Quick Resistor Question

[marfire]

I'm building a BLDC motor controller with a pair of smaller transistors feeding the P channel mosfet (per channel). The manual for the controller chip I'm using suggests placing a series gate resistor of 10 ohms between the smaller transistors and the power mosfet. The system voltage is 13 volts, and at 10 ohms this would be 16.9 watts, which means an expensive to-220 resistor with heat sink. However, is that much current actually going to be going through that resistor or can I use a lower wattage resistor since only enough power will be going through it to close the Mosfet?

 

[ronsimpson]

For 50nS you will have the17 watts. The rest of the cycle there will be 0 watts. The duty cycle is unknown to me but probably <1%. That might be 0.17 watts.

 

[marfire]

Thank you!