Philips BF908R, BF908 Datasheet

DISCRETE SEMICONDUCTORS

DATA SH EET

BF908; BF908R

Dual-gate MOS-FETs

Product specification
Supersedes data of April 1995
File under Discrete Semiconductors, SC07

1996 Jul 30

Philips Semiconductors Product specification

Dual-gate MOS-FETs BF908; BF908R

FEATURES

• High forward transfer admittance

• Short channel transistor with high forward transfer

admittance to input capacitance ratio

• Low noise gain controlled amplifier up to 1 GHz.

APPLICATIONS

• VHF and UHF applications with 12 V supply voltage,
such as television tuners and professional
communications equipment.

DESCRIPTION

Depletion type field-effect transistor in a plastic
microminiature SOT143 or SOT143R package. The
transistors are protected against excessive input voltage
surges by integrated back-to-back diodes between gates
and source.

CAUTION

The device is supplied in an antistatic package. The
gate-source input must be protected against static
discharge during transport or handling.

handbook, halfpage

Top view

Fig.1 Simplified outline (SOT143) and

handbook, halfpage

43

21

symbol; BF908.

34

MAM039

g
g

d

g

2

g

1

s,b

d

2

1

PINNING

PIN SYMBOL DESCRIPTION

Top view

12

MAM040

s,b

1 s, b source
2 d drain
3g
4g

2
1

gate 2
gate 1

Fig.2 Simplified outline (SOT143R) and

symbol; BF908R.

QUICK REFERENCE DATA

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

V

DS

I

D

P

tot

T

j

 forward transfer admittance 36 43 50 mS

y

fs

C

ig1-s

C

rs

drain-source voltage −−12 V
drain current −−40 mA
total power dissipation −−200 mW
operating junction temperature −−150 °C

input capacitance at gate 1 2.4 3.1 4 pF
reverse transfer capacitance f = 1 MHz 20 30 45 pF

F noise figure f = 800 MHz − 1.5 2.5 dB

1996 Jul 30 2

Philips Semiconductors Product specification

Dual-gate MOS-FETs BF908; BF908R

LIMITING VALUES

In accordance with the Absolute Maximum Rating System (IEC 134).

SYMBOL PARAMETER CONDITIONS MIN. MAX. UNIT

V

DS

I

D

±I

G1

±I

G2

P

tot

T

stg

T

j

Note

1. Device mounted on a printed-circuit board.

drain-source voltage − 12 V
drain current − 40 mA
gate 1 current − 10 mA
gate 2 current − 10 mA
total power dissipation see Fig.3; note 1

BF908 up to T
BF908R up to T

=50°C − 200 mW

amb

=40°C − 200 mW

amb

storage temperature −65 +150 °C
operating junction temperature − 150 °C

250

handbook, halfpage

P

tot

(mW)

200

150

100

50

0

0 50 100 150 200

BF908

BF908R

T

Fig.3 Power derating curves.

amb

MRC275

o

( C)

1996 Jul 30 3