About VFR Resistors
VFR Resistors' ultra precision VPG Bulk Metal® Foil resistor products provide extremely low temperature coefficient of resistance (TCR) and exceptional long-term stability through temperature extremes. The VFR Resistors portfolio comprises products in a variety of resistor configurations and package types to meet the needs of a wide range of applications: discrete resistors and resistor networks in surface mount and through-hole (leaded) configurations; customized chip resistor networks; precision trimming potentiometers; and discrete chips for use in hybrid circuits.
In addition to being a VPG distributor, Charcroft are also a VPG-Approved Precision Centre, manufacturing and delivering 0.005%+ radial and 0.01%+ surface mount resistors based on VPG's Bulk Metal® Foil resistor technology. We also manufacture BS and CECC approved, and commercial multilayer ceramic capacitors (MLCCs) down to 1% tolerance. COTS and CECC-release precision resistors are available with optional Precision Express delivery of 5 to 15 days. All Precision Express products can be mounted on "Any-Quantity" tape-and-reels or bandoliers.
Technical Resources
| Technical Resource | Download |
|---|---|
| VPG Foil Resistors Flyer | Download |
| Advantages of Precision Resistance Networks in Sensitive Applications | Download |
| Bulk Metal Foil Resource Guide | Download |
| Bulk Metal Z Foil Technical Notes | Download |
| Effects of Short Time Overload Precision Resistors | Download |
| Foil Resistors in Action | Download |
| Foil Resistors Military & Space Applications Catalogue | Download |
| Introduction to High Precision Resistors | Download |
| List of Mil-Spec Released Foil Resistors | Download |
| How to Select Resistors for Precision Applications | Download |
| Non-Linearity of Resistance Temperature Characteristic | Download |
| Obsolescence Counterfeiting & COTS: Understanding the Consequences | Download |
| Predicting Drift in Foil Resistors | Download |
| Precision Resistors for Energy, Transportation, and High-Temperature Applications | Download |
| Price Trade-Off: Cost, Price, Risk when Selecting a Precision Resistor | Download |
| Precision Resistors for Electric Aircraft & Fly-By-Wire | Download |
| Pulse Load Capability of Precision Chip Resistors | Download |
| Selecting Resistors for Pre Amp Amplifier & Other High End Applications | Download |
| Solving Data Transmission Problems | Download |
| Vishay Foil Resistors High Temperature Catalogue | Download |
| Vishay Foil Resistors Design and Selector Guide for High-Precision Resistors | Download |
| MS0178 Charcroft Disty AMS Flyer HiRes | Download |
| Product Overview High Precision | Download |
| PT0901 RTD Simulators | Download |
| VPG Foil Resistors Brochure | Download |
Product Range
Bulk Metal® Foil VPR220Z in Cryogenics
VPG Foil Resistors’ Bulk Metal® Foil VPR220Z in Cryogenics
Cryogenics require structural integrity capable of withstanding extreme thermal cycling without hindering performance or worse, damaging the unit. Applications that must operate with unquestioned dependability and precision at cryogenic temperatures require special components that have the inherent robustness to perform successfully.
Watch what happens to VPG Foil Resistors’ Bulk Metal® Foil VPR220Z when exposed to -200°C!
Product Documentation
Ultra-high precision z foil current sense resistors for space applications
VPG Foil Resistors has introduced industry-exclusive ultra-high precision current sense resistors. These components incorporate a unique design consisting of VPG’s own proprietary Bulk Metal Z Foil resistive technology, along with a four-terminal Kelvin connection design, for precision current sensing and temperature stability.
The unique Bulk Metal® Foil resistor technology is universally recognized for its long-term consistency and reliability, which makes it the ideal resistive solution for space applications. This technology is highlighted by an advanced manufacturing technique of balancing thermo-mechanical forces between a Bulk Metal Foil alloy and an engineered ceramic substrate resulting in unparalleled low Temperature Coefficient of Resistance (TCR), long-term stability, non-inductance, ESD insensitivity, low capacitance, fast thermal stabilization, and low noise. When this resistive element is combined with a 4 terminal Kelvin connection configuration, the result is an outstanding Z Foil current sense resistor which generates a highly precise voltage directly proportional to measured current levels for efficient control and precise measurements.
