High-Precision Current Sense Resistor with Low TCR
VPG Foil Resistors, a Vishay Precision Group, Inc. product group, announced today 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 degrees C for 2,000 hours with a low TCR of ±5 ppm/ degrees C max from -55 to +125 degrees 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 50mΩ to 200mΩ 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 25kV 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 10 W for 5 seconds on the device were passed with a maximum R 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."
Samples and production quantities of the new CSM3637F resistors, either RoHS-compliant (lead (Pb)-free) or with tin/lead alloy terminations, are available now with lead times of five to eight weeks. The CSM3637F resistors will be among the products on display during electronica 2016 at the VPG Foil Resistors booth B6/116 at the Messe München, Nov. 8-11.
