IRFZ44N. MOSFET .drive from AT90PWM3

[Dinuwilson]

can i drive mosfet drictly from AT90pwm3 PWM output..

input voltage(supply voltage) - 12V

my recomended ouput is 10V

frequency 20khz..

gate resistence is 10ohm

gate voltage(from at90pwm3 )--5V

i am driving mosfet directly from controller with out any isolation....is it possible to get 10v output by using 5v gate voltage..

i am alredy checked with 97% duty cycle in 20khz frequency. my output voltage is in 2.3v... if i decrease duty cycle voltage is decreasing..

 

[erikl]

Did you activate the AT90 internal output pull-up resistor? If so, its resistance may even be too large to load the ≈1nF gate input capacitance of the IRFZ44 in due time. Try and add an external pull-up resistor (suggest: 470Ω) between +5V and the AT90 output pin.

 

[Dinuwilson]

thank's for your replay..i tried that circuit which you are specified. but i cant get maximum output in my mosfet. i got one equation which specifies mosfet output voltage equal to gate voltage-threshold voltage. i use one 5v to 12 v shifter and got output

 

[erikl]

i use one 5v to 12 v shifter

Not a bad decision!