BUH50 Datasheet, PDF (6/10 Pages) Motorola, Inc – POWER TRANSISTOR 4 AMPERES 800 VOLTS 50 WATTS

BUH50
150
140
130
120
110
100
90
80
70
60
50
2
IC = 1 A
TYPICAL CHARACTERISTICS
350
IBoff = IC/2
VCC = 15 V
VZ = 300 V
LC = 200 µH
250
IC = 1 A
IBoff = IC/2
VCC = 15 V
VZ = 300 V
LC = 200 µH
TJ = 125°C
TJ = 25°C
IC = 2 A
4
6
8
10
hFE, FORCED GAIN
Figure 15. Inductive Fall Time
150
IC = 2 A
TJ = 125°C
TJ = 25°C
50
3
5
7
9
11
hFE, FORCED GAIN
Figure 16. Inductive Crossover Time
1
SECOND BREAKDOWN
0.8
DERATING
0.6
THERMAL DERATING
0.4
0.2
0
20 40
60
80 100 120 140 160
TC, CASE TEMPERATURE (°C)
Figure 17. Forward Power Derating
There are two limitations on the power handling ability of a
transistor: average junction temperature and second break-
down. Safe operating area curves indicate IC – VCE limits of
the transistor that must be observed for reliable operation;
i.e., the transistor must not be subjected to greater dissipa-
tion than the curves indicate. The data of Figure 20 is based
on TC = 25°C; TJ(pk) is variable depending on power level.
Second breakdown pulse limits are valid for duty cycles to
10% but must be derated when TC > 25°C. Second
breakdown limitations do not derate the same as thermal
limitations. Allowable current at the voltages shown on
Figure 20 may be found at any case temperature by using
the appropriate curve on Figure 17.
TJ(pk) may be calculated from the data in Figure 22. At any
case temperatures, thermal limitations will reduce the power
that can be handled to values less than the limitations
imposed by second breakdown. For inductive loads, high
voltage and current must be sustained simultaneously during
turn–off with the base to emitter junction reverse biased. The
safe level is specified as a reverse biased safe operating
area (Figure 21). This rating is verified under clamped
conditions so that the device is never subjected to an
avalanche mode.
6
Motorola Bipolar Power Transistor Device Data