MJ13333

6

Motorola Bipolar Power Transistor Device Data

0.005

Figure 12. Forward Bias Safe Operating Area

6

VCE, COLLECTOR–EMITTER VOLTAGE (VOLTS)

10

50

50

10

2

1

5

0.2

450

20

100

Figure 13. RBSOA, Reverse Bias Switching

Safe Operating Area

VCE, COLLECTOR–EMITTER VOLTAGE (VOLTS)

0

100

200

16

8.0

20

300

IC/IB ≥ 5

VBE(off) = 5 V

TJ = 100°C

0.05

200

350

12

4.0

0.1

0.02

400

500

dc

1 ms

10

µs

100

µs

400 500

600

600

20

0.01

MJ13333

BONDING WIRE LIMIT

THERMAL LIMIT @ TC = 25°C

(SINGLE PULSE)

SECOND BREAKDOWN LIMIT

SAFE OPERATING AREA INFORMATION

FORWARD BIAS

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 12 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 der-

ate the same as thermal limitations. Allowable current at the

voltages shown on Figure 12 may be found at any case tem-

perature by using the appropriate curve on Figure 14.

TJ(pk) may be calculated from the data in Figure 11. At high

case temperatures, thermal limitations will reduce the power

that can be handled to values less than the limitations im-

posed by second breakdown.

REVERSE BIAS

For inductive loads, high voltage and high current must be

sustained simultaneously during turn–off, in most cases, with

the base to emitter junction reverse biased. Under these

conditions the collector voltage must be held to a safe level

at or below a specific value of collector current. This can be

accomplished by several means such as active clamping,

RC snubbing, load line shaping, etc. The safe level for these

devices is specified as Reverse Bias Safe Operating Area

and represents the voltage–current condition allowable dur-

ing reverse biased turn–off. This rating is verified under

clamped conditions so that the device is never subjected to

an avalanche mode. Figure 13 gives the complete RBSOA

characteristics.

0

Figure 14. Power Derating

TC, CASE TEMPERATURE (°C)

0

40

80

80

40

100

120

160

200

60

20

THERMAL

DERATING

FORWARD BIAS

SECOND BREAKDOWN

DERATING