Document Number: 63023

For any questions, contact: foil@vishay.com

www.vishay.com

Revision: 19-Feb-08

2

VCS1625

High Precision Foil Surface Mount Current Sensing

Chip Resistors with TCR of ± 2 ppm/°C and

Load Life Stability of ± 0.02 %

Vishay Foil Resistors

Note

•

Measurement error 0.001 R

FIGURE 2 - DIMENSIONS in inches (millimeters)

INCHES

MILLIMETERS

L

0.250 ± 0.010

6.35 ± 0.25

H

0.160 ± 0.010

4.06 ± 0.25

W

0.040 maximum

1.02 maximum

A

0.080 ± 0.005

2.03 ± 0.13

B

0.040 ± 0.010

1.02 ± 0.25

L

H

W

A

B

I2

I1

E1

E2

Solder Pad Layout

Top View

Bottom View

Mounting

Pads (4)

0.260

(6.60)

0.070

(1.78)

FIGURE 1 - TRIMMING TO VALUES

(Conceptual Illustration)

Mutual Inductance

Reduction due

to Opposing

Current in

Adjacent Lines

Current Path

Before Trimming

Note: Foil shown in black, etched spaces in white

Interloop Capacitance

Reduction in Series

Trimming Process

Removes this Material

from Shorting Strip Area

Changing Current Path

and Increasing

Resistance

Current Path

After Trimming

FIGURE 4 - TYPICAL TCR CURVE

+ 75

+ 150

+ 100

+ 50

0

- 50

- 100

- 150

- 200

Ambient Temperature (°C)

R

(ppm)

± 2 ppm/°C (+ 25 °C reference)

+ 100

+ 125

- 25

0+ 25

+ 50

- 50

TABLE 2 - PERFORMANCE SPECIFICATIONS

TEST

MIL-PRF-55342

ΔR LIMITS

TYPICAL

ΔR LIMITS

MAXIMUM

ΔR LIMITS

Thermal Shock 5 x (- 65 °C to + 150 °C)

± 0.10 %

± 0.005 % (50 ppm)

± 0.01 % (100 ppm)

Low Temperature Operation

± 0.10 %

± 0.005 % (50 ppm)

± 0.01 % (100 ppm)

Short Time Overload

± 0.10 %

± 0.005 % (50 ppm)

± 0.02 % (200 ppm)

High Temperature Exposure

± 0.10 %

± 0.01 % (100 ppm)

± 0.02 % (200 ppm)

Resistance to Soldering Heat

± 0.2 %

± 0.01 % (100 ppm)

± 0.03 % (300 ppm)

Moisture Resistance

± 0.20 %

± 0.01 % (100 ppm)

± 0.03 % (300 ppm)

Load Life 2000 h at 70 °C: Rated Power On Ceramic PCB

± 0.5 %

± 0.02 % (200 ppm)

± 0.04 % (400 ppm)