BUL44 BUL44F

5

Motorola Bipolar Power Transistor Device Data

130

120

110

100

90

80

10

11

12

13

14

15

hFE, FORCED GAIN

9.0

8.0

7.0

6.0

5.0

140

150

160

170

110

90

70

50

10

11

12

13

14

15

hFE, FORCED GAIN

9.0

8.0

7.0

6.0

5.0

130

150

170

190

0.1

1.0

10

10

100

1000

VCE, COLLECTOR–EMITTER VOLTAGE (VOLTS)

0.01

TYPICAL SWITCHING CHARACTERISTICS

(IB2 = IC/2 for all switching)

0

200

400

500

2.5

2.0

1.5

1.0

0.5

0

VCE, COLLECTOR–EMITTER VOLTAGE (VOLTS)

100

300

600

700

20

40

60

80

100

1.0

0.8

0.6

0.4

0.2

0

TC, CASE TEMPERATURE (°C)

120

140

160

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 dissipation

than the curves indicate. The data of figure 15 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 limita-

tions do not derate the same as thermal limitations. Allowable

current at the voltages shown on figure 15 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 20

and 21. At any case temperatures, thermal limitations will

reduce the power than can be handled to values less than the

limitations imposed by second breakdown. For inductive

loads, high voltage and current must be sustained simulta-

neously during turn–off with the base–to–emitter junction re-

verse–biased. The safe level is specified as a reverse–

biased safe operating area (Figure 16). This rating is verified

under clamped conditions so that the device is never

subjected to an avalanche mode.

GUARANTEED SAFE OPERATING AREA INFORMATION

Figure 13. Inductive Fall Time

Figure 14. Inductive Crossover Time

Figure 15. Forward Bias Safe Operating Area

Figure 16. Reverse Bias Switching Safe Operating Area

Figure 17. Forward Bias Power Derating

IC = 0.4 A

IC = 1 A

IB(off) = IC/2

VCC = 15 V

VZ = 300 V

LC = 200 µH

IB(off) = IC/2

VCC = 15 V

VZ = 300 V

LC = 200 µH

IC = 1 A

IC = 0.4 A

10

µs

1

µs

50

µs

1 ms

5 ms

Extended

SOA

DC (BUL44)

DC (BUL44F)

TC ≤ 125°C

GAIN

≥ 4

LC = 500 µH

–1.5 V

–5 V

0 V

SECOND BREAK–

DOWN DERATING

THERMAL DERATING

TJ = 25°C

TJ = 125°C

TJ = 25°C

TJ = 125°C