The 303133 through to 303138 series is the first surface mount device to provide high rated power, excellent load-life stability along with extremely low TCR all in one resistor. One of the most important parameters influencing stability is the temperature coefficient of resistance (TCR). Although the TCR of foil resistors is considered extremely low, this characteristic has been further refined over the years.
The 303133 through to 303138 series utilizes ultra high-precision Bulk Metal® Z-Foil. The Z-Foil technology provides a significant reduction of the resistive element’s sensitivity to ambient temperature variations (TCR) and to self-heating when power is applied (power coefficient). Along with the inherently low PCR and TCR, Z-Foil technology also provides remarkably improved load-life stability, low noise and availability of tight tolerance.