Power MOSFET equalizer resistors

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fjpompeo

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Hi all,

Need to know if is there need to use equalizer resistors (0R1-5W or less) when paralleling N-channel Power MOSFET transistors like IRF46N?

Regards,

Fernando
 

No, the ON resistance of MOSFETs has a positive temperature coefficient, so parallel MOSFETs are not susceptible to current hogging and subsequent thermal runaway. As one starts to get hot, its resistance goes up and forces other devices to take more of the load.
 

10kangstroms,

Very thank you for your explanations, so you said when the transistors get hot the on resistance increases but doing this there will be a difference between the current on each one. How do I equalize this current split in order to get almost the same curent flowing thru each one to be as close as possible?

BTW This configuration will be used as power transisors in a 13,8V @ 30A negative rail regulated linear PSU!

Regards,

Fernando - Call sign PU2PLL
 

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