VCS1610Z (Kelvin Connection)
Vishay Foil Resistors
High Precision Foil Surface Mount Current Sensing Chip
Resistors with TCR of ± 0.2 ppm/°C, Load Life Stability of ± 0.015 %,
ESD Immunity up to 25 kV and Fast Thermal Stabilization
FEATURES
Temperature coefficient of resistance (TCR):
± 0.2 ppm/°C typical (- 55 °C to + 125 °C,
+ 25 °C ref.) (see table 1)
Resistance range: 0.3
to 10
Resistance tolerance: to ± 0.5 %
Load life stability:
± 0.015 % at 70 °C, 2000 h at rated power
Power rating: 0.25 W at + 70 °C
Vishay Foil resistors are not restricted to standard values;
specific “as required” values can be supplied at no extra
cost or delivery (e.g. 0.345
vs. 0.3
)
Electrostatic discharge (ESD) at least to 25 kV
Thermal stabilization time < 1 s (nominal value
achieved within 10 ppm of steady state value)
Short time overload < 0.005 %
Non-inductive, non-capacitive design
Thermal EMF: 0.05 µV/°C typical
Current noise: 0.010 µV
RMS
/V of applied voltage
(< - 40 dB)
Rise time: 1 ns effectively no ringing
Voltage coefficient: < 0.1 ppm/V
Non inductive: < 0.08 µH
Non hot spot design
Prototype quantities available in just 5 working days
or sooner. For more information, please contact
foil@vishaypg.com
INTRODUCTION
The Z-foil technology provides a significant reduction of the
resistive component’s sensitivity to ambient temperature
variations (TCR) and applied power changes (PCR).
Designers can now guarantee a high degree of stability and
accuracy in fixed-resistor applications using solutions based
on Vishay‘s Foil Resistors revolutionary Z-foil technology.
Model VCS1610Z is a surface mount chip resistor designed
with 4 pads for Kelvin connection. Utilizing Vishay’s Bulk
Metal® Z-foil as the resistance element, it provides
performance capabilities far greater than other resistor
technologies can supply in a product of comparable size.
± 0.2 ppm/°C typical TCR (- 55 °C to + 125 °C,+ 25 °C ref.)
removes errors due to temperature gradients.
This small device dissipates heat almost entirely through the
pads so surface mount users are encouraged to be generous
with the board’s pads and traces.
Our application engineering department is available to
advise and to make recommendations. For non-standard
technical requirements and special applications, please
contact us.
Percent of Rated Power
TABLE 1 - TOLERANCE AND TCR VS.
RESISTANCE VALUE
(- 55 °C to + 125 °C, + 25° Ref.)
VALUE
()
0R5 to 10R
0R3 to 0R5
Note
TOLERANCE
TYPICAL TCR
AND
MAX. SPREAD
(ppm/°C)
± 0.2 ± 4.8
± 0.2 ± 9.8
FIGURE 1 - POWER DERATING CURVE
(1)
- 55 °C
100
75
50
25
0
- 75
+ 70 °C
0.5 %, 1 %
0.5 %, 1 %
- 50
- 25
0
+ 25
+ 50
+ 75 + 100 + 125 + 150 + 175
Ambient Temperature (°C)
• Tighter tolerances and higher values are available. Please
contact application engineering
foil@vishaypg.com
Note
(1)
Power rating: 0.25 W at + 70 °C
* TERMINATIONS
Tin/lead plated
Two options of lead (Pb)-free leads available:
–
Gold plated
–
Tin plated
* Pb containing terminations are not RoHS compliant, exemptions may apply
Document Number: 63226
Revision: 6-Jul-12
For any questions, contact:
foil@vishaypg.com
www.vishayfoilresistors.com
1
VCS1610Z (Kelvin Connection)
Vishay Foil Resistors
Why use Kelvin connections?
Four-terminal connections or Kelvin connections are
required in these low ohmic value resistors to measure a
precise voltage drop across the resistive element. The
4-terminal configuration eliminates the IR-drop error voltage
that would be present in the voltage sense leads if a standard
two-terminal resistor were used.
In current sense resistors the contact resistance and the
terminations resistance may be greater than that of the
resistive element itself so lead connection errors can be
significant if only two terminal connections are used.
Why is the VCS1610Z vital in avoiding Thermal EMF
(parasitic effect)?
When two dissimilar metals are heated, a parasitic voltage is
generated and creates a DC-offset error. This voltage is
proportional to a temperature difference between either end
of the pair of conductors. This phenomenon is called a
Thermal Electro-motive Force (Thermal EMF), or
thermocouple effect. Thermal EMF is an important
consideration in low ohmic current sensing resistors used
mostly in DC circuits. The VCS1610Z is the ideal solution to
minimize the effect of thermal EMF through the use of
appropriate materials between the resistive layer and the
terminations.
Should I be concerned about the impact of ESD on my
resistor?
Electrostatic Discharge (ESD) is known to produce
catastrophic failures in thin-film and thick-film (cermet)
resistors at only 3000 V. On the other hand, the Bulk Metal®
Foil resistor withstands ESD events up to 25 kV because its
thicker resistance element and greater metallic mass afford
much higher energy-handling capability than either the much
thinner thin-film resistor or the sparse, non-homogeneous
metallic content of the thick film resistor.
Should I be concerned about stability?
