R0878LS21L
| Model | R0878LS21L |
| Description | Assymetric SCR, 1765A I(T)RMS, 1456000mA I(T), 2100V V(DRM), 1800V V(RRM), 1 Element, |
| PDF file | Total 12 pages (File size: 347K) |
| Chip Manufacturer | IXYS |
WESTCODE
Positive development in power electronics
10.0 On-State Energy per Pulse Characteristics
R0878LS16x to R0878LS21x
These curves enable rapid estimation of device dissipation to be obtained for conditions not covered by
the frequency ratings.
Let E
p
be the Energy per pulse for a given current and pulse width, in joules
Let R
th(J-Hs)
be the steady-state d.c. thermal resistance (junction to sink)
and T
SINK
be the heat sink temperature.
Then the average dissipation will be:
W
AV
=
E
P
⋅
f and T
SINK
(max .)
=
125
−
(
W
AV
⋅
R
th
(
J
−
Hs
)
)
11.0 Reverse recovery ratings
(i) Q
ra
is based on 50% I
rm
chord as shown in Fig. 1 below.
Fig. 1
(ii) Q
rr
is based on a 150µs integration time.
150
µ
s
i.e.
Q
rr
=
∫
i
0
rr
.
dt
(iii)
12.0 Reverse Recovery Loss
t
1
K Factor
=
t
2
12.1 Determination by Measurement
From waveforms of recovery current obtained from a high frequency shunt (see Note 1, Page 5) and
reverse voltage present during recovery, an instantaneous reverse recovery loss waveform must be
constructed. Let the area under this waveform be E joules per pulse. A new heat sink temperature can
then be evaluated from:
T
SINK
(
new
)
=
T
SINK
(
original
)
−
E
⋅
(
k
+
f
⋅
R
th
(
J
−
Hs
)
)
where k = 0.227 (°C/W)/s
E = Area under reverse loss waveform per pulse in joules (W.s.)
f = rated frequency Hz at the original heat sink temperature.
R
th(J-Hs)
= d.c. thermal resistance (°C/W).
Data Sheet. Types R0878LS16x to R0878LS21x Issue 1
Page 4 of 12
June, 2001
