My requirements require using 16C711 that doesn't have PWM hardware. Can I effectively use the PWM command to control a logic level MOSFET directly without incorporating RC to condition signal output?

When driving high loads of say 25A, how would you deal with the heat of say 30W [(25)^2 * 0.05] off a TO 220 MOSFET? Seems heat sinks are limited to 5W?