MJF122 MJF127

3

Motorola Bipolar Power Transistor Device Data

0

80

60

40

20

4

3

2

1

TA TC

0

Figure 3. Maximum Power Derating

T, TEMPERATURE (

°C)

40

60

100

120

160

80

140

TC

20

t, TIME (ms)

0.01

0.1

0.5

10

20

50

100

200

500

5K

10K

1

5

2

1

0.2

0.1

0.05

SINGLE PULSE

R

θJC(t) = r(t) RθJC

TJ(pk) – TC = P(pk) R

θJC(t)

Figure 4. Thermal Response

0.5

0.3

0.03

0.02

0.2

1K

2K

30

300

3

0.3

3K

TA

VCE, COLLECTOR–EMITTER VOLTAGE (VOLTS)

Figure 5. Maximum Forward Bias

Safe Operating Area

1

10

1

30

CURRENT LIMIT

SECONDARY BREAKDOWN

LIMIT

THERMAL LIMIT @

TC = 25°C (SINGLE PULSE)

0.1

2

3

50

3

0.3

10

0.2

dc

TJ = 150°C

1 ms

5 ms

100

µs

2

5

0.5

5

100

20

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 5 is based on TJ(pk) = 150_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 4.

At high case temperatures, thermal limitations will reduce the

power that can be handled to values less than the limitations

imposed by secondary breakdown.