Databook.fxp 1/14/99 11:30 AM Page B-6 B-6 01/99 2N3957, 2N3958 N-Channel Dual Silicon Junction Field-Effect Transistor
Absolute maximum ratings at TA = 25¡C ¥ Low and Medium Frequency
Differential Amplifiers
¥ High Input Impedance
Amplifiers At 25°C free air temperature: Reverse Gate Source & Reverse Gate Drain Voltage
Gate Current
Total Device Power Dissipation (each side)
@ 85°C Case Temperature (both sides)
Power Derating (both sides) 2N3957 Static Electrical Characteristics Min Gate Source Breakdown Voltage V(BR)GSS Gate Reverse Current IGSS Gate Operating Current IG Gate Source Voltage VGS Gate Source Cutoff Voltage VGS(OFF) Gate Source Forward Voltage VGS(F) Drain Saturation Current (Pulsed) IDSS Max – 50 2N3958
Min Max – 50 V
50 mA
250 mW
500 mW
4.3 mW/°C Process NJ16
Unit – 50 Test Conditions V IG = – 1 µA, VDS = ØV – 100 – 100 pA VGS = – 30V, VDS = ØV – 500 – 500 nA VGS = – 30V, VDS = ØV – 50 – 50 pA VDS = 20V, ID = 200 µA – 250 – 250 nA VDS = 20V, ID = 200 µA – 4.2 – 4.2 V VDS = 20V, ID = 50 µA TA = 125°C
TA = 125°C – 0.5 –4 – 0.5 –4 V VDS = 20V, ID = 200 µA –1 – 4.5 –1 – 4.5 V VDS = 20V, ID = 1 nA 2 V VDS = Ø, IG = 1 mA 5 mA VDS = 20V, VGS = ØV 1000 3000 1000 3000 µS VDS = 20V, VGS = ØV f = 1 kHz 1000 µS VDS = 20V, VGS = ØV f = 200 MHz 2
0.5 5 0.5 Dynamic Electrical Characteristics
Common Source
Forward Transconductance gfs Common Source Output Conductance gos 35 35 µS VDS = 20V, VGS = ØV f = 1 kHz Common Source Input Capacitance Ciss 4 4 pF VDS = 20V, VGS = ØV f = 1 MHz Drain Gate Capacitance Cdgo 1.5 1.5 pF VDS = 10V, IS = ØA f = 1 MHz Common Source
Reverse Transfer Capacitance Crss 1.2 1.2 pF VDS = 20V, VGS = ØV f = 1 MHz Noise Figure NF 0.5 0.5 dB VDS = 20V, VGS = ØV
RG = 10 MΩ f = 100 Hz Differential Gate Current | IG1 – IG2 | 10 10 nA VDS = 20V, ID = 200 µA TA = 125°C Saturation Drain Current Ratio IDSS1 / IDSS2 Differential Gate Source Voltage | VGS1 – VGS2 | Differential Gate Source
Voltage with Temperature
Transconductance Ratio 0.9 ∆VGS1– VGS2 …
