To further illustrate this concept, take a simple RLC model consisting of ESL, ESR, and capacitance. As AC current flows through the MLCC, power will be dissipated through the ESR as denoted by the letter P. The temperature rise of the MLCC is calculated by multiplying the dissipated power by the thermal resistance of the MLCC which can be found in KEMET’s KSIM tool. Consider an example of an MLCC with an ESR of 40 mΩ and a thermal resistance of 32°C/W operating at 5A_RMS. The dissipated power of the MLCC is calculated by multiplying the current squared by the ESR. In this case, the dissipated power is 1.01W. To get the temperature rise of the MLCC, multiply the dissipated power by the thermal resistance which is 32°C. The table above shows the three temperature zones which define the risk of operating the MLCC above its ambient temperature. The first zone is where the maximum allowable temperature rise is below 20°C above ambient. Operating in this zone is considered safe for all applications. The second zone is where the maximum allowable temperature rise is between 20°C and 50°C above ambient. Operating in this regions is considered medium risk and is dependent on the application. The third zone is where the maximum allowable temperature rise is above 50°C above ambient. This is considered a high-risk zone and KEMET does not recommend operating in this region. In addition to maximum allowable temperature rise, the maximum temperature of the MLCC must never exceed the rated temperature as specified in the datasheet.