MJE5850, MJE5851, MJE5852

www.onsemi.com

6

The Safe Operating Area figures shown in Figures 12 and 13 are

specified for these devices under the test conditions shown.

7.0

0

1.0

100

300

500

3.0

5.0

5 ms

100

ms

dc

20

7.0

0.05

10

400

5.0

2.0

10

1.0

0.2

0.1

BONDING WIRE LIMIT

THERMAL LIMIT

(SINGLE PULSE)

SECOND BREAKDOWN LIMIT

20

40

70 100

Figure 12. Maximum Forward Bias

Safe Operating Area

25

°C

Figure 13. RBSOA, Maximum Reverse Bias

Safe Operating Area

0.5

0.02

300

200

400

500

MJE5850

MJE5851

MJE5852

8.0

2.0

4.0

6.0

MJE5850

MJE5851

MJE5852

200

1 ms

Safe Operating Area Information

Forward Bias

There are two limitations on the power handling ability of

a transistor average junction temperature and second

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.

variable depending on power level. Second breakdown

pulse limits are valid for duty cycles to 10% but must be

≥ 25_C. Second breakdown limitations do

not derate the same as thermal limitations. Allowable

current at the voltages shown on Figure 12 may be found at

any case temperature by using the appropriate curve on

Figure 15.

high case temperatures, thermal limitations will reduce the

power that can be handled to values less than the limitations

imposed 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

during 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 RBSOA

characteristics.

Figure 14. Peak Reverse Base Current

Figure 15. Forward Bias Power Derating

0

40

120

160

0.6

SECOND BREAKDOWN

DERATING

1

0.8

0.4

0.2

60

100

140

80

THERMAL

DERATING

20

0

1.0

26

8

2.5

3.5

3.0

2.0

1.5

4