LSK389 A/B/C/D
Ultra-Low Noise Monolithic Dual N-Channel JFET Amplifier
INDUSTRY’S FIRST 100% TESTED LOWEST NOISE JFET
Absolute Maximum Ratings
@ 25 °C (unless otherwise stated)
S2
Maximum Temperatures
Storage Temperature
Junction Operating Temperature
D2
-65 to +150°C
G2
-55 to +150°C
4
3
6
1
5
G1
D1
2
S1
Maximum Power Dissipation
Continuous Power Dissipation @ +25°C
TO-71 6L
Top View
400mW
Maximum Currents
Gate Forward Current
SOIC 8L
Top View
IG(F) = 10mA
Maximum Voltages
Gate to Source
VGSS = 40V
Gate to Drain
VGDS = 40V
Features
• Ultra-Low Noise: en = 1.3nV/√Hz
(typ), f = 1.0kHz and NBW = 1.0Hz
• Ultra-Low Noise: 1.5nV/√Hz (typ),
f = 10Hz and NBW = 1.0Hz
• Tight Matching:
IVGS1-2I = 15mV max
• High Breakdown Voltage:
BVGSS = 40V max
• High Gain: Gfs = 20mS (typ)
• Low Capacitance: 25pF (typ)
• Improved Second Source
Replacement for 2SK389
Applications
Benefits
• Improved System Noise Performance
• Unique Monolithic Dual Design
Construction of Interleaving Both
JFETs on the Same Piece of Silicon
• Excellent Matching and Thermal
Tracking
• Great for Maximizing Battery
Operated Applications by Providing a
Wide Output Swing
• A High Signal to Noise Ratio as a
Result of the LSK389's Low and
Tightly Matched Gate Threshold
Voltages
• Audio Amplifiers and Preamps
• Discrete Low-Noise Operational
Amplifiers
• Battery-Operated Audio Preamps
• Audio Mixer Consoles
• Acoustic Sensors
• Sonic Imaging
• Instrumentation Amplifiers
• Microphones
• Sonobouys
• Hydrophones
• Chemical and Radiation Detectors
Description
The LSK389 is the industry’s lowest noise Dual N Channel JFET, 100% tested, guaranteed to meet 1/f and
broadband noise specifications, while eliminating burst (RTN
or popcorn) noise entirely. The LSK389 Series, Monolithic
Dual N-Channel JFETs were specifically designed to
provide users a better performing, less time consuming
and cheaper solution for obtaining tighter IDSS
matching, and better thermal tracking, than matching
individual JFETs. The LSK389 features four grades of
IDSS: 2.6-6.5mA, 6.0-12.0mA, 10.0-20.0mA and 1730mA, with an IDSS match of 10 percen t, a gate
threshold offset of 15mV, a voltage noise (en) of
1.3nV/√Hz typical at f = 1.0kHZ, with a Gain of 20mS
typical, and 25pF of capacitance typical. The LSK389
provides a wide output swing, and a high signal
Doc 201122 04/07/2021 Rev# A25 ECN# LSK389
to noise ratio as a result of the LSK389's tightly matched
and low gate threshold voltages. The 40V breakdown
provides maximum linear headroom in high transient
program content amplifiers.
Additionally, the LSK389 provides a low input noise to
capacitance product that has nearly zero popcorn noise.
The narrow ranges of the IDSS electrical grades
combined with the superior matching performance of the
LSK389's monolithic dual construction promote ease of
device tolerance in low voltage application s, as compared
to matching single JFETs. Available in surface mount
SOIC 8L and thru-hole TO-71 6L packages.
Contact the factory for tighter noise and other
specification selections. For equivalent single N-Channel
version, please refer to the LSK170 datasheet.
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Page 1 of 8
LSK389 A/B/C/D
Ultra-Low Noise Monolithic Dual N-Channel JFET Amplifier
Electrical Characteristics @ 25°C (unless otherwise stated)
SYMBOL
CHARACTERISTIC
MIN
TYP
MAX
UNITS
BVGSS
Gate to Source Breakdown Voltage
-40
---
---
V
VDS = 0, ID = -100µA
VGS(OFF)
Gate to Source Pinch-off Voltage
V
VDS = 10V, ID = 0.1µA
IDSS
Drain to Source Saturation
Current
-0.3
---
-1.6
LSK389A
2.6
---
6.5
LSK389B
6
---
12
LSK389C
10
---
20
LSK389D
17
---
30
CONDITIONS
mA
VDS = 10V, VGS = 0
IGSS
Gate to Source Leakage Current
---
-100
-300
pA
VGS = -25V, VDS = 0
IG1G2
Gate to Gate Isolation Current
---
±1.0
±50
nA
VG1-G2 = ±45V, ID = IS = 0A
Gfs
Full Conduction Transconductance
8
20
---
mS
VDS = 10V, VGS = 0, f = 1kHz
en
Noise Voltage
---
1.3
1.9
nV/√Hz
VDS = 10V, ID = 2mA, f = 1kHz,
NBW = 1Hz
en
Noise Voltage
---
1.5
4.0
nV/√Hz
VDS = 10V, ID = 2mA, f = 10Hz,
NBW = 1Hz
CISS
Common Source Input Capacitance
---
25
---
pF
VDS = 10V, VGS = 0, f = 1MHz,
CRSS
Common Source Reverse Transfer Cap.
