Wrap-Around Chip Resistors offer resistance down to 5 ohm.
July 17, 2012 -
Bulk Metal® Z-Foil wrap-around chip resistors of VSMP series offer respective TCRs of ±0.05 and ±0.2 ppm/°C typ from 0 to +60°C and -55 to +125°C, with +25°C ref, and load-life stability ratings of ±0.005% for 2,000 hr and ±0.01% for 10,000 hr. Offered in 7 chip sizes from 0603-2512, non-inductive products have power ratings to 750 mW at 70°C and power coefficient of ±5 ppm. Resistance range, depending on case size, varies from 5 ohm to 125 kohm, with tight resistance tolerance to ±0.01%.
|Original Press release |
Vishay Precision Group
3 Great Valley Parkway, Suite 150
Malvern, PA, 19355
VPG Extends VSMP Z-Foil Ultra-High-Precision Wrap-Around Chip Resistors Down to 5 ohm with ±0.005% Load-Life Stability
MALVERN, Pa. - Vishay Precision Group, Inc. (NYSE: VPG) today announced that its Vishay Foil Resistors (VFR) brand has enhanced its VSMP series of Bulk Metal® Z-Foil ultra-high-precision wrap-around chip resistors with an extended resistance range down to 5 W for sizes 0805 and larger. The devices feature ultra-low TCR of ±0.05 ppm/°C typical (0°C to +60°C) and ±0.2 ppm/°C typical (-55°C to +125°C, +25°C ref.), and load-life stability of ±0.005% at 70°C for 2,000 hours at rated power and ±0.01% at 70°C for 10,000 hours. For designers, the resistors are available within a few days from one of VPG's Precision Centers or catalog houses around the world.
Available in seven chip sizes from 0603 to 2512, the VSMP series offers high power ratings up to 750 mW at +70°C and an excellent power coefficient of ±5 ppm at rated power. The devices feature a wide resistance range from 5 W to 125 kW, with tight resistance tolerance to ±0.01%. Any resistance value within this range is available at any tolerance with no additional cost or lead time effect. Matched resistor sets are available by request.
The extremely low TCR of VSMP resistors over a wide temperature range makes them suitable for the high demands of cryogenic applications. In addition, the devices are ideal for use in many alternative energy and smart grid applications, where analog circuitry operates under severe environmental, thermal, and mechanical conditions. Designing and manufacturing equipment for this environment involves extreme challenges that seemed insurmountable until a few years ago. These challenges have an impact on the design of analog circuits in alternative energy applications, and on the role and expectations of precision resistors, which must be ultra-stable, ultra-reliable devices with an extremely low total error budget.
Many designers use a resistor's TCR as a shorthand index to the resistor's relative level of precision. While it is generally true that a better TCR does correspond to higher precision, this degree of precision does not maintain the same TCR/precision proportion across all technologies. For Bulk Metal Foil resistors, the stress/strain balance throughout the temperature and power application ranges ensures that none exceeds the elastic limit (Hooke's law) for any material used and that all performance criteria are repeatable and reliable.
"In recent months, all sorts of precision electronic components have been targeted by counterfeiters who dump very realistic looking but unreliable copies of precision electronics onto the market," said Yuval Hernik, senior director of applications engineering for Vishay Foil Resistors. "This is causing confusion about the differences between actual and published specifications, and it contaminates storehouses and circuits with unreliable and under-performing parts. It is said that imitation is the sincerest form of flattery. However, counterfeiting is a crime, and the consequences of substituting fake Bulk Metal Foil resistors for real ones in analog circuits, systems, and programs can be very grave indeed. That's why it is more important than ever to verify that the foil resistors you're using are in fact the high-precision devices you believe them to be. The best way to counter these fraudulent scams is to buy only from VFR or its authorized distributors and catalog houses."
Many users of precision electronic equipment suffer needlessly from unexplained instabilities and drifts due to noise effects. They resign themselves to making constant adjustments and troubleshooting, but, in fact, these can be avoided. Bulk Metal Foil VSMP resistors owe their low excess noise and high linearity to the type of material of which they are made: a cold-rolled metal alloy foil with a thickness of several microns.
Featuring a non-inductive (<0.08 µH), non-capacitive design, VSMP devices offer a rise time of 1.0 ns with effectively no ringing, a thermal stabilization time of <1 s (nominal value achieved within 10 ppm of steady-state value), current noise of 0.010 µVrms per volt of applied voltage (<-40 dB), and voltage coefficient of <0.1 ppm/V. VSMP series resistors are immune to extraordinary incidents such as radiation exposure and withstand ESD spikes to at least 25 kV.
The VSMP resistors' full wrap-around terminations ensure secure contact during the manufacturing process and also provide stability during multiple thermal cyclings. The devices are available with both lead (Pb)-free and tin/lead alloy terminal finishes.
Samples and production quantities of the Z-Foil resistors are available now, with lead times of five days for prototype samples and two days to five weeks for standard orders at the catalog houses (depending on their shelf availability). Pricing for the improved VSMP devices starts at $4.08.
Further information about Vishay Foil Resistors products is available at www.vishayfoilresistors.com. Follow Vishay Foil Resistors at http://twitter.com/foilresistor.
About VPG Foil Resistors
Distinguished by the premier brands Vishay Foil Resistors, Powertron, and Alpha Electronics, VPG Foil Resistors is part of Vishay Precision Group (VPG), producing the most precise and stable resistors available. The portfolio comprises products in a variety of resistor and package configurations to meet the needs of a wide range of applications: discrete resistors and resistor networks in surface mount and through-hole (fixed-lead) configurations; customized chip resistor networks; precision trimming potentiometers; and discrete chips for use in hybrid circuits. The foil resistors and current sensors are used in applications requiring a high degree of precision and stability, such as in medical testing equipment, semiconductor equipment, precision measuring instruments, aerospace, and military applications.
About Vishay Precision Group
Vishay Precision Group (VPG) is an internationally recognized designer, manufacturer and marketer of: components based on its resistive foil technology; sensors; and sensor-based systems specializing in the growing markets of stress, force, weight, pressure, and current measurements. VPG is a market leader of Foil Technology Products, providing ongoing technology innovations in precision foil resistors and foil strain gages, which are the foundation of the Company's Force Sensors Products and its Weighing and Control Systems. The product portfolio consists of a variety of well-established brand names recognized for precision and quality in the marketplace. To learn more, visit VPG at www.vishaypg.com.