is the power loss of mosfet equal current^2 * Ron?
so, how can i calculate the power loss on it?

 

Power = current^2 * Resistor
current^2=current * current=current squared
This is only the DC loss.

 

is the power loss of mosfet equal current^2 * Ron?

\( P = IV = I^2R = \frac{V^2}{R} \)

Since you don't know R, current time voltage would be more reliable.

 

Power = current^2 * Resistor
current^2=current * current=current squared
This is only the DC loss.

So, what is the other power loss?

 

\( P = IV = I^2R = \frac{V^2}{R} \)

Since you don't know R, current time voltage would be more reliable.

R is on datasheet right?
Power loss is due to resistance right?

 

R is on datasheet right?

The datasheet doesn't give you a way to determine ON resistance unless you're operating at the conditions they specified.

This is for IRF530:


If you're operating at Vgs=10V and Id=8.4A, the Rmax is 0.15 ohms. It could be less, but they don't say how much less. If you operate at different conditions, resistance will be different.

 

So, what is the other power loss?

Leakage and dynamic.