Doc 201151 04/12/2022 Rev# A40 ECN# LSK489

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LSK489A/B

Low Noise, Low Capacitance, Monolithic Dual N-Channel JFET Amplifier

Matching Characteristics @ 25°C (unless otherwise stated)

Symbol

Characteristic

Min.

Typ.

Max

Units

Conditions

GS2

GS1

V

V

−

Differential Gate to Source Cutoff

Voltage

-

8

20

m

V

VDS = 10V, ID = 1mA

DSS2

DSS1

I

I

Gate to Source Saturation Current Ratio

0.9

-

1.0

-

VDS = 10V, VGS = 0V

CMRR

Common Mode Rejection Ratio

-

20 log│∆VGS1-2/∆VDS│

95

102

-

dB

VDS = 10V to 20V, ID = 200µA

en

Noise Voltage

-

1.8

-

nV/

√Hz

VDS = 15V, ID = 2.0mA, f = 1kHz,

NBW = 1Hz

en

Noise Voltage

-

3.5

-

nV/

√Hz

VDS = 15V, ID = 2.0mA, f = 10Hz,

NBW = 1Hz

CISS

Common Source Input Capacitance

-

4

-

pF

VDS = 15V, ID = 500µA, f = 1MHz

CRSS

Common Source Reverse Transfer

Capacitance

-

2

-

pF

Electrical Characteristics @ 25°C (unless otherwise stated)

Symbol

Characteristic

Min.

Typ.

Max

Units

Conditions

BVGSS

Gate to Source Breakdown Voltage

-60

-

-

V

VDS = 0, ID = -1nA

V(BR)G1 - G2

Gate to Gate Breakdown Voltage

±30

±45

-

V

IG= ±1µA, ID=IS=0 A (Open Circuit)

VGS(OFF)

Gate to Source Pinch-off Voltage

-1.5

-

-3.5

V

VDS = 15V, ID = 1nA

VGS

Gate to Source Operating Voltage

-0.5

-

-3.5

V

VDS = 15V, ID = 500µA

IDSS

Drain to Source

Saturation Current

LSK489A

2.5

5.5

8.5

mA

VDG = 15V, VGS = 0

LSK489B

8.0

11.5

15.0

IG

Gate Operating Current

-

-2

-25

pA

VDG = 15V, ID = 200µA

-

-0.8

-10

nA

TA = 125°C

IGSS

Gate to Source Leakage Current

-

-

-100

pA

VDG = -15V, VDS = 0

Gfs

Full Conductance Transconductance

1500

-

-

µS

VDG = 15V, VGS = 0, f = 1kHz

Gfs

Transconductance

1000

1500

-

µS

VDG = 15V, ID = 500µA

GOS

Full Output Conductance

-

-

40

µS

VDG = 15V, VGS = 0

GOS

Output Conductance

-

1.8

2.7

µS

VDG = 15V, ID = 200µA