BF998...
Silicon N_Channel MOSFET Tetrode
•
Short-channel transistor
with high S / C quality factor
•
For low-noise, gain-controlled
input stage up to 1 GHz
ESD
:
E
lectro
s
tatic
d
ischarge sensitive device, observe handling precaution!
Type
Package
Pin Configuration
Marking
BF998
BF998R
BF998W
SOT143
SOT143R
SOT343
1=S
1=D
1=D
2=D
2=S
2=S
3=G2
3=G1
3=G1
4=G1
4=G2
4=G2
-
-
-
-
-
-
MOs
MRs
MR
Maximum Ratings
Parameter
Drain-source voltage
Continuous drain current
Gate 1/ gate 2-source current
Total power dissipation
T
S
≤
76 °C, BF998, BF998R
T
S
≤
94 °C, BF998W
Storage temperature
Channel temperature
Thermal Resistance
Parameter
Channel - soldering point
1)
BF998, BF998R
BF998W
1For calculation of
R
thJA
please refer to Application Note Thermal Resistance
Symbol
V
DS
I
D
±I
G1/2SM
P
tot
Value
12
30
10
200
200
Unit
V
mA
T
stg
T
ch
Symbol
R
thchs
-55 ... 150
150
°C
Value
≤
370
≤
280
Unit
K/W
1
Feb-13-2004
BF998...
Electrical Characteristics
Parameter
DC Characteristics
Drain-source breakdown voltage
I
D
= 10 µA,
V
G1S
= -4 V,
V
G2S
= -4 V
Gate 1 source breakdown voltage
±I
G2S
= 10 mA,
V
G2S
=
V
DS
= 0
Gate2 source breakdown voltage
±I
G2S
= 10 mA,
V
G2S
=
V
DS
= 0
Gate 1 source leakage current
±V
G1S
= 5 V,
V
G2S
=
V
DS
= 0
Gate 2 source leakage current
±V
G2S
= 5 V,
V
G2S
=
V
DS
= 0
Drain current
V
DS
= 8 V,
V
G1S
= 0 ,
V
G2S
= 4 V
Gate 1 source pinch-off voltage
V
DS
= 8 V,
V
G2S
= 4 V,
I
D
= 20 µA
Gate 2 source pinch-off voltage
V
DS
= 8 V,
V
G1S
= 0 ,
I
D
= 20 µA
-V
G2S(p)
-
0.8
2
-V
G1S(p)
-
0.8
2.5
V
I
DSS
5
9
15
mA
±I
G2SS
-
-
50
nA
±I
G1SS
-
-
50
nA
±V
(BR)G2SS
8
-
12
±V
(BR)G1SS
8
-
12
V
(BR)DS
12
-
-
V
Symbol
min.
Values
typ.
max.
Unit
2
Feb-13-2004
BF998...
Electrical Characteristics
Parameter
AC Characteristics
Forward transconductance
V
DS
= 8 V,
I
D
= 10 mA,
V
G2S
= 4 V
g
fs
C
g1ss
Symbol
min.
20
-
Values
typ.
24
2.1
max.
-
2.5
Unit
-
pF
Gate1 input capacitance
V
DS
= 8 V,
I
D
= 10 mA,
V
G2S
= 4 V,
f
= 1 MHz
Gate 2 input capacitance
V
DS
= 8 V,
I
D
= 10 mA,
V
G2S
= 4 V,
f
= 1 MHz
C
g2ss
-
1.2
-
pF
Feedback capacitance
V
DS
= 8 V,
I
D
= 10 mA,
V
G2S
= 4 V,
f
= 1 MHz
C
dg1
-
25
-
fF
Output capacitance
V
DS
= 8 V,
I
D
= 10 mA,
V
G2S
= 4 V,
f
= 1 MHz
C
dss
-
1.1
-
pF
Power gain
V
DS
= 8 V,
I
D
= 10 mA,
V
G2S
= 4 V,
f
= 45 MHz
V
DS
= 8 V,
I
D
= 10 mA,
V
G2S
= 4 V,
f
= 800 MHz
G
p
dB
-
-
28
20
-
-
dB
-
-
2.8
1.8
50
-
-
-
Noise figure
V
DS
= 8 V,
I
D
= 10 mA,
V
G2S
= 4 V,
f
= 45 MHz
V
DS
= 8 V,
I
D
= 10 mA,
V
G2S
= 4 V,
f
= 800 MHz
F
Gain control range
V
DS
= 8 V,
V
G2S
= 4 ...-2 V,
f
= 800 MHz
∆
G
p
40
3
Feb-13-2004
BF998...
Total power dissipation
P
tot
=
ƒ(
T
S
)
BF998, BF998R
Total power dissipation
P
tot
=
ƒ(
T
S
)
BF998W
220
mA
220
mA
180
160
180
160
P
tot
140
120
100
80
60
40
20
0
0
15
30
45
60
75
90 105 120
°C
150
P
tot
140
120
100
80
60
40
20
0
0
15
30
45
60
75
90 105 120
°C
150
T
S
T
S
Output characteristics
I
D
=
ƒ(
V
DS
)
V
G2S
= 4 V
V
G1S
= Parameter
26
mA
22
20
18
16
14
12
10
8
6
4
2
0
0
2
4
6
8
10
V
-0.4V
-0.2V
0V
0.2V
0.4V
Gate 1 forward transconductance
g
fs
=
ƒ(
I
D
)
V
DS
= 5V,
V
G2S
= Parameter
26
mS
4V
22
20
18
2V
g
fs
I
D
16
14
12
10
8
6
4
2
0V
1V
14
0
0
4
8
12
16
mA
24
V
DS
I
D
4
Feb-13-2004
BF998...
Gate 1 forward transconductance
g
fs1
=
ƒ
(
V
G1S
)
26
mS
4V
Drain current
I
D
=
ƒ(
V
G1S
)
V
DS
= 5V
V
G2S
= Parameter
30
4V
2V
mA
22
20
18
2V
G
fs
20
16
14
12
10
8
6
4
2
0
-1
-0.75
-0.5
-0.25
0
0.25
0V
1V
I
D
1V
15
10
0V
5
V
0.75
0
-1
-0.75 -0.5 -0.25
0
0.25
0.5
V
1
V
G1S
V
G1S
Power gain
G
ps
=
ƒ
(
V
G2S
)
f
= 45 MHz
30
Noise figure
F
=
ƒ
(
V
G2S
)
f
= 45 MHz
10
dB
dB
8
7
6
5
4
10
3
2
1
0
0
V
G
ps
20
15
5
F
1
2
4
0
0
1
2
V
4
V
G2S
V
G2S
5
Feb-13-2004
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