Bulk Metal
®
Foil Technology Industrial Precision Resistors
with TCR of ± 4 ppm/°C
and Tolerance of ± 0.01 %
VSR Series
Vishay Foil Resistors
Document Number: 63009 For any questions, contact: foil@vishaypg.com www.foilresistors.com
Revision: 23-Mar-10 1
INTRODUCTION
Bulk Metal
®
Foil technology out performs all other resistor
technologies available today for applications that require
high precision and high stability.
This technology has been pioneered and developed by
VISHAY, and products based on this technology are the
most suitable for a wide range of applications.
Generally Bulk Metal Foil technology allows us to produce
customer orientated products designed to satisfy challenging
and specific technical requirements.
The VSR series of resistors is a low cost version of the well
established S series of resistors. These resistors are made
of foil elements so all of the inherent performance of foil is
retained. They do not however, have the same TCR or
tolerance ranges (see table 1 for details). These products
find a wide range of usage in high end stereo equipment and
some grades of test and measurement equipment.
Standoffs are dimensioned to provide a minimum lead
clearance of 0.010" between the resistor body and the
printed circuit board, when the standoffs are seated on the
board. This allows for proper cleaning after the soldering
process.
Our applications engineering department is available to
advise and to make recommendations for non standard
technical requirements and special applications, please
contact us.
FEATURES
• Temperature coefficient of resistance (TCR)
(1)
:
± 4 ppm/°C (0 °C to + 60 °C)
± 8 ppm/°C (- 55 °C to + 125 °C, + 25 °C ref.)
• Resistance range: 0.5 Ω to 1 MΩ (higher or lower
values of resistance are available)
• Vishay Foil resistors are not restricted to standard values,
we can supply specific “as required” values at no extra cost
or delivery (e.g. 1K2345 vs. 1K)
• Tolerance: to ± 0.01 % (100 ppm)
• Load life stability: to ± 0.005 % at 70 °C, 2000 h at rated
power
• Electrostatic discharge up to 25 000 V
• Non inductive, non capacitive design
• Rise time: 1 ns effectively no ringing
• Current noise: - 40 dB
• Thermal EMF: 0.05 µV/°C typical
• Voltage coefficient: < 0.1 ppm/V
• Inductance: 0.08 µH
• Matched sets available
• Terminal finish: lead (Pb)-free
tin/lead alloy
• Prototype samples available from 72 h. For more
information, please contact foil@vishay.com
• For better performances please review the S Series
datasheet
Note
(1)
For values below 50 Ω please contact application engineering
APPLICATIONS
• Industrial
• Medical
• Audio (high end stereo equipment)
• Test and measurement equipment
• Precision amplifiers
* Pb containing terminations are not RoHS compliant, exemptions may apply
FIGURE 1 - POWER DERATING CURVE
200 %
175 %
150 %
125 %
100 %
75 %
50 %
25 %
0
- 75 - 50 - 25 0 + 25 + 50 + 75 + 100 + 125 + 150 + 175 + 200
Ambient Temperature (°C)
Percent of Rated Power at + 125 °C
- 55 °C + 70 °C
Double Rated Power
Rated Power
Δ
Safe operation
for < 150 ppm
R after 2000
hours load-life.
FIGURE 2 - TRIMMING TO VALUES
(Conceptual Illustration)
Mutual Inductance
Reduction due
to Change in
Current Direction
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
