SMD resistors offer high stability at lower performance levels

March 09, 2015 // By Paul Buckley
Isabellenhütte has closed a gap in the company's resistor range with the introduction of resistors that address medium and lower performance requirements in the SMD-mountable precision and power resistor segment.

The existing SMx and VMx SMD series include resistors for high-end applications but the new CMx series meets the market demand for reduced technical performance and is available in the standard sizes 2512, 2010 and 1206. The CMx resistors work in the temperature range from -65 to 170°C, making them suitable for both industrial applications and as components in vehicle applications. In the automotive sector, they comply with the AEC-Q200 specifications and fulfil the criteria of RoHS 2011/65/EU.

Despite their reduced resistance, the CMx resistors offer the same quality features as other Isabellenhütte resistors, such as high long-term stability, optimum temperature coefficients and high load capacity. The TCR of the entire range is below 75 ppm/K.

The TCR of resistors made by other manufacturers varies across the value range and nominal load depends on the ambient temperature. However, contact point temperature is the key point of reference for applications. Together with the load and stability of the component, it is decisive. Users also benefit from the long-term stability of Isabellenhütte’s technology. Long-term stability after 2,000 hours of operation is excellent, with deviation of less than 1.0 per cent from the original values for all sizes.

All three versions have a high load capacity. The CMS has resistance of 10 to 500 mOhm at a nominal capacity of 2 watts. The CMP also has resistance of 10 to 500 mOhm with load capacity of 1 watt. The CMK offers resistance of 10 to 100 mOhm and a load capacity of 0.5 watts.