In this article, we are going to explain MOSFET power dissipation, which is an important topic when we opt for a component for a circuit.

In this post, we explain to you about the MOSFET power dissipation factor which is responsible for the dissipation, the calculation methods, and also the formula for power dissipation at MOSFET.

MOSFET power dissipation calculations

The power dissipation is defined as the maximum power dissipated continuously at the MOSFET, which is under specific thermal conditions.

In general, it is defined between channels, case when mounting an infinite heat sink.

 At the MOSFET, the power dissipation is been calculated with help of so many factors.

                      Power dissipation (P_D) = P_{D resistive} + P_{D switching}

The power dissipation at the MOSFET are been calculate by the sum of resistive power dissipation + switching power dissipation.

The resistive power dissipation actually depends on many factors such as,

• Channel to case thermal resistance(internal thermal resistance)
• Insulator thermal resistance
• Contact thermal resistance
• Heat sink thermal resistance

MOSFET power dissipation formula

Power dissipation (P_D) = P_{D resistive} + P_{D switching}

                                      P_{D resistive} = (I_LOAD² _* R_{DS (ON)}) _* (V_out / V_IN)

                                      P_{D switching} = (C_{RSS *} V_IN² _* F_{sw *} I_LOAD) / I_GATE

 

                                      P_D = I_OUT 2 * R_ON + V_IN * I_Q

P_D = Power dissipation

I_OUT= output current (A)

R _(ON) = on resistance (Ω)

VIN = Input voltage (V)

I_Q = Quiescent current (ON state) (A)