Product Documentation
CSM3637F Four-Terminal Bulk Metal Z Foil High-Precision Current Sense Resistor
New VPG Foil Resistors CSM3637F Four-Terminal Bulk Metal® Z Foil High-Precision Current Sense Resistor Combines Excellent Load-Life Stability With Low TCR for Applications to 3W
VPG Foil Resistors, a Vishay Precision Group, Inc. product group, have announced that its Vishay Foil Resistors brand has introduced a new current sense resistor for the medical, energy, military and aerospace markets. The high-precision, surface-mount, four-terminal CSM3637F current sense resistor is an industry first due to its size in combination with an improved load-life stability of ±0.02% at +70°C for 2,000 hours with a low TCR of ±5 ppm/°C max from -55°C to +125°C and a high power rating up to 3W.
The CSM3637F resistor is optimized for high-precision current sensing applications in switching linear power supplies, power amplifiers, power management systems, feedback circuits, measurement instrumentation and automatic test equipment. The device features a resistance range from 50 mΩ to 200 mΩ with any conceivable ohmic value within this range - out to six digits - available with no additional cost or lead time effect. The resistor provides ESD immunity to 25 kV or more, power coefficient of resistance (ΔR due to self-heating) of 5 ppm/W at rated power, and tight tolerance of ±0.1%.
The CSM3637F resistor’s unique combination of Bulk Metal® Z Foil Technology and a four-terminal Kelvin connection results in a significant reduction of the device’s sensitivity to applied power changes such as power coefficient of resistance (PCR) and thermal resistance, while its low TCR reduces errors due to temperature changes. Short-time overload tests applying 10W power for 5 seconds on the device were passed with a maximum ΔR of 0.01%.
“The CSM3637F resistor is the ideal solution for applications up to 3 W where the emphasis is on accuracy and repeatability under stressed conditions and swift current changes, such as current power supplies, deflection amplifiers, electron microscopes, electron beam systems and force-balanced scales,” said Jacky Acoca, sales and marketing director, VPG Foil Resistors. “Such products require a precise voltage proportional to the current, and the CSM3637F resistor delivers with its unique design, low TCR, and excellent load-life stability.”
“The stability of Bulk Metal® Z Foil resistors, as well as the other basic advantages apparent in Bulk Metal® Z Foil specifications, will not only provide unequalled performance in the circuit, but will eliminate all the costs associated with extra compensation circuitry,” added Hero Faierstain, application engineering senior manager, Vishay Foil Resistors. “With the CSM3637F, 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.”
Product Documentation
FRSG Series - Ultra High-Precision Foil Wraparound Surface Mount Chip Resistor with Gold Plated Terminals for High Temperature Applications up to +225°C
Optimised for harsh and high-temperature applications, these resistors can be trimmed to any ohmic value, up to six digits, within the resistance range on a standard leadtime.
- TCR: 2.5ppm/°C maximum from -55°C to 200°C (+25°C ref.)
- Resistance range: 10Ω to 125kΩ
- Tolerance: to ±0.01%
- Working power with ceramic PCB:
- 750mW at +70°C
- 300mW at +200°C
- Long-term stability: 0.1% at 225°C for 1000h, no power
- Load-life stability: ±0.1% at 200°C for 2000h, working power
- Gold-plated terminals in case sizes from 0603 to 2512
Product Documentation
Ultra High Precision Z1 Foil Technology Flip Chip Resistor for Load Life Stability
The FRFC is based on the new generation Z1 Foil Technology of the Bulk Metal® Precision Foil resistor elements by VPG, which makes these resistors virtually insensitive to destabilizing factors.
