Datasheet u421_u423 Datasheet

PRODUCT SUMMARY

U421/423

Vishay Siliconix

Monolithic N-Channel JFET Duals

Part Number V

U421 -0.4 to-2 -40 0.3 -0.25 10
U423 -0.4 to -2 -40 0.3 -0.25 25

GS(off)

(V) V

(BR)GSS

Min (V) gfs Min (mS) IG Max (pA) V

GS1

- V

 Max (mV)

GS2

FEATURES BENEFITS APPLICATIONS

D Monolithic Design
D High Slew Rate
D Low Offset/Drift Voltage
D Low Gate Leakage: 0.2 pA
D Low Noise
D High CMRR: 102 dB

D Tight Differential Match vs. Current
D Improved Op Amp Speed, Settling Time Accuracy
D Minimum Input Error/Trimming Requirement
D Insignificant Signal Loss/Error Voltage
D High System Sensitivity
D Minimum Error with Large Input Signals

D Ultralow Input Current

Differential Amps

D High-Speed Comparators
D Impedance Converters

DESCRIPTION

The U421/423 are monolithic dual n-channel JFETs designed
to provide very high input impedance for differential
amplification and impedance matching. Among its many
unique features, this series offers operating gate current
specified at -250 fA.

The hermetic TO-78 package is available with full military
processing (see Military Information).

For similar products see the low-noise U/SST401 series and
high-gain 2N5911/5912 data sheets.

TO-78

S

1

D

1

2

G

1

ABSOLUTE MAXIMUM RATINGS

Gate-Drain, Gate-Source Voltage -40 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gate-Gate Voltage "40 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gate Current 10 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lead Temperature (

Storage Temperature -65 to 200_C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating Junction Temperature -55 to 150_C. . . . . . . . . . . . . . . . . . . . . . . . . .

Document Number: 70248
S-03180—Rev. D, 17-Feb-03

1

/16” from case for 10 sec.) 300 _C. . . . . . . . . . . . . . . . . .

1

3

4

Case, Substrate

Top View

G

2

7

D

2

6

5

S

2

Power Dissipation : Per Side

Notes
a. Derate 2.4 mW/_C above 25_C
b. Derate 4 mW/_C above 25_C

Total

b

a

300 mW. . . . . . . . . . . . . . . . . . . . . . . .

500 mW. . . . . . . . . . . . . . . . . . . . . . . . . . .

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7-1

U421/423

VDS = 10 V, VGS = 0 V, f = 1 kH

Vishay Siliconix

SPECIFICATIONS (TA = 25_C UNLESS OTHERWISE NOTED)

Limits

U421 U423

Parameter

Symbol

Specific Test Conditions Typ

a

Min Max Min Max

Unit

Static

Gate-Source
Breakdown Voltage

Gate-Gate
Breakdown Voltage

Gate-Source
Cutoff Voltage

Saturation Drain Current I

Gate Reverse Current I

Gate Operating Current I

Drain-Source
On-Resistance

Gate-Source Voltage V
Gate-Source

Forward Voltage

V

(BR)GSS

V

(BR)G1 - G2

V

GS(off)

DSS

GSS

G

r

DS(on)

GS

V

GS(F)

IG = -1 mA, VDS = 0 V

IG = "1 mA, ID = 0, IS = 0 "55 "40 "40

VDS = 10 V, ID = 1 nA -1.2 -0.4 -2 -0.4 -2

VDS = 10 V, VGS = 0 V 400 60 1000 60 1000

VGS = -20 V, VDS = 0 V -0.6 -1 -1 pA

TA = 125_C

VDG = 10 V, ID = 30 mA

TA = 125_C

VGS = 0 V, ID = 10 mA

VDG = 10 V, ID = 30 mA

IG = 1 mA , VDS = 0 V 0.7

-60 -40 -40

-0.3 -1 -1 nA

-0.2 -0.25 -0.25

-150 -250 -250

2000

-0.8 -1.8 -1.8

V

mA

pA

W

V

Dynamic

Common-Source Forward
Transconductance

Common-Source
Output Conductance

Common-Source Forward
Transconductance

Common-Source
Output Conductance

Common-Source
Input Capacitance

Common-Source
Reverse Transfer
Capacitance

Equivalent Input
Noise Voltage

Noise Figure NF

g

fs

g

os

g

fs

g

os

C

iss

C

rss

e

n

VDS = 10 V, ID = 30 mA , f = 1 kHz

VDS = 10 V, VGS = 0 V, f = 1 MHz

VDS = 10 V, ID = 30 mA , f = 10 Hz

z

RG = 10 MW

0.6 0.3 1.5 0.3 1.5 mS

4 10 10

0.2 0.12 0.35 0.12 0.35 mS

0.4 3 3

1.4 3 3

0.7 1.5 1.5

30 70 70

1 1 dB

mS

mS

pF

nV⁄

√Hz

Matching

Differential
Gate-Source Voltage

Gate-Source Voltage
Differential Change
with Temperature

Common Mode
Rejection Ratio

Notes
a. Typical values are for DESIGN AID ONLY, not guaranteed or subject to production testing. NNT

