If TJ and TA are junction temp. and ambient temp respectively θJC, θCS and θSA are transistor thermal resistance, insulator thermal resistance and heat-sink thermal resistance respectively. The equation of maximum power dissipation is given by

• A. \(P_D=\frac{T_J+T_A}{\theta_{JC} + \theta_{CS}+\theta_{SA}}\)
• B. \(P_D=\frac{T_J-T_A}{\theta_{JC} + \theta_{CS}+\theta_{SA}}\)
• C. \(P_D=\frac{T_A-T_J}{\theta_{JC} + \theta_{CS}+\theta_{SA}}\)
• D. \(P_D=\frac{T_J-T_A}{\theta_{JC} + \theta_{CS}-\theta_{SA}}\)