Datasheet IFN423, IFN422, IFN421 Datasheet (Interfet)

01/99 B-41

IFN421, IFN422, IFN423

Dual N-Channel Silicon Junction Field-Effect Transistor

Absolute maximum ratings at TA= 25¡C

Device Dissipation (Derate 3.2 mW/°C to 50°C) 400 mW
Total Device Dissipation (Derate 6 mW/°C to 150°C) 750 mW
Storage Temperature Range – 65°C to 200°C

TOÐ78 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 25°C 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 IG= – 1 µA, VDS= ØV

Gate to Gate Breakdown Voltage BV

G1G2

±40 V IG= – 1 µA, ID= ØA, IS= ØA

Gate Reverse Current I

GSS

– 1 pA VGS= – 20V, VDS= ØV
– 1 nA VGS= – 20V, VDS= ØV TA= +125°C

Gate Operating Current I

G

– 0.25 pA VDS= 10V, ID= 30 µA

– 250 pA VDS= 10V, ID= 30 µA TA= +125°C

Gate Source Cutoff Voltage V

GS(OFF)

– 0.4 – 2 V VDS= 10V, ID= 1 nA

Gate Source Voltage V

GS

– 1.8 V VDS= 10V, ID= 30 µA

Drain Saturation Current (Pulsed) I

DSS

60 1000 µA VDS= 10V, VGS= ØV

Dynamic Electrical Characteristics

Common Source Forward Transconductance g

fs

100 1500 µS VDS= 10V, VGS= ØV f = 1 kHz

Common Source Output Conductance g

os

3µSVDS= 10V, ID= 30 µA f = 1 kHz

Common Source Input Capacitance C

iss

3pFVDS= 10V, VGS= ØV f = 1 MHz

Common Source Reverse Transfer Capacitance C

rss

1.5 pF VDS= 10V, VGS= ØV f = 1 MHz

Equivalent Circuit Input Noise Voltage ¯e

N

20 70 nV/√Hz VDS= 10V, ID= 30 µA f = 10 Hz

Noise Figure NF 1 dB

VDS= 10V, ID= 30 µA

f = 10 Hz

RG= 10 MΩ

Max - IFN421 IFN422 IFN423

Differential Gate Source Voltage |V

GS1

– V

GS2

| 10 15 25 mV V

DG

= 10V, ID= 30 µA

Differential Gate Source Voltage |V

GS1

– V

GS2

|

TA= – 55°C

10 25 40 µV/°C VDG= 10V, ID= 30 µA TB= 25°C

With Temperature

∆T

TC= 125°C

Min - IFN421 IFN422 IFN423

Common Mode Rejection Ratio CMRR 90 80 80 dB VDG= 10V to 20V, ID= 30 µA

¥ Very High Input Impedance

Differential Amplifiers

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Databook.fxp 1/14/99 12:22 PM Page B-41