---
5.5
---
pF
VDG = 10V, ID = 0, f = 1MHz,
Matching Characteristics @ 25°C (unless otherwise stated)
SYMBOL
CHARACTERISTIC
MIN
TYP
MAX
UNITS
VGS1 − VGS2
Differential Gate to Source Cutoff Voltage
---
6.0
15
mV
CONDITIONS
VDS = 10V, ID = 1mA
IDSS1
IDSS2
Saturation Drain Current Ratio
0.9
1.0
1.1
n/a
VDS = 10V, VGS = 0V
Notes
1. Absolute maximum ratings are limiting values above which serviceability may be impaired.
2. Pulse Test: PW ≤ 300µs, Duty Cycle ≤ 3%
3. All characteristics MIN/TYP/MAX numbers are absolute values. Negative values indicate electrical polarity only.
Information furnished by Linear Integrated Systems is believed to be accurate and reliable. However, no responsibility is assumed
for its use; nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by
implication or otherwise under any patent or patent rights of Linear Integrated Systems.
Doc 201122 04/07/2021 Rev# A25 ECN# LSK389
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Page 2 of 8
LSK389 A/B/C/D
Ultra-Low Noise Monolithic Dual N-Channel JFET Amplifier
Typical Characteristics
LSK389B
LSK389A
0.12mA
10,000
1.5mA
10,000
0.4mA
1,000
3.6mA
1,000
0.84mA
9.0mA
100
IG (pA)
IG (pA)
1.44mA
2.2mA
3.04mA
10
100
10.3mA
0.20mA
10
0.04mA
1.0
1.0
0.1
4.0
8.0
16.0
12.0
20.0
24.00
0.1
4.0
8.0
20.0
VDS(v)
Figure 1. Gate Current (IG) vs. VDS vs. ID
Figure 2. Gate Current (IG) vs. VDS vs. ID
LSK389C
24.00
LSK389D
10,000
1,000
1,000
100
100
IG (pA)
10,000
IG (pA)
16.0
12.0
VDS(v)
10
10
1
1
0
0
4
8
12
16
20
24
8
12
16
20
24
VDS(V)
Figure 4. Gate Current (IG) vs. VDS vs. ID
VDS(V)
Figure 3. Gate Current (IG) vs. VDS vs. ID
Doc 201122 04/07/2021 Rev# A25 ECN# LSK389
4
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Page 3 of 8
LSK389 A/B/C/D
Ultra-Low Noise Monolithic Dual N-Channel JFET Amplifier
Typical Characteristics
LSK389B
LSK389A
3.04mA
100
150
10.3mA
2.2mA
5.5mA
0.84mA
60
7.7mA
120
1.44mA
0.4mA
0.12mA
0.04mA
40
GOS (µS)
GOS (µS)
80
20
90
3.6mA
2mA
60
0.9mA
30
0.0
4.0
8.0
16.0
12.0
20.0
0.0
5.0
24.0
9.0
13.0
17.0
21.0
25.0
VDS(v)
VDS(v)
Figure 6. Output Conductance - GOS vs. VDS vs. ID
Figure 5. Output Conductance - GOS vs. VDS vs. ID
LSK389D
LSK389C
900
600
800
500
700
600
GOS(uS)
GOS(uS)
400
300
500
400
300
200
200
100
100
0
0
4
8
12
16
20
24
VDS(V)
Figure 7. Output Conductance - GOS vs. VDS vs. ID
Doc 201122 04/07/2021 Rev# A25 ECN# LSK389
www.linearsystems.com
4
8
12
16
20
24
VDS(V)
Figure 8. Output Conductance - GOS vs. VDS vs. ID
Page 4 of 8
LSK389 A/B/C/D
Ultra-Low Noise Monolithic Dual N-Channel JFET Amplifier
Typical Characteristics
LSK389B
LSK389A
0V
4.0
0V
10.0
-0.10V
8.0
3.2
2.4
-0.10V
1.6
ID (mA)
ID (mA)
-0.05V
6.0
-0.20V
4.0
-0.30V
-0.15V
0.8
0.0
-0.20V
-0.25V
0.0
15.0
10.0
5.0
20.0
25.00
-0.40V
2.0
-0.50V
0.0
0.0
15.0
10.0
5.0
20.0
25.00
VDS(v)
VDS(v)
Figure 10. ID vs. VDS vs. VGS
Figure 9. ID vs. VDS vs. VGS
LSK389D
LSK389C
LSK389C
25
25
30
0V
0V
25
20
20
-0.2V
1515
ID (mA)
ID (mA)
ID(mA)
-0.2V
1010
-0.4V
(mA)
IID(mA)
D
20
15
-0.4V
10
-0.6V
55
-0.6V
00
0 0
55
10
10
15
15
20
20
-0.8V
-1.2V
2525
VDS(V)
V (v)
Figure
11.11.
