Philips BF998R, BF998 Datasheet

DISCRETE SEMICONDUCTORS

DATA SH EET

BF998; BF998R

Silicon N-channel dual-gate
MOS-FETs

Product specification
Supersedes data of April 1991
File under Discrete Semiconductors, SC07

1996 Aug 01

Philips Semiconductors Product specification

Silicon N-channel dual-gate MOS-FETs BF998; BF998R

FEATURES

• 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 with source
and substrate interconnected. 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

Marking code: MOp.

Fig.1 Simplified outline (SOT143)

handbook, halfpage

43

21

and symbol; BF998.

34

MAM039

g
g

d

g

2

g

1

s,b

d

2

1

PINNING

PIN SYMBOL DESCRIPTION

1 s, b source

Top view

Marking code: MOp.

12

MAM040

2 d drain
3g
4g

gate 2

2

gate 1

1

Fig.2 Simplified outline (SOT143R)

and symbol; BF998R.

QUICK REFERENCE DATA

SYMBOL PARAMETER CONDITIONS TYP. MAX. UNIT

V

DS

I

D

P

tot

 forward transfer admittance 24 − mS

y

fs

C

ig1-s

C

rs

drain-source voltage − 12 V
drain current − 30 mA
total power dissipation − 200 mW

input capacitance at gate 1 2.1 − pF

reverse transfer capacitance f = 1 MHz 25 − fF
F noise figure f = 800 MHz 1 − dB
T

j

operating junction temperature − 150 °C

s,b

1996 Aug 01 2

Philips Semiconductors Product specification

Silicon N-channel dual-gate MOS-FETs BF998; BF998R

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

P

tot

T

stg

T

j

Notes

1. Device mounted on a ceramic substrate, 8 mm × 10 mm × 0.7 mm.

2. Device mounted on a printed-circuit board.

drain-source voltage − 12 V
drain current − 30 mA
gate 1 current − 10 mA
gate 2 current − 10 mA
total power dissipation; BF998 up to T

up to T

total power dissipation; BF998R up to T

=60°C; see Fig.3; note 1 − 200 mW

amb

=50°C; see Fig.3; note 2 − 200 mW

amb

=50°C; see Fig.4; note 1 − 200 mW

amb

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

handbook, halfpage

200

P

tot max
(mW)

100

0

0 200100

(1) Ceramic substrate.
(2) Printed-circuit board.

(2) (1)

Fig.3 Power derating curves; BF998.

T

amb

o

( C)

MLA198

handbook, halfpage

200

P

tot max
(mW)

100

0

0 200100

Fig.4 Power derating curve; BF998R.

T

amb

MGA002

(°C)

1996 Aug 01 3

Philips Semiconductors Product specification

Silicon N-channel dual-gate MOS-FETs BF998; BF998R

THERMAL CHARACTERISTICS

SYMBOL PARAMETER CONDITIONS VALUE UNIT

R

th j-a

R

th j-a

Notes

1. Device mounted on a ceramic substrate, 8 mm × 10 mm × 0.7 mm.

2. Device mounted on a printed-circuit board.

STATIC CHARACTERISTICS

=25°C; unless otherwise specified.

T

j

SYMBOL PARAMETER CONDITIONS MIN. MAX. UNIT

±V

(BR)G1-SS

±V

(BR)G2-SS

−V

(P)G1-S

−V

(P)G2-S

I

DSS

±I

G1-SS

±I

G2-SS

thermal resistance from junction to ambient in free air; BF998 note 1 460 K/W

note 2 500 K/W

thermal resistance from junction to ambient in free air; BF998R note 1 500 K/W

gate 1-source breakdown voltage V
gate 2-source breakdown voltage V
gate 1-source cut-off voltage V
gate 2-source cut-off voltage V
drain-source current V
gate 1 cut-off current V
gate 2 cut-off current V

G2-S=VDS
G1-S=VDS
G2-S
G1-S
G2-S
G2-S=VDS
G1-S=VDS

= 0; I
= 0; I

= ±10 mA 6 20 V

G1-SS

= ±10 mA 6 20 V

G2-SS

=4V; VDS=8V; ID=20µA − 2.0 V
= 0; VDS=8V; ID=20µA − 1.5 V
=4V; VDS=8V; V

= 0; V

G1-S

= 0; V

G2-S

= 0; note 1 2 18 mA

G1-S

= ±5V − 50 nA
= ±5V − 50 nA

Note

1. Measured under pulse condition.

DYNAMIC CHARACTERISTICS

Common source; T

=25°C; VDS=8V;V

amb

= 4 V; ID= 10 mA.

G2-S

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

y

 forward transfer admittance f = 1 kHz 21 24 − mS

fs

C

ig1-s

C

ig2-s

C

os

C

rs

F noise figure f = 200 MHz; G

input capacitance at gate 1 f = 1 MHz − 2.1 2.5 pF
input capacitance at gate 2 f = 1 MHz − 1.2 − pF
output capacitance f = 1 MHz − 1.05 − pF
reverse transfer capacitance f = 1 MHz − 25 − fF

f = 800 MHz; G

= 2 mS; BS=B

S

= 3.3 mS; BS=B

S

Sopt

− 0.6 − dB

− 1.0 − dB

Sopt

1996 Aug 01 4