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Electronics => Projects, Designs, and Technical Stuff => Topic started by: auto_mitch on March 30, 2013, 05:07:22 pm

Title: Driving a single mosfet
Post by: auto_mitch on March 30, 2013, 05:07:22 pm

Hi!
I am trying to build a high power speed controller for a DC motor.
I want to control the motor only to one direction. I decide to use a single mosfet with a mosfet driver as the following schematic shows.
Mosfet: http://www.irf.com/product-info/datasheets/data/auirl1404z.pdf (http://www.irf.com/product-info/datasheets/data/auirl1404z.pdf)
Driver: http://ww1.microchip.com/downloads/en/devicedoc/21422d.pdf (http://ww1.microchip.com/downloads/en/devicedoc/21422d.pdf)
D1: http://www.sirectifier.com/datasheet/High%20Tjm%20LOW%20IRRM%20Schottky%20Barrier%20Diodes/MBR3050CT%20thru%203060CT.pdf (http://www.sirectifier.com/datasheet/High%20Tjm%20LOW%20IRRM%20Schottky%20Barrier%20Diodes/MBR3050CT%20thru%203060CT.pdf)
The frequency of the pwm is 23,53Khz. The problem that i face is that the mosfet is getting very hot when i try to change the duty cycle of the pwm. I have tried lower freq like 5Khz but the mosfet is getting hot again.
I dont know if there is something wrong with my driver. Any ideas?

Title: Re: Driving a single mosfet
Post by: NiHaoMike on March 30, 2013, 05:10:09 pm

You need another fast recovery diode across the load.