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Knowing More About Foil Resistors Basically, a resistor has only two terminals in addition to a single property. This property is the resistance between the two. A metal foil resistor, contrary to a precision-class metal film resistor or wire-wound resistor, is a very high precision resistor in which the key resistance element is a special metal foil of merely a few µm thick. Utilization of this metal foil as the resistance part gives exceptional functionality definitely not present in other resistor. Special production technology as well as rigid quality control of the allow makeup also makes it possible for the temperature coefficient to be minimized in an unparalleled low value. Foil resistors employ a metallic resistive foil which lies on a ceramic substrate. Its particular attribute is the fact that its resistive thermal coefficient is balanced by the tension gauge impact of different thermal increase of the foil and then the substrate. This makes it entirely possible for the optimal use of this effect that results in a thermal coefficient which can be as low as 0.1 ppm/°C. Coupled with achievable resistance tolerances of 0.001% this makes foil resistors the very best performance parts accessible, however they are expensive. An extraordinary alloy foil is the principal resistance component of a foil resistor which measures several micrometers thick. Foil resistors, ever since their intro in the 1960’s, have been the top in stability and accuracy among all the resistors. TCR or temperature coefficient of resistance is among the critical factors influencing the stability of resistors. As time goes by, the value of TCR of foil resistors has been further enhanced even though they were already incredibly low. Important features of foil resistors: -

Tolerances to ±0.03%

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Has temperature coefficient of resistance ±1 ppm/°C

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-1.0 rise time

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Negligible induction

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It can hold up against electrostatic discharges not less than to 30kV without having deterioration

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Huge resistance range between 10 Ω to 125 k Ω

Foil resistors alongside oxide thin film have noise which is in close proximity to their theoretical thermal noise but carbon or thick film resistor now have greater noise level. Low noise level on the other hand, can be obtained from metal or oxide thin film but of course, they are going to cost you even more.


Knowing More About Foil Resistors