MJF6388 MJF6668

4

Motorola Bipolar Power Transistor Device Data

t, TIME (ms)

0.01

0.01

0.05

1

2

5

10

20

50

500

100K

0.1

0.5

0.2

1

0.2

0.1

0.05

R

θJC(t) = r(t) RθJC

R

θJC = °C/W MAX

D CURVES APPLY FOR POWER

PULSE TRAIN SHOWN

READ TIME AT t1

TJ(pk) – TC = P(pk) R

θJC(t)

P(pk)

t1

t2

DUTY CYCLE, D = t1/t2

SINGLE PULSE

Figure 5. Thermal Response

0.5

D = 0.5

0.3

0.03

0.02

0.02

100 200

3

30

0.3

300

1K

2K

5K

10K 20K

50K

3K

30K

0.2

0.1

0.05

TC, CASE TEMPERATURE (°C)

0

40

120

160

0.6

SECOND BREAKDOWN

DERATING

1

0.8

0.4

0.2

60

100

140

80

THERMAL

DERATING

20

Figure 6. Maximum 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 4 is based on TJ(pk) = l50_C; TC is

variable depending on conditions. Secondary breakdown

pulse limits are valid for duty cycles to 10% provided TJ(pk)

< 150

_C. TJ(pk) may be calculated from the data in Figure 5.

At high case temperatures, thermal limitations will reduce the

power that can be handled to values less than the limitations

imposed by secondary breakdown.

Figure 7. Typical Small–Signal Current Gain

f, FREQUENCY (kHz)

TC = 25°C

VCE = 4 Vdc

IC = 3 Adc

10,000

200

100

1000

500

300

10

30

2000

3000

5000

1

1000

50

10

5

100

500

2

20

200

20

50

f, FREQUENCY (kHz)

10,000

200

100

1000

500

10

2000

5000

1

1000

50

10

5

100

500

2

20

200

20

50

NPN

MJF6388

PNP

MJF6668

TC = 25°C

VCE = 4 VOLTS

IC = 3 AMPS

3

30

300

70

7