Is the on-state resistance of a MOSFET dependent on temperature?

MOSFET on-resistances generally have thermal dependencies. Its temperature coefficient is positive. In other words, the resistance value increases at high temperatures and decreases at low temperatures.

Fig. 1: Example of temperature characteristics of on-resistance
Fig. 1: Example of temperature characteristics of on-resistance

Generally, the temperature coefficient of the resistance value of a metal conductor is positive, and the temperature coefficient of the resistance value of a semiconductor is negative. However, the temperature-coefficient of the on-resistance of MOSFET is positive. The value of the coefficient varies depending on the breakdown voltage and manufacturing process of the device, so it is necessary to check it by seeing a data sheet, etc. When designing, take this temperature fluctuation into consideration, and carry out thermal design and circuit design.

Please also refer to FAQ below for the variation of resistors.

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