Datasheet

IXYS Thyristor/Diode Module Types M##501-12io2 to M##501-18io2
Rating Report. Types M##501-12io2 and M##501-18io2 Issue 3 Page 4 of 10 September, 2014
8.0 Computer Modelling Parameters
8.1 Thyristor Dissipation Calculations
T
AVTTT
AV
rff
WrffVV
I



2
2
2
00
2
4
and:
Kj
th
AV
TTT
R
T
W



max
Where V
T0
= 0.85 V, r
T
= 0.30 m.
R
th
= Supplementary thermal impedance, see table below and
ff = Form factor, see table below.
Supplementary Thermal Impedance
Conduction Angle
30°
60°
90°
120°
180°
270°
d.c.
Square wave
0.0702
0.0685
0.0679
0.0668
0.0658
0.0637
0.0620
Sine wave
0.0677
0.0673
0.0664
0.0655
0.0650
Form Factors
Conduction Angle
30°
60°
90°
120°
180°
270°
d.c.
Square wave
3.464
2.449
2
1.732
1.414
1.149
1
Sine wave
3.98
2.778
2.22
1.879
1.57
8.2 Calculating thyristor V
T
using ABCD Coefficients
The on-state characteristic I
T
vs. V
T
, on page 6 is represented by a set of constants A, B, C, D, forming
the coefficients of the representative equation for V
T
in terms of I
T
given below:
 
TTTT
IDICIBAV  ln
The constants, derived by curve fitting software, are given below for both hot and cold characteristics. The
resulting values for V
T
agree with the true device characteristic over a current range, which is limited to
that plotted.
25°C Coefficients
125°C Coefficients
A
1.27624207
A
1.1481301
B
5.582967×10
-4
B
-0.07739233
C
2.407706×10
-4
C
1.873999×10
-4
D
-4.020685×10
-3
D
0.01475625