1 0.0699353
RG 2 7 8.72872
D2 4 5 MD1
* Default values used in MD1:
*   RS=0 EG=1.11 XTI=3.0 TT=0
*   BV=infinite IBV=1mA
.MODEL MD1 D IS=1e-32 N=50
+CJO=4.10287e-10 VJ=0.5 M=0.9 FC=1e-08
D3 0 5 MD2
* Default values used in MD2:
*   EG=1.11 XTI=3.0 TT=0 CJO=0
*   BV=infinite IBV=1mA
.MODEL MD2 D IS=1e-10 N=0.400004 RS=3e-06
RL 5 10 1
FI2 7 9 VFI2 -1
VFI2 4 0 0
EV16 10 0 9 7 1
CAP 11 10 4.10287e-10
FI1 7 9 VFI1 -1
VFI1 11 6 0
RCAP 6 10 1
D4 0 6 MD3
* Default values used in MD3:
*   EG=1.11 XTI=3.0 TT=0 CJO=0
*   RS=0 BV=infinite IBV=1mA
.MODEL MD3 D IS=1e-10 N=0.400004
.ENDS irfb4020pbf

*SPICE Thermal Model Subcircuit
.SUBCKT irfb4020pbft 5 1

R_RTHERM1         5 4  0.028278334
R_RTHERM2         4 3  0.365850945
R_RTHERM3         3 2  0.726399703
R_RTHERM4         2 1  0.309294278
C_CTHERM1         5 1  0.000247539
C_CTHERM2         4 1  0.00038267
C_CTHERM3         3 1  0.001894274
C_CTHERM4         2 1  0.023896336

.ENDS irfb4020pbft


many thanks in advance for any tips hints or input
( i am guessing, they are going to phase out 4019? so i am being "encouraged" to use 4020? but when checking element14, 4020 are somehow never in stock, maybe it is produced exclusively for a commercial product, but 4019 are plenty. but in any case how does one do simple tweaks to approximate a part? )

[Jay_Diddy_B]

Hi,

The parts are quite similar. The main differences are:

                   4019   vs      4020

RDS(on)       95m    vs       100m

This is within 5%. Remember RDS(on) will double between Tj 25 and Tj 100C so do not worry about the 5% difference.



Qg                13nC      vs   18nC
Qgd               4.1nC    vs   5.3nC




These are the total gate charge (Qg) , This is also a function of the gate drive voltage in the application circuit. I would not be too concerned about this.

Qgd is the Gate Drain charge. It is impacts the switching speed of the MOSFET. The lower gate charge means the lower voltage part will switch about 20% faster with the same gate current.


Breakdown Voltage

VBRDSS         150V     vs   200V

It is not normal in the SPICE model to run the parts to the VDS breakdown voltage.

This can be changed easily by editing this section of the model:

D1 3 1 MD
.MODEL MD D IS=3.85651e-09 RS=0.00262485 N=1.42127 BV=200
+IBV=0.00025 EG=1.2 XTI=3.06882 TT=1e-07
+CJO=1.35158e-09 VJ=0.5 M=0.651548 FC=0.5



Change the BV=200 to BV=150


In short, I would just use the IRFB4020 model, unmodified.

Regards,

Jay_Diddy_B