Resistor Composition Differences

Resistor composition can determine whether you are able to choose the specifications necessary for your application or not. Often, the lower the cost, the less specific a resistor can be.

For through hole options, Digi-Key sells carbon composition, carbon film, ceramic, metal element, metal film, metal foil, metal oxide film, thick film, thin film, and wirewound resistors. For surface mount options, Digi-Key sells carbon composition, carbon film, metal element, metal film, metal foil, thick film, thin film and wirewound. As this post will cover the basics of the resistors, I won’t be differentiating between surface mount and through hole, as they are very similar at the basic level.

Carbon resistors are typically larger in size, have lower power offerings, loose tolerances, have large temperature coefficients, and can have noise at higher temperatures. On the upside, they are cheaper than most, and typically work well for higher frequencies.

Ceramic resistors have higher temperature coefficients, medium operating temperature ranges, and are typically more expensive than most.

Metal Element resistors are often used in current sensing applications. They are very precise, offered in low resistance values and low tolerances.

Metal Film resistors have good temperature stability, low noise, and wide resistance values with tight tolerances.

Metal Oxide resistors are very similar to metal film, but they can withstand a surge more effectively and come in higher temperature ratings.

Thick Film resistors have noise and a low surge tolerance but have a good temperature stability and high voltage ratings. They are offered in a large variety of resistance values.

Thin Film resistors have low noise, high lifetime stability, low temperature coefficients and high resistance values.

Wirewound resistors work well for high power, high current applications. On the flip side, they high noise and have lower resistor values. Non-inductive options are available as well.

Overall, if you are looking for best variety in resistance values, thick or thin film will be your best option. Shopping by price, I’d look at carbon film, metal film, or thin film. If a tight tolerance is needed, stay away from carbon and ceramic. For high wattage applications, I’d look at thick and thin film. For high or low temperature applications take a look at thin film or wirewound.