BF994S
Vishay Telefunken
N–Channel Dual Gate MOS-Fieldeffect Tetrode,
Depletion Mode
Electrostatic sensitive device.
Observe precautions for handling.
Applications
Input- and mixer stages especially VHF TV-tuners.
Features
D
Integrated gate protection diodes
D
High cross modulation performance
D
Low noise figure
2
1
D
High AGC-range
D
Low feedback capacitance
D
Low input capacitance
G
2
G
1
D
94 9279
13 579
3
4
12623
BF994 Marking: MG
Plastic case (SOT 143)
1=Source, 2=Drain, 3=Gate 2, 4=Gate 1
S
Absolute Maximum Ratings
T
amb
= 25
_
C, unless otherwise specified
Parameter
Drain - source voltage
Drain current
Gate 1/Gate 2 - source peak current
Total power dissipation
Channel temperature
Storage temperature range
Test Conditions
Type
Symbol
Value
V
DS
20
I
D
30
±I
G1/G2SM
10
P
tot
200
T
Ch
150
T
stg
–55 to +150
Unit
V
mA
mA
mW
°
C
°
C
T
amb
≤
60
°
C
Maximum Thermal Resistance
T
amb
= 25
_
C, unless otherwise specified
Parameter
Test Conditions
Channel ambient on glass fibre printed board (25 x 20 x 1.5) mm
3
plated with 35
m
m Cu
Symbol
R
thChA
Value
450
Unit
K/W
Document Number 85008
Rev. 3, 20-Jan-99
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1 (7)
BF994S
Vishay Telefunken
Electrical DC Characteristics
T
amb
= 25
_
C, unless otherwise specified
Parameter
Drain - source
breakdown voltage
Gate 1 - source
breakdown voltage
Gate 2 - source
breakdown voltage
Gate 1 - source
leakage current
Gate 2 - source
leakage current
Drain current
Test Conditions
I
D
= 10
m
A, –V
G1S
= –V
G2S
= 4 V
±I
G1S
= 10 mA, V
G2S
= V
DS
= 0
±I
G2S
= 10 mA, V
G1S
= V
DS
= 0
±V
G1S
= 5 V, V
G2S
= V
DS
= 0
±V
G2S
= 5 V, V
G1S
= V
DS
= 0
V
DS
= 15 V, V
G1S
= 0, V
G2S
= 4 V
BF994S
BF994SA
BF994SB
Type
Symbol
V
(BR)DS
±V
(BR)G1SS
±V
(BR)G2SS
±I
G1SS
±I
G2SS
I
DSS
I
DSS
I
DSS
–V
G1S(OFF)
–V
G2S(OFF)
4
4
9.5
Min
20
6
Typ
Max
Unit
V
V
V
nA
nA
mA
mA
mA
V
V
20
20
50
50
18
10.5
18
2.5
2.0
Gate 1 - source
cut-off voltage
Gate 2 - source
cut-off voltage
V
DS
= 15 V, V
G2S
= 4 V, I
D
= 20
m
A
V
DS
= 15 V, V
G1S
= 0, I
D
= 20
m
A
Electrical AC Characteristics
V
DS
= 15 V, I
D
= 10 mA, V
G2S
= 4 V, f = 1 MHz , T
amb
= 25
_
C, unless otherwise specified
Parameter
Forward transadmittance
Gate 1 input capacitance
Gate 2 input capacitance
Feedback capacitance
Output capacitance
Power gain
AGC range
Noise figure
Test Conditions
Symbol
y
21s
C
issg1
C
issg2
C
rss
C
oss
G
ps
D
G
ps
F
Min
15
Typ
18.5
2.5
1.2
25
1.0
25
50
1.0
Max
3.0
35
1.3
Unit
mS
pF
pF
fF
pF
dB
dB
dB
V
G1S
= 0, V
G2S
= 4 V
G
S
= 2 mS, G
L
= 0.5 mS, f = 200 MHz
V
G2S
= 4 to –2 V, f = 200 MHz
G
S
= 2 mS, G
L
= 0.5 mS, f = 200 MHz
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Document Number 85008
Rev. 3, 20-Jan-99
BF994S
Vishay Telefunken
Typical Characteristics
(T
amb
= 25
_
C unless otherwise specified)
300
P
tot
– Total Power Dissipation ( mW )
250
I
D
– Drain Current ( mA )
200
150
100
50
0
0
96 12159
22
20
18
16
14
12
10
8
6
4
2
0
20
40
60
80
100 120 140 160
12852
5V
V
DS
= 15V
4V
3V
2V
1V
0
V
G1S
= –1V
–1
–0.5
0.0
0.5
1.0
1.5
T
amb
– Ambient Temperature (
°C
)
V
G2S
– Gate 2 Source Voltage ( V )
Figure 1. Total Power Dissipation vs.
