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 5 of 10 September, 2014
8.3 D.C. Thermal Impedance Calculation













np
p
t
pt
p
err
1
1

Where p = 1 to n and:
n
=
number of terms in the series
t
=
Duration of heating pulse in seconds
r
t
=
Thermal resistance at time t
r
p
=
Amplitude of p
th
term

p
=
Time Constant of r
th
term
The coefficients for this device are shown in the table below:
D.C.
Term
1
2
3
4
5
r
p
1.37×10
-3
4.86×10
-3
0.0114
0.0223
0.0221

p
7.6×10
-4
8.6×10
-3
0.101
0.56
3.12
9.0 Reverse recovery ratings
(i) Q
ra
is based on 50% I
RM
chord as shown in Fig. 1
Fig. 1
(ii) Q
rr
is based on a 150 µs integration time i.e.


s
rrrr
dtiQ
 150
0
.
(iii)
2
1
t
t
FactorK 