In order to select the resistor technology most appropriate to
the application, a designer must take into account all normal
and extraordinary stresses the resistor will experience in the
application. In addition, the designer must consider the cost
and reliability impact involved when it becomes necessary to
add costly additional compensating circuitry when
inadequate resistors are selected. The stability of Bulk
Metal® Foil resistors, together with the advantages already
mentioned, as well as the other basic advantages apparent
in their specifications will not only provide unequalled
performance in the circuit but will eliminate all the costs
associated with extra compensation circuitry.
With VCS1610Z, only a minimal shift in resistance value will
occur during its entire lifetime. Most of this shift takes place
during the first few hundred hours of operation, and virtually
no change is noted thereafter.
FIGURE 2 - TRIMMING TO VALUES(Conceptual
Illustration)*
Current Path
Before Trimming
Current Path
After Trimming
Trimming Process
Removes this Material
from Shorting Strip Area
Changing Current Path
and Increasing
Resistance
NOTE:
Foil shown in black, etched spaces in white
* To acquire a precision resistance value, the Bulk Metal
®
Foil chip is
trimmed by selectively removing built-in “shorting bars.” To increase the
resistance in known increments, marked areas are cut, producing
progressively smaller increases in resistance. This method eliminates
the effect of “hot spot” and assures the long term stability of the Foil
chips.
www.vishayfoilresistors.com
2
For any questions, contact:
foil@vishaypg.com
Document Number: 63226
Revision: 6-Jul-12
VCS1610Z (Kelvin Connection)
Vishay Foil Resistors
FIGURE 3 - DIMENSIONS
in inches (millimeters)
L
4 Mounting
A
Pads
(1)
I
2
E
1
0.110
(2.794)
0.020
(0.508)
0.060
(1.524)
I
1
R
E
2
B
H
W
E
2
I
1
0.200
(5.08)
E
1
I
2
Top View
Bottom View
Solder Pad Layout
Electrical Schematic
Note
(1)
I and E mounting pads are interchangeable
INCHES
L
H
W
A
B
0.160 ± 0.010
0.100 ± 0.010
0.040 maximum
0.045 ± 0.005
0.030 ± 0.010
MILLIMETERS
4.06 ± 0.25
2.54 ± 0.25
1.02 maximum
1.14 ± 0.13
0.76 ± 0.25
FIGURE 4 - TYPICAL RESISTANCE/TEMPERATURE CURVE
+ 500
+ 400
+ 300
+ 200
+ 100
ΔR
0
R
(ppm)
- 100
- 200
- 300
- 400
- 500
- 55
- 25
0
+ 25
+ 60 + 75
+ 100 + 125
- 0.16 ppm/°C
0.05 ppm/°C
- 0.1 ppm/°C
0.1 ppm/°C
0.14 ppm/°C
0.2 ppm/°C
Ambient Temperature (°C)
TABLE 2 - PERFORMANCE SPECIFICATIONS
TEST
Thermal Shock 5 x (- 65 °C to + 150 °C)
Low Temperature Operation, - 65 °C, 45 min at P
nom
Short Time Overload, 6.25 x Rated Power, 5 sec
High Temperature Exposure, + 150 °C, 100 h
Resistance to Soldering Heat, +245°C for 5 sec,+235°C for 30 sec
Moisture Resistance
Load Life Stability + 70 °C for 2000 h at Rated Power
Note
* Measurement error 0.001 R
MIL-PRF-55342
R
LIMITS
± 0.10 %
± 0.10 %
± 0.10 %
± 0.10 %
± 0.2 %
± 0.2 %
± 0.5 %
TYPICAL
R
LIMITS*
± 0.005 % (50 ppm)
± 0.005 % (50 ppm)
± 0.005 % (50 ppm)
± 0.01 % (100 ppm)
± 0.01 % (100 ppm)
± 0.01 % (100 ppm)
± 0.015 % (150ppm)
Document Number: 63226
Revision: 6-Jul-12
For any questions, contact:
foil@vishaypg.com
www.vishayfoilresistors.com
3
VCS1610Z (Kelvin Connection)
Vishay Foil Resistors
FIGURE 5 - HIGH TEMPERATURE EXPOSURE
High Temperature Exposure
VCS1610Z, 1R; +150°C, 100 hrs ; n=10
300
250
200
150
100
50
R
(ppm)
0
-50
-100
-150
-200
-250
-300
Resistor Serial Number
0
1
2
3
4
5
6
7
8
9
10
FIGURE 6 - LOAD LIFE
LOAD LIFE
VCS1610Z, 1R ; 0.25W @ +70C, 2000 hrs ; n=15
300
250
200
150
100
50
R
(ppm)
0
-50
-100
-150
-200
-250
-300
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Time (hrs)
www.vishayfoilresistors.com
4
For any questions, contact:
foil@vishaypg.com
Document Number: 63226
Revision: 6-Jul-12
VCS1610Z (Kelvin Connection)
Vishay Foil Resistors
FIGURE 7 - LOW TEMPERATURE OPERATION
Low Temperature Operation
VCS1610Z 0R2; -65°C, 45 min at 0.25W, n=10
300
250
200
150
100
R
(ppm)
50
0
-50
-100
-150
-200
-250
-300
Resistor Serial Number
0
1
2
3
4
5
6
7
8
9
10
FIGURE 8 - SHORT TIME OVERLOAD
Short Time Overload
VCS1610Z 0R2; 6.25 x Rated Power, 5 sec ; n=10
300
250
200
150
100
50
R
(ppm)
0
-50
-100
-150
-200
-250
-300
Resistor Serial Number
0
1
2
3
4
5
6
7
8
9
10
www.vishayfoilresistors.com
5
For any questions, contact:
foil@vishaypg.com
Document Number: 63226
Revision: 6-Jul-12