A MOSFET has the following datasheet: http://www.vishay.com/docs/91015/sihf510.pdf
which states for the max. ratings:
Maximum Power Dissipation = 43W
Continuous Drain Current = 4A (at 100°C)
RDS(on) = 0.54 ohm
What I interpret from this info is: In continuous operation this MOSFET should not exceed 4A. And since RDS(on) = 0.54 ohm, the power at max allowable current:
P = Imax^2*R so P = 8.64W (I think this is the max power of MOSFET can handle without any heatsink?)
So if I obey the datasheet I find 8.64W but the datasheet says the Maximum Power Dissipation is 43W.
Does that mean the maximum power dissipated by a big heatsink cannot be more than 43-8.64 = 34.36W ?
And secondly datasheets says:
"The TO-220AB package is universally preferred for all commercial-industrial applications at power dissipation levels to approximately 50 W" Is 43W approximately 50W? What is this 50W?