Datasheet

IXYS Thyristor/Diode Module Types M##501-12io1 to M##501-18io1
Rating Report. Types M##501-12io1 and M##501-18io1 Issue 3 Page 4 of 10 March, 2008
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 mΩ.
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