BD241B BD241C BD242B BD242C

3

Motorola Bipolar Power Transistor Device Data

Figure 4. Thermal Response

t, TIME (ms)

1.0

0.01

0.01

0.7

0.5

0.3

0.2

0.1

0.07

0.05

0.03

0.02

0.02

0.05

0.1

0.2

0.5

1.0

2.0

5.0

10

20

50

100

200

1.0 k

500

Z

θJC (t) = r(t) RθJC

R

θJC = 3.125°C/W MAX

D CURVES APPLY FOR POWER

PULSE TRAIN SHOWN

READ TIME AT t1

TJ(pk) – TC = P(pk) Z

θJC(t)

P(pk)

t1

t2

DUTY CYCLE, D = t1/t2

D = 0.5

0.2

0.05

0.02

0.01

SINGLE PULSE

0.1

SECOND BREAKDOWN

LIMITED @ TJ v 150°C

THERMAL LIMITATION @ TC = 25°C

BONDING WIRE LIMITED

CURVES APPLY BELOW

RATED VCEO

10

5.0

Figure 5. Active Region Safe Operating Area

IC, COLLECTOR CURRENT (AMP)

5.0

1.0

0.1

10

20

50

100

BD241B, BD242B

BD241C, BD242C

5.0 ms

100

µs

1.0 ms

0.2

2.0

0.5

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. Second breakdown pulse

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

v 150_C, TJ(pk) may be calculated from the data in Fig-

ure 4. At high case temperatures, thermal limitations will

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

limitations imposed by second breakdown.

3.0

0.03

Figure 6. Turn–Off Time

IC, COLLECTOR CURRENT (AMP)

tf @ VCC = 30 V

2.0

1.0

0.5

0.3

0.2

0.1

0.05

0.03

0.05 0.07 0.1

0.2

0.5

1.0

2.0

3.0

tf @ VCC = 10 V

IB1 = IB2

IC/IB = 10

ts

′ = ts – 1/8 tf

TJ = 25°C

ts

′

0.3

0.7

0.07

0.7

300

0.1

Figure 7. Capacitance

VR, REVERSE VOLTAGE (VOLTS)

30

1.0

2.0 3.0

5.0

20 30 40

10

0.2 0.3

0.5

200

100

70

50

TJ = + 25°C

Ceb

Ccb