Ambient Temperature
32
28
I
D
– Drain Current ( mA )
24
20
16
0
12
8
4
V
G1S
= –1V
0
0
12849
Figure 4. Drain Current vs. Gate 2 Source Voltage
4.0
V
G2S
= 4V
P
tot
=200mW
C
issg1
– Gate 1 Input Capacitance ( pF )
2V
1.5V
1V
0.5V
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
–1
V
DS
=15V
V
G2S
=4V
f=1MHz
–0.5V
2
4
6
8
10
12
14
16
12853
–0.5
0.0
0.5
1.0
1.5
V
DS
– Drain Source Voltage ( V )
I
D
– Drain Current ( mA )
Figure 2. Drain Current vs. Drain Source Voltage
22
20
18
I
D
– Drain Current ( mA )
16
14
12
10
8
6
4
2
0
–1
12851
Figure 5. Gate 1 Input Capacitance vs. Drain Current
3.0
C
issg2
– Gate 2 Input Capacitance ( pF )
6V 5V 4V 3V
V
DS
= 15V
2V
1V
2.5
2.0
1.5
1.0
0.5
0
–2
–1
0
1
2
V
DS
=15V
V
G1S
=0
f=1MHz
0.5V
0
V
G2S
= –1V
–0.5
0.0
0.5
1.0
1.5
3
4
5
V
G1S
– Gate 1 Source Voltage ( V )
12854
V
G2S
– Gate 2 Source Voltage ( V )
Figure 3. Drain Current vs. Gate 1 Source Voltage
Figure 6. Gate 2 Input Capacitance vs.
Gate 2 Source Voltage
Document Number 85008
Rev. 3, 20-Jan-99
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3 (7)
BF994S
Vishay Telefunken
2.0
C
oss
– Output Capacitance ( pF )
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
12856
12
V
G2S
=4V
f=1MHz
Im ( y ) ( mS )
11
f=700MHz
10
8
6
4
2
50MHz
0
2
4
6
8
10 12 14 16 18 20
12860
600MHz
500MHz
400MHz
300MHz
200MHz
V
DS
=15V
V
G2S
=4V
I
D
=10mA
f=50...700MHz
1.5
2.0
2.5
3.0
0
0.5
1.0
V
DS
– Drain Source Voltage ( V )
Re (y
11
) ( mS )
Figure 7. Output Capacitance vs. Drain Source Voltage
10
– Transducer Gain ( dB )
0
–10
–20
–30
–40
–50
–60
–2.0 –1.5 –1.0 –0.5 0.0
12855
Figure 10. Short Circuit Input Admittance
0
–4
Im ( y ) ( mS )
21
–8
–12
–16
–20
f=50MHz
150MHz
300MHz
500MHz
700MHz
I
D
=5mA
10mA
20mA
V
DS
=15V
V
G2S
=4V
f=50...700MHz
f= 200MHz
4V
3V
2V
1V
0
–0.2V
–0.4V
–0.6V
–0.8V
V
G2S
=–1V
S
21
2
0.5
1.0
1.5
2.0
12861
0
2
4
6
8 10 12 14 16 18 20 22
Re (y
21
) ( mS )
V
G1S
– Gate 1 Source Voltage ( V )
Figure 8. Transducer Gain vs. Gate 1 Source Voltage
y
21s
– Forward Transadmittance ( mS )
20
18
16
14
12
10
8
6
4
2
0
0
12850
Figure 11. Short Circuit Forward Transfer Admittance
4.0
3.5
3.0
Im ( y ) ( mS )
22
2.5
2.0
1.5
1.0
f=700MHz
600MHz
500MHz
400MHz
300MHz
200MHz
V
DS
=15V
V
G2S
=4V
I
D
=10mA
f=50...700MHz
1.2
1.6
2.0
V
DS
=15V
f=1MHz
4V
3V
2V
1V
V
G2S
=0
2
4
6
8
10
12
14
0.5V
16
18
12862
0.5
0
0
50MHz
0.4
0.8
I
D
– Drain Current ( mA )
Re (y
22
) ( mS )
Figure 9. Forward Transadmittance vs. Drain Current
Figure 12. Short Circuit Output Admittance
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Document Number 85008
Rev. 3, 20-Jan-99
BF994S
Vishay Telefunken
V
DS
= 15 V, I
D
= 10 mA, V
G2S
= 4 V , Z
0
= 50
S
11
j
120°
j0.5
j2
150°
j0.2
j5
200
700MHz
30°
W
90°
60°
S
12
0
0.2
0.5
1
2
5
50
1
50
180°
0.08
0.16
0°
–j0.2
12 964
S
21
90°
120°
60°
150°
200
50
–j0.2
–150°
–30°
–120°
12 966
–60°
–90°
12 967
Figure 14. Forward transmission coefficient
Document Number 85008
Rev. 3, 20-Jan-99
ÁÁÁÁÁÁÁÁÁÁ
Á Á
180°
ÁÁÁÁÁÁÁÁÁÁ
Á Á
ÁÁÁÁÁÁÁÁÁÁ
Á Á
450
700MHz
–j0.5
–j
–j2
450
700MHz
1
2
200
–j5
–150°
–30°
–120°
12 965
–60°
–90°
Figure 13. Input reflection coefficient
Figure 15. Reverse transmission coefficient
S
22
j
j0.5
30°
j0.2
j5
j2
0°
0
0.2
0.5
1
2
5
50
1
700MHz
–j5
–j0.5
–j
–j2
Figure 16. Output reflection coefficient
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