ID ID
vs.DS
VDS
vs.vs.
VGS
Figure
vs.
VDS
VGS
Figure 11. ID vs. VDS vs. VGS
Doc 201122 04/07/2021 Rev# A25 ECN# LSK389
-0.8V
5
-1.0V
-1.2V
-1.6V
0
0
5
10
15
20
25
VDS(V)
VDS(v)
Figure 12. ID vs. VDS vs. VGS
Figure 12. ID vs. VDS vs. VGS
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Page 5 of 8
LSK389 A/B/C/D
Ultra-Low Noise Monolithic Dual N-Channel JFET Amplifier
Typical Characteristics
LSK389B
LSK389A
2.5
0V
10.0
0V
8.0
2.0
-0.05V
-0.10V
6.0
ID (mA)
ID (mA)
1.5
1.0
-0.10V
4.0
0.5
-0.15V
2.0
0.0
-0.20V
-0.25V
2.0
0.0
1.2
0.8
0.4
1.6
-0.20V
-0.30V
0.0
-0.40V
-0.50V
0.0
0.8
0.4
1.2
Figure 13. ID vs. VDS vs. VGS
VDS(v)
Figure 14. ID vs. VDS vs. VGS
LSK389C
LSK389D
VDS(v)
16
1.6
22
0V
2.0
0V
20
14
18
12
-0.2V
8
IID(mA)
D(mA)
14
10
(mA)
IDID(mA)
- 0.2V
16
12
- 0.4V
10
6
8
-0.4V
4
2
- 0.6V
-1.2V
0
0.0
0.5
1.0
1.5
VDS(V)
Figure 15. ID vs. VDS vs. VGS
Doc 201122 04/07/2021 Rev# A25 ECN# LSK389
2.0
www.linearsystems.com
- 0.6V
6
4
- 0.8V
2
- 1.0V
- 1.2V
- 1.6V
0
0.0
0.5
1.0
1.5
VDS(V)
Figure 16. ID vs. VDS vs. VGS
2.0
Page 6 of 8
LSK389 A/B/C/D
Ultra-Low Noise Monolithic Dual N-Channel JFET Amplifier
Typical Characteristics
Common Source Forward Transconductance
vs. Drain Current
LSK389A & B
Common Source Forward Transconductance
vs. Drain Current
LSK389C & D
45
25.0
B
30
GFS(mS)
GFS (mS)
GFS (mS)
C
35
A
20.0
D
40
15.0
25
20
15
10.0
10
5.0
0.0
0.0
5
0
2.0
4.0
6.0
8.0
0
10.0
4
8
ID(mA)
Figure 17. GFS vs. ID
12
16
20
ID(mA)
Figure 18. GFS vs. ID
24
28
LSK389C & D
LSK389A & B
30
10.0
25
8.0
20
ID (mA)
ID (mA)
6.0
15
4.0
10
2.0
5
0.0
0.0
-0.4
-0.8
-1.2
VGS(V)
-1.6
-2.0
Figure 19. ID vs. VGS
Doc 201122 04/07/2021 Rev# A25 ECN# LSK389
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0
-0.4
-0.9
-1.4
VGS(V)
Figure 20. ID vs. VGS
-1.9
-2.4
Page 7 of 8
LSK389 A/B/C/D
Ultra-Low Noise Monolithic Dual N-Channel JFET Amplifier
Typical Characteristics
Drain Current Transconductance
vs. Gate-Source Cutoff Voltage
Equivalent Input Noise Voltage
vs. Frequency
45
22
20
40
18
35
16
14
30
12
10
25
8
6
20
2.0
en-Noise Voltage (nv/√Hz)
gfs @ VDS = 10V, VGS = 0V, f = 1kHz
IDSS @ VDS = 10V, VGS = 0V
gfs-Forward Transconductance(mS)
IDSS-Saturation Drain Current(mA)
24
1.6
1.4
1.2
1.0
0.8
4
-1.1
-1.0
-.90
-.80
-.70
-.60
-.50
-.40
10
100
1,000
Figure 22.
f - Frequency (Hz)
10,000
100,000
-1.2
15
2
VDS=10V
ID=2mA
1.8
VGS(v)
Figure 21. VGS (cutoff) vs. IDss vs. GFS
Ordering Information
Package Dimensions
TO-71 6 Lead
Standard Part Call-Out
Bottom View
Side View
LSK389A/B/C or D TO-71 6L RoHS
LSK389A/B/C or D SOIC 8L RoHS
4
6
5
Custom Part Call-Out
(Custom Parts Include SEL + 4 Digit Numeric Code)
DIMENSIONS IN INCHES
SOIC 8 Lead
0.049
0.061
Top View
S1
D1
SS
G1
LSK389A/B/C or D TO-71 6L RoHS SELXXXX
Side View
LSK389A/B/C or D SOIC 8L RoHS SELXXXX
G2
SS
DIMENSIONS IN INCHES
D2
S2
SS: SUBSTRATE, LEAVE THESE PINS FLOATING (N/C)
Doc 201122 04/07/2021 Rev# A25 ECN# LSK389
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