IFET 2N3958, 2N3957 Datasheet

B-6 01/99

2N3957, 2N3958

N-Channel Dual Silicon Junction Field-Effect Transistor

¥ Low and Medium Frequency

Differential Amplifiers

¥ High Input Impedance

Amplifiers

Absolute maximum ratings at TA= 25¡C

Reverse Gate Source & Reverse Gate Drain Voltage – 50 V
Gate Current 50 mA
Total Device Power Dissipation (each side) 250 mW
@ 85°C Case Temperature (both sides) 500 mW
Power Derating (both sides) 4.3 mW/°C

At 25°C free air temperature: 2N3957 2N3958 Process NJ16
Static Electrical Characteristics Min Max Min Max Unit Test Conditions

Gate Source Breakdown Voltage V

(BR)GSS

– 50 – 50 V IG= – 1 µA, VDS= ØV

– 100 – 100 pA VGS= – 30V, VDS= ØV

Gate Reverse Current I

GSS

– 500 – 500 nA VGS= – 30V, VDS= ØV TA= 125°C

– 50 – 50 pA VDS= 20V, ID= 200 µA

Gate Operating Current I

G

– 250 – 250 nA VDS= 20V, ID= 200 µA TA= 125°C

– 4.2 – 4.2 V VDS= 20V, ID= 50 µA

Gate Source Voltage V
Gate Source Cutoff Voltage V

Gate Source Forward Voltage V
Drain Saturation Current (Pulsed) I

GS

GS(OFF)
GS(F)

DSS

– 0.5 – 4 – 0.5 – 4 V VDS= 20V, ID= 200 µA

– 1 – 4.5 – 1 – 4.5 V VDS= 20V, ID= 1 nA

22VV

= Ø, IG= 1 mA

DS

0.5 5 0.5 5 mA VDS= 20V, VGS= ØV

Dynamic Electrical Characteristics

Common Source
Forward Transconductance

Common Source Output Conductance g
Common Source Input Capacitance C
Drain Gate Capacitance C
Common Source

Reverse Transfer Capacitance

g

fs

os
iss
dgo

C

rss

Noise Figure NF 0.5 0.5 dB
Differential Gate Current | IG1– IG2|10 10nAV

Saturation Drain Current Ratio I
Differential Gate Source Voltage | V

Differential Gate Source
Voltage with Temperature

Transconductance Ratio g

DSS1

∆V

fs1

GS1

GS1

∆T

/ g

1000 3000 1000 3000 µS VDS= 20V, VGS= ØV f = 1 kHz
1000 1000 µS VDS= 20V, VGS= ØV f = 200 MHz

35 35 µS VDS= 20V, VGS= ØV f = 1 kHz

44pFV

= 20V, VGS= ØV f = 1 MHz

DS

1.5 1.5 pF VDS= 10V, IS= ØA f = 1 MHz

1.2 1.2 pF VDS= 20V, VGS= ØV f = 1 MHz
VDS= 20V, VGS= ØV

RG= 10MΩ

= 20V, ID= 200 µA TA= 125°C

DS

/ I

– V

– V

0.9 1 0.85 1 VDS= 20V, VGS= ØV

DSS2

| 20 25 mV V

GS2

68mVV

GS2

= 20V, ID= 200 µA

DS

= 20V, ID= 200 µA

DS

7.5 10 mV VDS= 20V, ID= 200 µA

0.9 1 0.85 1 VDS= 20V, ID= 200 µA f = 1 kHz

fs2

TOÐ71 Package

See Section G for Outline Dimensions

1000 N. Shiloh Road, Garland, TX 75042

[phone] FAX [phone]

f = 100 Hz

TA= 25°C
to – 55°C

TA= 25°C
to 125°C

Pin Configuration

1 Source, 2 Drain, 3 Gate, 5 Source,
6 Drain, 7 Gate

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