300144, 300145
Vishay Foil Resistors
Bulk Metal
®
Foil Technology High Precision Voltage Divider
Resistors with TCR Tracking to 0.5 ppm/°C and
Tolerance Match to 0.005 % (50 ppm)
FEATURES
Temperature coefficient of resistance (TCR)
absolute: ± 2 ppm/°C typical
(- 55 °C to + 125 °C, + 25 °C ref.)
TCR tracking: 0.5 ppm/°C
Tolerance: absolute and matching to 0.005 %
(50 ppm)
Power rating: 0.2 W at 70 °C, for the entire resistive
element R
1
and R
2
, divided proportionally between the two
values
Load life ratio stability: < 0.005 % (50 ppm) 0.2 W at 70 °C
for 2000 h
Maximum working voltage: 200 V
Resistance range: 100R to 20K per resistive element
Vishay Foil resistors are not restricted to standard
values/ratios; specific “as requested” values/ratios can be
supplied at no extra cost or delivery (e.g. 1K2345 vs. 1K)
Electrostatic discharge (ESD) up to 25 000 V
Non-inductive, non-capacitive design
Rise time: 1 ns effectively no ringing
Thermal stabilization time < 1 s (nominal value achieved
within 10 ppm of steady state value)
Current noise: 0.010 µV
RMS
/V of applied voltage (< - 40 dB)
Thermal EMF: 0.05 µV/°C typical
Voltage coefficient: < 0.1 ppm/V
Non inductive: < 0.08 µH
Non hot spot design
Terminal finish: lead (Pb)-free or tin/lead alloy
Compliant to RoHS directive 2002/95/EC
Prototype quantities available in just 5 working days
or sooner. For more information, please contact
foil@vishaypg.com
For better performances see 300144Z, 300145Z (Z-Foil)
datasheet
INTRODUCTION
Why tight tolerance is important?
Why do users employ tight tolerance resistors? A system or
a device or one particular circuit element must perform for a
specified period of time and at the end of that service period
it must still be performing within specifications.
During its useful life it may have been subjected to some
hostile service conditions and it is no longer within purchased
tolerance.
What is ratio?
The ratio tolerances available in a divider are variable and
dependent on resistor technology. Bulk Metal
®
foil provides
the tightest ratio tolerance available.
The tight resolution capability and overall stability of foil
resistors permit adjustment within the divider to ratio not
available with other technologies. Ratios in network form, in
a common package have a better chance of holding tight
tolerances than those formed in a discrete matched set by
sorting.
Molded foil 300144, 300145 resistors can be provided in a
tolerance as tight as 0.005 %. Theoretically, ratios such as
these can be made initially with other resistor technologies.
However, less stable products will not hold these tight ratios
tolerances over time and applied stresses like voltage and
temperature.
Vishay Foil Resistors (VFR) Bulk Metal foil dividers/networks
300144, 300145 hold their ratio tolerances under defined
circumstances. Networks with tight ratio tolerances and
controlled tracking extend the useful life of equipment,
whether expressed as mean-time-between-failures (MTBF)
or service periods to recalibration or end-of-life-cycle.
How to avoid thermal EMF?
When the resistor’s terminals and the resistive element are
made of dissimilar metals and two junctions are at a different
temperature, a voltage is produced which is called “thermal
EMF”.
The level of voltage output is a function of the metals
involved and the differential temperature. The voltage
produced is either positive or negative depending on which
junction is considered as a reference point. Virtually all
resistive products have these metallic junctions. It is
presumed they will eventually be terminated to copper as a
final metallic combination and therefore copper is used as a
typical reference material.
300144, 300145 have the lowest thermal EMF’s because all
junctions have low microvolts outputs. Moreover,
construction of the resistive element is such that the input
and output junctions of the resistor are so close that the
temperature gradients between then is highly unlikely. These
design factors produce a divider with very low thermal EMF.
Our application engineering department is available to
advise and make recommendations. For non-standard
technical requirements and special applications. Please
contact us.
APPLICATIONS
Instrumentation amplifiers
Bridge networks
V
1
Differential amplifiers
V
2
Military
Space
Medical
Automatic test equipment
Down-hole (high temperature)
R
2
R
1
R
3
R
4
-
+
V
out
300144
300145
* Pb containing terminations are not RoHS compliant, exemptions may apply
Document Number: 63045
Revision: 16-Sep-13
For any questions, contact:
foil@vishaypg.com
www.vishayfoilresistors.com
1
300144, 300145
Vishay Foil Resistors
TABLE 1A - MODELS 300144 AND 300145
SPECIFICATIONS
RESISTANCE
VALUES
500
to 20 k
100
to < 500
ABSOLUTE
TOLERANCE
± 0.005 %
± 0.01 %
ABSOLUTE TCR
(- 55 °C to + 125 °C,
+ 25 °C ref.)
TYPICAL AND MAX.
SPREAD
± 2 ppm/°C ± 3 ppm/°C
TABLE 1B - MODELS 300144 AND 300145
SPECIFICATIONS
RESISTANCE
RATIO
1:1
> 1:1 to 4:1
> 4:1 to 10:1
> 10:1
TOLERANCE
MATCH
0.005 %
0.01 %
TCR TRACKING MAX.
0.5 ppm/°C
1.0 ppm/°C
1.5 ppm/°C
2.0 ppm/°C
Note
• See table 3 for additional established ratios
FIGURE 1 - TRIMMING TO VALUES
(conceptual illustration)
Interloop
Capacitance
Reduction
in Series
Mutual
Inductance
Reduction due
to Opposing
Current in
Adjacent Lines
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
FIGURE 2 - STANDARD PRINTING AND DIMENSIONS
in inches (millimeters)
Model 300144 and Schematic
(2)
0.295
(7.49)
VFR
9825
300144
0.1
(2.54)
Match
Tolerance
6
5
Model 300145 and Schematic
(2)(3)
0.375
(9.53)
4
0.2
(5.08)
10K000
0.01%
10K000
Date Code
Model No.
0.015 ± 0.005
(0.38 ± 0.13)
0.025 ± 0.005
(0.64 ± 0.13)
0.320
(8.13)
R
1
R
2
6
5
4
1
R1
Indicator
R
4
1
2
3
Date Code
Model No.
VFR
0730
300145
0.375
(9.53)
R
3
0.015 ± 0.005
(0.38 ± 0.13)
10K000
0.01%
10K000
0.75
(1)
(19.05)
R
1
0.75
(1)
(19.05)
Match
Tolerance
R
2
Dimensional Tolerance: ± 0.010" (0.25)
0.1 (2.54)
(1)
0.025 ± 0.005
(0.64 ± 0.13)
1
2
3
(2)
(3)
Lead wires: #22 AWG solder coated copper,
0.75" minimum length
Each divider pair consists of two resistors on one
single chip
For model 300145 the 2 chips are independent
and with no special relationship from chip to chip
1
2
3
0.1 (2.54)
www.vishayfoilresistors.com
2
For any questions, contact:
foil@vishaypg.com
Document Number: 63045
Revision: 16-Sep-13
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Vishay Precision Group, Inc.
Disclaimer
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Copyright Vishay Precision Group, Inc., 2014. All rights reserved.
Document No.: 63999
Revision: 15-Jul-2014
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