VPG Foil Resistors announced today that its Vishay Foil Resistors brand has released the FRFC Series, a new family of ultra-high-precision flip chip resistors based on the market-leading Z1 Foil Technology. The FRFC Series delivers remarkable load life stability of 50 ppm, better withstanding to higher temperatures, and better moisture resistance than previous-generation foil resistors. Compared to surface-mount chips with wraparound terminations, the flip chip configuration of the FRFC Series provides PCB space savings of more than 35%.
The FRFC Series owes its high-performance characteristics to a resistive element based on Z1 Foil Technology, a solid alloy that is matched to the ceramic substrate with polyimide bonding to enable a uniform thickness of the bond line, superior adhesion strength, and improved resistance to moisture. Virtually insensitive to destabilizing factors, the FRFC Series features a temperature coefficient of resistance (TCR) or ±0.2 ppm/°C (−55°C to +125°C, +25°C ref), ESD immunity to 25kV or more, and noise-free operation. Its power rating is 750mW at +70°C, a 25% improvement over the VFCP Series, which is already a superior product in the high-precision resistors industry. The FRFC Series flip-chip resistors are offered in the 0805, 1206, 1506, 2010, and 2512 case sizes, with power TCR (ΔR due to self-heating) of 5ppm at rated power and tight tolerances to ±0.01%.
“The FRFC Series devices provide designers with the most stable resistors available today — allowing them to achieve new benchmark levels in performance,” said Jacky Acoca, Vishay Foil Resistors Director of Sales and Marketing. “In addition to saving on board space, the devices’ flip-chip terminations increase reliability by providing better strain relief to eliminate cracked substrates and board delamination.”
The FRFC Series flip chip resistors are optimized for a wide range of high-precision industrial, telecommunications, medical, and laboratory applications, including bridge networks, gyro navigational controls, pressure sensors, standards and decade boxes, process controls, weighing systems, electron beams, and automatic test equipment. The new resistors offer a resistance range from 5W to 125kW with any conceivable ohmic value within this range — out to six digits — available with no additional cost or lead time effect. They feature a rise time of 1.0 ns with effectively no ringing; a thermal stabilization time of < 1s (within 10 ppm of steady state value); current noise of 0.010 μVrms/V of applied voltage (< -40 dB); and a voltage coefficient of < 0.1ppm/V. The RoHS-compliant FRFC resistors offer a non-inductive (< 0.08 μH), non-capacitive design and are available in matched sets upon request.
Product Documentation
SMR1DZ/SMR3DZ Series -Ultra High Precision Z-Foil Molded Surface Mount Resistor
Ultra High Precision Z-Foil Molded Surface Mount Resistor Ultra High Precision Z-Foil Molded Surface Mount Resistor with TCR down to ±0.2ppm/°C, PCR of ±5 ppm at Rated Power, Flexible Terminations, and Load-Life Stability of ±0.005%(50 ppm)
Product Documentation
VSR Series
VPG Bulk Metal® Foil Technology Industrial Precision Resistors with TCR of ±4 ppm/°C and Tolerance of ±0.01 %
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.
Product Documentation
SMR1D/SMR3D High Precision VPG Bulk Metal® Foil Moulded Surface Mount Resistor
High Precision VPG Bulk Metal® Foil Molded Surface Mount Resistor with TCR down to ±2 ppm/°C, Flexible Terminations, and Load Life Stability of ±0.005 % (50 ppm)
The SMRxD is a precision moulded surface mountable resistor offering all the elements of precision; including low TCR, tight tolerance, long term stability, low noise, low thermal EMF, and non-measurable voltage coefficient.
Product Documentation
S Series - VPG High Precision Foil Resistor with TCR of ±2.0ppm/°C, Tolerance of ±0.005% and Load Life Stability of ±0.005%
The S series of BMF resistors offers low TCR, excellent load life stability, tight tolerance, fast response time, low current noise, low thermal EMF and low voltage coefficient, all in one resistor.
