BC490,A

3

Motorola Small–Signal Transistors, FETs and Diodes Device Data

Figure 2. Current–Gain — Bandwidth Product

IC, COLLECTOR CURRENT (mA)

–200

–70

–50

–30

–20

–10

–7.0

–5.0

–3.0

–2.0

200

100

70

50

20

VCE = –2.0 V

TJ = 25°C

Figure 3. Capacitance

VR, REVERSE VOLTAGE (VOLTS)

–100

–50

–20

–10

–5.0

–2.0

–1.0

–0.5

–0.2

–0.1

100

70

50

30

20

5.0

TJ = 25°C

Cobo

Cibo

10

Figure 4. Switching Time

IC, COLLECTOR CURRENT (mA)

–500

–50

–30

–20

–10

–7.0

–5.0

1.0 k

VCC = –40 V

IC/IB = 10

IB1 = IB2

TJ = 25°C

700

500

300

200

100

70

50

30

20

10

ts

tf

tr

td @ VBE(off) = –0.5 V

–100

7.0

–200

–100

–70

–300

30

Figure 5. Thermal Response

t, TIME (ms)

1.0

0.01

0.02

0.03

0.05

0.07

0.1

0.2

0.3

0.5

0.7

1.0

2.0

5.0

10

20

50

100

200

500

1.0 k

2.0 k

5.0 k

10 k

20 k

50 k

100 k

D = 0.5

0.2

0.1

0.02

0.01

SINGLE PULSE

DUTY CYCLE, D = t1/t2

D CURVES APPLY FOR POWER

PULSE TRAIN SHOWN

READ TIME AT t1 (SEE AN–469)

TJ(pk) – TC = P(pk) Z

θJC(t)

TJ(pk) – TA = P(pk) Z

θJA(t)

t1

t2

P(pk)

Z

θJC(t) = r(t) • RθJC

Z

θJA(t) = r(t) • RθJA

SINGLE PULSE