01/99
B-41
IFN421, IFN422, IFN423
Dual N-Channel Silicon Junction Field-Effect Transistor
Absolute maximum ratings at T
A
= 25C
Device Dissipation (Derate 3.2 mW/C to 50C)
400 mW
Total Device Dissipation (Derate 6 mW/C to 150C)
750 mW
Storage Temperature Range
65C to 200C
TO78 Package
See Section G for Outline Dimensions
Pin Configuration
1 Source 1, 2 Drain 1, 3 Gate 1, 4 Case,
5 Source 2, 6 Drain 2, 7 Gate 2,
8 Omitted
At 25C free air temperature:
IFN421, IFN422, IFN423
Process NJ01
Static Electrical Characteristics
Min
Typ
Max
Unit
Test Conditions
Gate Source Breakdown Voltage
V
(BR)GSS
40
60
V
I
G
= 1 A, V
DS
= V
Gate to Gate Breakdown Voltage
BV
G1G2
40
V
I
G
= 1 A, I
D
= A, I
S
= A
Gate Reverse Current
I
GSS
1
pA
V
GS
= 20V, V
DS
= V
1
nA
V
GS
= 20V, V
DS
= V
T
A
= +125C
Gate Operating Current
I
G
0.25
pA
V
DS
= 10V, I
D
= 30 A
250
pA
V
DS
= 10V, I
D
= 30 A
T
A
= +125C
Gate Source Cutoff Voltage
V
GS(OFF)
0.4
2
V
V
DS
= 10V, I
D
= 1 nA
Gate Source Voltage
V
GS
1.8
V
V
DS
= 10V, I
D
= 30 A
Drain Saturation Current (Pulsed)
I
DSS
60
1000
A
V
DS
= 10V, V
GS
= V
Dynamic Electrical Characteristics
Common Source Forward Transconductance
g
fs
100
1500
S
V
DS
= 10V, V
GS
= V
f = 1 kHz
Common Source Output Conductance
g
os
3
S
V
DS
= 10V, I
D
= 30 A
f = 1 kHz
Common Source Input Capacitance
C
iss
3
pF
V
DS
= 10V, V
GS
= V
f = 1 MHz
Common Source Reverse Transfer Capacitance
C
rss
1.5
pF
V
DS
= 10V, V
GS
= V
f = 1 MHz
Equivalent Circuit Input Noise Voltage
e
N
20
70
nV/
Hz
V
DS
= 10V, I
D
= 30 A
f = 10 Hz
Noise Figure
NF
1
dB
V
DS
= 10V, I
D
= 30 A
f = 10 Hz
R
G
= 10 M
Max - IFN421 IFN422 IFN423
Differential Gate Source Voltage
|V
GS1
V
GS2
|
10
15
25
mV
V
DG
= 10V, I
D
= 30 A
Differential Gate Source Voltage
|V
GS1
V
GS2
|
T
A
= 55C
10
25
40
V/C
V
DG
= 10V, I
D
= 30 A
T
B
= 25C
With Temperature
T
T
C
= 125C
Min - IFN421 IFN422 IFN423
Common Mode Rejection Ratio
CMRR
90
80
80
dB
V
DG
= 10V to 20V, I
D
= 30 A
Very High Input Impedance
Differential Amplifiers
Electrometers
1000 N. Shiloh Road, Garland, TX 75042
(972) 487-1287
FAX
(972) 276-3375
www.interfet.com
Databook.fxp 1/14/99 12:22 PM Page B-41
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