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6

REV.02 20130403

BC85x Series

t, TIME (ms)

Figure 13. Thermal Response

V

Figure 14. Active Region Safe Operating Area

BONDING WIRE LIMIT

THERMAL LIMIT

SECOND BREAKDOWN LIMIT

The safe operating area curves indicate I

transistor that must be observed for reliable operation. Collector

load lines for specific circuits must fall below the limits indicated by

the applicable curve.

The data of Figure 14 is based upon T

is variable depending upon conditions. Pulse curves are valid for

duty cycles to 10% provided T

lated from the data in Figure 13. At high case or ambient

temperatures, thermal limitations will reduce the power that can

be handled to values less than the limitations imposed by the sec-

ondary breakdown.

BC558

BC557

BC556

Z

R

Z

R

D CURVES APPLY FOR POWER

PULSE TRAIN SHOWN

READ TIME AT t

1

T

DUTY CYCLE, D = t

t

1

t

2

P

(pk)

SINGLE PULSE

SINGLE PULSE

T

T

3 ms

1s

1.0

0.7

0.5

0.3

0.2

0.1

0.07

0.05

0.03

0.02

0.01

D=0.5

0.2

0.1

0.05

0.1

0.2

0.5

1.0

2.0

5.0

10

20

50

100

200

500

1.0k

2.0k

5.0k

10k

–1.0

–0.5

–10

–30 –45 –65 –100

–200

–100

–50

–10

–5.0

–2.0

DEVICE CHARACTERISTICS