2SK291
Silicon N-Channel Junction FET
Application
Low frequency low noise amplifier
Outline
TO-92 (2)
1. Drain
2. Source
3. Gate
3
2
1
2SK291
Absolute Maximum Ratings
(Ta = 25°C)
Item
Gate to drain voltage
Gate to source voltage
Drain current
Gate current
Channel power dissipation
Channel temperature
Storage temperature
Symbol
V
GDO
V
GSO
I
D
I
G
Pch
Tch
Tstg
Ratings
–15
–15
50
5
300
150
–55 to +150
Unit
V
V
mA
mA
mW
°C
°C
Electrical Characteristics
(Ta = 25°C)
Item
Gate to drain breakdown
voltage
Gate to source breakdown
voltage
Gate cutoff current
Drain current
Gate to source cutoff voltage
Forward transfer admittance
Input capacitance
Symbol
V
(BR)GDO
V
(BR)GSO
I
GSS
I
DSS
*
1
V
GS(off)
|y
fs
|
Ciss
Min
–15
–15
—
5
—
25
—
—
Typ
—
—
—
—
—
45
8.5
1.2
Max
—
—
10
50
–3.0
—
—
—
Unit
V
V
nA
mA
V
mS
pF
Test conditions
I
G
= –100
µA
I
G
= –100
µA
V
GS
= –7 V, V
DS
= 0
V
DS
= 5 V, V
GS
= 0
V
DS
= 5 V, I
D
= 100
µA
V
DS
= 5 V, V
GS
= 0, f = 1 kHz
V
DS
= 5 V, V
GS
= 0, f = 1 MHz
Noise voltage referred to input e
n
Note:
Grade
I
DSS
nV/√Hz V
DS
= 5 V, I
D
= 5 mA, Rg = 0,
f = 100 kHz
T
36 to 50
1. The 2SK291 is grouped by I
DSS
as follows.
P
5 to 16
Q
14 to 24
R
20 to 32
S
28 to 42
2
2SK291
Maximum Channel Power
Dissipation Curve
Channel Power Dissipation P
ch
(mW)
450
Typical Output Characteristics
30
V
DS
= 5 V
Drain Current I
D
(mA)
V
GS
= 0
20
V
–0.1
–0.2
–0.3
300
150
10
–0.4
–0.5
–0.6
–0.8
0
50
100
150
Ambient Temperature Ta (°C)
0
2
4
Drain to Source Voltage V
DS
(V)
6
Typical Transfer Characteristics
Forward Transfer Admittance
y
fs
(mS)
30
V
DS
= 5 V
Drain Current I
D
(mA)
60
50
40
30
20
10
0
–2.0
Forward Transfer Admittance vs.
Drain to Source Voltage
V
DS
= 5 V
f = 1 kHz
20
10
0
–2.0
–1.6
–0.8
–0.4
–1.2
Gate to Source Voltage V
GS
(V)
0
–1.6
–1.2
–0.8
–0.4
Gate to Source Voltage V
GS
(V)
0
3
2SK291
Input Capacitance vs.
Gate to Source Voltage
Noise Voltage Referred to Input vs.
Signal Source Resistance
Hz)
Noise Voltage Referred to Input e
n
(nV/
√
14
Input Capacitance C
iss
(pF)
V
DS
= 5 V
f = 1 MHz
20
10
5
V
DS
= 5 V
I
D
= 5 mA
Ta = 25°C
f = 120 Hz
100 kHz
12
10
2
1.0
0.5
8
6
√
4 KTR
g
1
10
1k
10 k
100
Signal Source Resistance R
g
(Ω)
4
–1.0
0.2
–0.8
–0.6
–0.4
–0.2
Gate to Source Voltage V
GS
(V)
0
Noise Voltage Referred
to Input vs. Frequency
Noise Voltage Referred to Input vs.
Drain to Source Voltage
Hz)
Noise Voltage Referred to Input e
n
(nV/
√
50
V
DS
= 5 V
R
g
= 0
Hz)
Noise Voltage Referred to Input e
n
(nV/
√
20
10
5
f = 1 kHz
I
D
= 10 mA
R
g
= 0
20
10
5
2
1.0
0.5
2
1.0
0.5
10
I
D
=
2m
A
5m
A
10
mA
100 kHz
100
10 k
1k
Frequency f (Hz)
100 k
0.2
0.2
0.5 1.0
2
5
10 20
Drain to Source Voltage V
DS
(V)
4
2SK291
Equivalent Noise Resistance vs.
Drain Current
Equivalent Noise Resistance R
eq
(Ω)
1,000
500
V
DS
= 5 V
f = 0.5~4 MHz
Equivalent Noise Resistance R
eq
(Ω)
70
V
DS
= 5 V
I
D
= 10 mA
Equivalent Noise Resistance
vs. Frequency
60
200
100
50
50
40
20
10
1
2
5
10
20
50
Drain Current I
D
(mA)
100
30
20
0
1
2
3
4
Frequency f (MHz)
5
5