3SK321
Silicon N-Channel Dual Gate MOS FET
ADE-208-711A (Z)
2nd. Edition
Dec. 1998
Application
UHF RF amplifier
Features
Low noise figure.
NF = 2.0 dB typ. at f = 900 MHz
Capable of low voltage operation
Provide mini mold packages; MPAK-4R(SOT-143 var.)
Outline
MPAK-4R
2
1
4
3
1. Source
2. Drain
3. Gate2
4. Gate1
3SK321
2
Absolute Maximum Ratings (Ta = 25
C)
Item
Symbol
Ratings
Unit
Drain to source voltage
V
DS
12
V
Gate 1 to source voltage
V
G1S
8
V
Gate 2 to source voltage
V
G2S
8
V
Drain current
I
D
25
mA
Channel power dissipation
Pch
150
mW
Channel temperature
Tch
150
C
Storage temperature
Tstg
55 to +150
C
Attention: This device is very sensitive to electro static discharge.
It is recommended to adopt appropriate cautions when handling this transistor.
Electrical Characteristics (Ta = 25
C)
Item
Symbol
Min
Typ
Max
Unit
Test conditions
Drain to source breakdown
voltage
V
(BR)DSX
12
--
--
V
I
D
= 200
A , V
G1S
= 3 V,
V
G2S
= 3 V
Gate 1 to source breakdown
voltage
V
(BR)G1SS
8
--
--
V
I
G1
=
10
A, V
G2S
= V
DS
= 0
Gate 2 to source breakdown
voltage
V
(BR) G2SS
8
--
--
V
I
G2
=
10
A, V
G1S
= V
DS
= 0
Gate 1 cutoff current
I
G1SS
--
--
100
nA
V
G1S
=
6 V, V
G2S
= V
DS
= 0
Gate 2 cutoff current
I
G2SS
--
--
100
nA
V
G2S
=
6 V, V
G1S
= V
DS
= 0
Drain current
I
DS(on)
0.5
--
10
mA
V
DS
= 6 V, V
G1S
= 0.5V,
V
G2S
= 3 V
Gate 1 to source cutoff voltage V
G1S(off)
0.5
--
+0.5
V
V
DS
= 10 V, V
G2S
= 3V,
I
D
= 100
A
Gate 2 to source cutoff voltage V
G2S(off)
0
--
+1.0
V
V
DS
= 10 V, V
G1S
= 3V,
I
D
= 100
A
Forward transfer admittance
|y
fs
|
16
20.8
--
mS
V
DS
= 6 V, V
G2S
= 3V,
I
D
= 10 mA, f = 1 kHz
Input capacitance
Ciss
1.2
1.5
2.2
pF
V
DS
= 6 V, V
G2S
= 3V,
I
D
= 10 mA, f = 1 MHz
Output capacitance
Coss
0.6
0.9
1.2
pF
Reverse transfer capacitance
Crss
--
0.01
0.03
pF
Power gain
PG
16
19.5
--
dB
V
DS
= 4 V, V
G2S
= 3V,
I
D
= 10 mA, f = 900 MHz
Noise figure
NF
--
2.0
3
dB
Note:
Marking is "ZX"
3SK321
3
Main Characteristics
900MHz Power Gain, Noise Test Circuit
C1, C2
C3
C4C6
R1
R2
R3
Variable Capacitor10pF MAX)
Disk Capacitor1000pF)
Air Capacitor1000pF)
47 k
47 k
4.7 k
26
3
3
L2
18
10
10
L4
29
7
7
L3
1mm Copper wire
Unitmm
RFC1mm Copper wire with enamel 4turns inside dia 6mm
21
10
8
L1
10
Input
Output
C2
C1
L1
L2
L3
L4
S
G1
G2
R1
R2
C3
R3
RFC
C6
C5
C4
D
VG2
VG1
VD
3SK321
4
200
150
100
50
0
50
100
150
200
Channel Power Dissipation Pch (mW)
Ambient Temperature Ta (
C)
Maximum Channel Power
Dissipation Curve
20
16
12
8
4
0
2
4
6
8
10
1.0 V
0.8 V
1.2 V
0.6 V
V = 3 V
G2S
G1S
V = 0.4 V
Drain to source voltage V (V)
DS
Drain current I (mA)
D
Typical Output Characteristics
Pulse test
20
16
12
8
4
0
1
2
3
4
5
G2S
V = 0.5 V
3.0 V
2.5 V
2.0 V
1.5 V
V = 6 V
DS
Gate1 to source voltage V (V)
G1S
Drain current I (mA)
D
Drain Current vs. Gate1 to Source Voltage
1.0 V
Pulse test
20
16
12
8
4
0
1
2
3
4
5
G1S
V = 0.5 V
1.0 V
2.0 V
1.5 V
V = 6 V
DS
Gate2 to source voltage V (V)
G2S
Drain current I (mA)
D
Drain Current vs. Gate2 to Source Voltage
Pulse test
3SK321
5
30
24
18
12
6
2.0
0
V = 3.0 V
G2S
2.5 V
1.0 V
DS
V = 6 V
f = 1 kHz
0.4
0.8
1.2
1.6
0.5 V
Gate1 to source voltage V (V)
G1S
Forward Transfer Admittance vs.
Gate1 to Source Voltage
2.0 V
1.5 V
Forward transfer admittance
|yfs| (mS)
20
0
25
20
15
10
5
1
2
5
10
DS
G2S
V = 4 V
V = 3 V
f = 900 MHz
Power gain PG (dB)
Drain current I (mA)
D
Power Gain vs. Drain Current
20
0
5
4
3
2
1
1
2
5
10
Noise figure NF (dB)
Drain current I (mA)
D
Noise Figure vs. Drain Current
DS
V = 4 V
V = 3 V
f = 900 MHz
G2S
0
25
20
15
10
5
2
4
6
8
10
D
G2S
V = 3 V
I = 10 mA
f = 900 MHz
Power gain PG (dB)
Drain to source voltage V (V)
DS
Power Gain vs. Drain to Source Voltage
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