Ť

V

GS1–VGS2

Ť

D

V

GS1–VGS2

DT

CMRR

Ť

Ť

VDG = 10 V, ID = 30 mA

VDG = 10 V, ID = 30 mA

T

= -55 to 125_C

A

VDG = 10 to 20 V, ID = 30 mA

102 90 80 dB

10 25 mV

10 40

mV/_C

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7-2

Document Number: 70248

S-03180—Rev. D, 17-Feb-03

TYPICAL CHARACTERISTICS (TA = 25_C UNLESS OTHERWISE NOTED)

Drain Current and Transconductance

1.6

2

vs. Gate-Source Cutoff Voltage

1

g

fs

- Forward Transconductance (mS)

0.8

100 nA

10 nA

Gate Leakage Current

U421/423

Vishay Siliconix

ID = 100 mA

g

fs

1.2

0.8

- Saturation Drain Current (mA)

0.4

DSS

I

I

@ VDS = 10 V, VGS = 0 V

DSS

@ VDS = 10 V, VGS = 0 V

g

fs

f = 1 kHz

0

0-5-1 -2 -3 -4

V

- Gate-Source Cutoff Voltage (V) VDG - Drain-Gate Voltage (V)

GS(off)

Output Characteristics Output Characteristics

0.5
V

= -1 VV

= -1 V V

GS(off)

GS(off)

0.4

0.3

0.2

- Drain Current (mA)

D

I

0.1

0

0204 8 12 16

V

- Drain-Source Voltage (V) VDS - Drain-Source Voltage (V)

DS

I

DSS

VGS= 0 V

-0.1 V

-0.2 V

-0.3 V

-0.4 V

-0.5 V

-0.6 V

-0.7 V

0.6

0.4

0.2

0

1 nA

TA = 125_C

100 pA

- Gate Leakage

10 pA

G

I

1 pA

TA = 25_C

0.1 pA
0302010 40 50

1

GS(off)

0.8

0.6

0.4

- Drain Current (mA)

D

I

0.2

0

0204 8 12 16

= -1.5 V

100 mA

I

GSS

-1.0 V

30 mA

@ 25_C

I

GSS

30 mA

VGS= 0 V

-0.2 V

-0.4 V

-0.6 V

-0.8 V

0.25

V

= -1 V

GS(off

)

0.2

0.15

0.1

- Drain Current (mA)

D

I

0.5

0

010.80.60.40.2
VDS - Drain-Source Voltage (V)

Document Number: 70248
S-03180—Rev. D, 17-Feb-03

Output Characteristics

VGS= 0 V

-0.1 V

-0.2 V

-0.3 V

-0.4 V

-0.5 V

-0.6 V

-0.7 V

0.5

V

GS(off)

0.4

0.3

0.2

- Drain Current (mA)

D

I

0.1

0

010.80.60.40.2

Output Characteristics

= -1.5 V

VGS= 0 V

-0.2 V

-0.4 V

-0.6 V

-0.8 V

-1.0 V

VDS - Drain-Source Voltage (V)

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7-3

U421/423

Vishay Siliconix

TYPICAL CHARACTERISTICS (TA = 25_C UNLESS OTHERWISE NOTED)

Gate-Source Differential Voltage

VDG = 10 V
T

= 25_C

A

0.5
V

GS(off)

TA = -55_C

0.4

0.3

0.2

- Drain Current (mA)

D

I

125_C

0.1

Transfer Characteristics

= -1 V

25_C

VDS = 10 V

(mV)

GS2

V

-

GS1

V

100

10

vs. Drain Current

U423

U421

0

0-1-0.2 -0.4 -0.6 -0.8

100

V/ _C

m

()

GS2

10

V

-

t

D

GS1

V

D

1

10 100 1000

100

80

60

VGS - Gate-Source Voltage (V)

