BF421 BF423

3

Motorola Small–Signal Transistors, FETs and Diodes Device Data

Figure 1. DC Current Gain

IC, COLLECTOR CURRENT (mA)

150

–1.0

15

TJ = +125°C

+25

°C

–55

°C

VCE = –10 Vdc

20

30

50

70

100

–2.0

–3.0

–5.0

–7.0

–10

–20

–30

–50

–80

–100

Figure 2. Capacitances

VR, REVERSE VOLTAGE (VOLTS)

–0.1

100

50

20

1.0

Ccb

10

2.0

5.0

Cib

Figure 3. Current–Gain — Bandwidth Product

IC, COLLECTOR CURRENT (mA)

–50

–20

–10

–5.0

–2.0

100

60

40

30

20

0

TJ = 25°C

VCE = –20 Vdc

–1.0

IC, COLLECTOR CURRENT (mA)

Figure 4. “On” Voltages

–1.0

0

VCE(sat) @ IC/IB = 10 mA

VBE @ VCE = –10 V

–0.8

–0.6

–0.4

–0.2

VCE, COLLECTOR–EMITTER VOLTAGE (VOLTS)

BF423

Figure 5. Active Region — Safe Operating Area

BONDING WIRE LIMITATION

SECOND BREAKDOWN

LIMITATION

BF421

100

µs

1.0 ms

TJ = 150°C

1.5 WATT THERMAL

LIMITATION @ TC = 25°C

625 mW THERMAL

LIMITATION @ TA = 25°C

–500

–5.0

–10

–20

–50

–100

–200

–0.2 –0.5 –1.0 –2.0 –5.0 –10 –20

–50 –100 –200 –500 –1000

80

–100

–50

–20

–10

–5.0

–2.0

–1.0

–100

–3.0

–5.0

–10

–20 –30

–50

–100

–200 –300

1.0 s