VSMF Series (1206, 2010, 2512)
Vishay Foil Resistors
TheFirstHighPercisionBulkMetal®FoilSurface-MountChipResistorwithFlexibleTerminationsC,TRof2ppm/°CandLoadLfei Stablityof0.01%(100ppm)
The First High Precision Bulk Metal® Foil Surface-Mount
Chip Resistor with Flexible Terminations,
TCR of 2 ppm/°C and Load Life Stability of 0.01% (100 ppm)
FEATURES
•ꢀTemperatureꢀcoefficientꢀofꢀresistanceꢀ(TCR):ꢀ
2.0 ppmꢀ/C typical (ꢁ––/C to ꢂ12–/C, ꢂ2–/C ref.)
(see Table 1)
•ꢀResistanceꢀrange:ꢀ10ꢀΩꢀtoꢀ125ꢀkΩꢀ(forꢀhigherꢀandꢀlowerꢀ
values, please contact Application Engineering)
Top View
•ꢀResistanceꢀtolerance:ꢀtoꢀ±0.01%ꢀ
•ꢀPowerꢀrating:ꢀtoꢀ400ꢀmWꢀatꢀ+70°C
•ꢀLoadꢀlifeꢀstability:ꢀtoꢀ±0.01%ꢀatꢀ70°C,ꢀ2000ꢀhꢀatꢀ
rated power
•ꢀStrain relief construction by flexible terminations
•ꢀVishayꢀFoilꢀresistorsꢀareꢀnotꢀrestrictedꢀtoꢀstandardꢀ
values; specific “as required” values can be supplied at
noꢀextraꢀcostꢀorꢀdeliveryꢀ(e.g.ꢀ1K2345ꢀvs.ꢀ1K)
•ꢀThermalꢀstabilizationꢀtimeꢀ<ꢀ1ꢀsꢀ(nominalꢀvalueꢀachievedꢀ
within 10 ppm of steady state value)
•ꢀElectrostaticꢀdischargeꢀ(ESD):ꢀatꢀleastꢀtoꢀ25ꢀkV
•ꢀThermalꢀEMF:ꢀ0.05ꢀμV/°C
•ꢀNonꢀinductive,ꢀnonꢀcapacitiveꢀdesign
•ꢀRiseꢀtime:ꢀ1ꢀnsꢀeffectivelyꢀnoꢀringing
•ꢀCurrentꢀnoise:ꢀ0.010ꢀµVRMSꢀV of applied voltage
(<–40ꢀdB)
INTRODUCTION
Vishay Foil Resistors’ new VSMF model is targeted for
applications that are prone to high thermal stress or
mechanical stress; it features low TCR, excellent load life
stability, tight tolerance, excellent shelf-life stability, low
current noise, high speed, and low voltage coefficient—all
in the same resistor.
It is well known that chips of 1206 dimensions and
larger can occasionally develop cracks and even fall off
the printed circuit board, especially when exposed to
temperature cycling. These instances are due to stress-
inducing mishandling of the PC board (e.g., bending during
assembly), excess thermal gradients, or thermal shock.
The latter two can be divided into two categories:
1. Thermal stress induced by changes in ambient
temperature. Here, different coefficients of expansion
induce mechanical stress as PCB compression
imposes tension on the resistor (or vice versa).
2. Thermal stress caused by internal heat generation
(load). Here, power dissipation within the resistor
generates temperature differentials between the
resistor and the PCB, resulting in variable stresses.
•ꢀVoltageꢀcoefficientꢀ<0.1ꢀppm/V
•ꢀNonꢀinductive:ꢀ<0.08ꢀµH
•ꢀNonꢀhotꢀspotꢀdesign
•ꢀPrototypeꢀquantitiesꢀavailableꢀinꢀjustꢀ5ꢀworkingꢀdaysꢀorꢀ
sooner. For more information, please contact us.
•ꢀTerminalꢀfinish:ꢀleadꢀ(Pb)-freeꢀorꢀtin/leadꢀalloy*
Note:
Stress cycling due to these two phenomena causes
material fatigue and cracks.
*
Pb containing terminations are not RoHS compliant,
exemptions may apply.
Vishay Foil Resistors’ new VSMF series of surface-mount
chip resistors feature flexible terminations to prevent
cracking of the body of the chip or delamination from the
board, especially in resistors with high length-to-width
aspect ratios.
TABLE 1—TOLERANCE AND TCR VS.
RESISTANCE VALUE(1)
(-––/C to ꢂ12–/C, ꢂ2–/C Ref.)
For applications with high thermal stresses, designers
typically use molded resistors with flexible terminations.
These are larger than chip resistors and require more real
estate on the PCB. Vishay Foil Resistors has developed
and patented a solution which permits direct replacement
of standard chips by chips with flexible terminations.
RESISTANCE
VALUE (Ω)
TOLERANCE
(%)
TYPICAL TCR AND
MAX. SPREAD (ppm/°C)
2–0 to 12–K
100ꢀtoꢀ<250
50ꢀtoꢀ<100
25ꢀtoꢀ<50
0.01
0.02
0.0–
0.1
2
2
2
2
3
3
The Vishay Foil Resistors’ application engineering
department is available to advise and make
recommendations.
±2ꢀ±4
10ꢀtoꢀ<25
0.2–
2 6
Note
For non-standard technical requirements and special
applications, please contact foil@vishaypg.com.
(1)
For tighter performances and lower values, please contact
Application Engineering.
Document No.: 63177
Revision: 07-Nov-2011
For questions, contact foil@vishaypg.com
www.vishayfoilresistors.com
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