| HOT SPOT CALCULATION 9hot spot = Qcase + (Pd + Pt) X Rth with Pd (Dielectric losses) = Q x tg8o = [ 1/2 X Cn X (Vpeak to peak)2 X f ] X tgSo (see tg80 vs dielectric pages 2 and 3) Pt (Thermal losses) = Rs X (Irms)2 where Cn in Farad Irms in Ampere f in Hertz V in Volt Rs in Ohm 9 in °C Rth in °C/W Rth hot spot/bottom case 9case = bottom middle case |