Voltage Differential with Temperature

vs. Drain Current

VDG = 10 V
DT

= 25 to 125_C

A

DT

= -55 to 25_C

A

U423

U421

I

- Drain Current (mA) ID - Drain Current (mA)

D

Circuit Voltage Gain vs. Drain Current

g

R

L

+

V

L

1 ) RLg

10 V

+

I

fs

os

D

A
Assume VDD = 15 V, VDS = 5 V
R

1

130

120

110

CMRR (dB)

100

90

80

5

4

3

10 100 1000

I

- Drain Current (mA)

D

Common Mode Rejection Ratio

vs. Drain Current

DV

CMRR = 20 log

D

V

DG

-

GS1 VGS2

DVDG = 10 - 20 V

5 - 10 V

10 100 1000

On-Resistance vs. Drain Current

V

= -1 V

GS(off)

40

- Voltage Gain

V

A

20

0

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7-4

V

GS(off)

-1.5 V

100 100010

I

- Drain Current (mA)

D

= -1 V

2

- Drain-Source On-Resistance ( Ω )
1

DS(on)

r

0

0.01 0.1 1
ID - Drain Current (mA)

Document Number: 70248

S-03180—Rev. D, 17-Feb-03

-1.5 V

TYPICAL CHARACTERISTICS (TA = 25_C UNLESS OTHERWISE NOTED)

U421/423

Vishay Siliconix

Common-Source Input Capacitance

vs. Gate-Source Voltage

2

VDS = 0 V

5 V

10 V

0-20-4 -8 -12 -16

VGS - Gate-Source Voltage (V)

Output Conductance vs. Drain Current

V

= -1 V

GS(off)

TA = -55_C

25_C

125_C

10 100 1000

ID - Drain Current (mA)

- Input Capacitance (pF)C
iss

- Output Conductance (µS)
g

1.6

1.2

0.8

0.4

0

1

0.8

0.6

0.4

0.2

os

0

f = 1 MHz

VDS = 10 V
f = 1 kHz

Common-Source Forward Transconductance

vs. Drain Current

= -1 V VDS = 10 V

TA = -55_C

25_C

f = 1 kHz

0.8

0.6

0.4

1

V

GS(off)

Common-Source Reverse Feedback

Capacitance vs. Gate-Source Voltage

1

f = 1 MHz

0.8
VDS = 0 V

0.6

10 V

0.4

0.2

- Reverse Feedback Capacitance (pF)C
rss

0

0-20-4 -8 -12 -16

5 V

VGS - Gate-Source Voltage (V)

Equivalent Input Noise Voltage vs. Frequency

50

VDS = 10 V

40

30

20

en - Noise Voltage nV / Hz

10

0

10 100 1 k 100 k10 k

ID = 30 mA

ID = 100 mA

f - Frequency (Hz)

On-Resistance and Output Conductance

vs. Gate-Source Cutoff Voltage

5

4

3

2

rDS @ ID = 10 mA, VGS = 0 V

@ VDS = 10 V, VGS = 0 V, f = 1 kHz

g

os

r

DS

g

os

20

os

16

- Output Conductance ( m

12

8

0.2

- Forward Transconductance (mS)

fs

g

0

10 100 1000

Document Number: 70248
S-03180—Rev. D, 17-Feb-03

125_C

ID - Drain Current (mA)

- Drain-Source On-Resistance ( Ω )
1

DS(on)

r

0

0-5-1 -2 -3 -4

V

- Gate-Source Cutoff Voltage (V)

GS(off)

S)g

4

0

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7-5

Legal Disclaimer Notice

Vishay

Disclaimer

All product specifications and data are subject to change without notice.

Vishay Intertechnology, Inc., its affiliates, agents, and employees, and all persons acting on its or their behalf
(collectively, “Vishay”), disclaim any and all liability for any errors, inaccuracies or incompleteness contained herein
or in any other disclosure relating to any product.

Vishay disclaims any and all liability arising out of the use or application of any product described herein or of any
information provided herein to the maximum extent permitted by law. The product specifications do not expand or
otherwise modify Vishay’s terms and conditions of purchase, including but not limited to the warranty expressed
therein, which apply to these products.

No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this
document or by any conduct of Vishay.

The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications unless
otherwise expressly indicated. Customers using or selling Vishay products not expressly indicated for use in such
applications do so entirely at their own risk and agree to fully indemnify Vishay for any damages arising or resulting
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Product names and markings noted herein may be trademarks of their respective owners.

Document Number: 91000 www.vishay.com
Revision: 18-Jul-08 1