
Temperature Effects in Resistors
The value of a resistor changes with temperature. The relationship between
resistance and temperature is defined as the temperature coefficient (TC) and is
specified in parts per million per degree centigrade (ppm/
C). Typical tempera-
ture coefficients for film resistors range from 25 ppm/
C to 100 ppm/
C. The
formula for calculating the temperature coefficient is as follows:
TC ¼
R2 R1
ðT2 T1ÞR1
10
6
where TC ¼ temperature coefficient, T2 ¼ temperature 2, T1 ¼ temperature 1,
R2 ¼ resistance at temperature 2, and R1 ¼ resistance at temperature 1. To find
the new resistance at a new temperature, we can rearrange the ...