Using PCA9685 to drive MOSFET IRFZ44N

[Velth]

Hello I want to know if it'll be any problem with de follow schematic that I made
I want to use this system to control a DC motor
The signal PWM_OUT1 will come from  PCA9685 in 5V
I want to drive 12 Motors like this, but I'm afraid of the current drained of PCA it will be enough.

[DavidAlfa]

That FET is pretty old, less sensitive to gate voltage, I would use a newer one, Rds on will be much better @ 5V.

[Benta]

If you want to PWM the motor, the 10 uF cap will defeat that purpose completely. Why is it there?

[Velth]

I want to use in 100hz,  I thought to put a cap there maybe 0.1uf just to clean the signal 
What other FET would you recomend to me ?

[Benta]

I thought to put a cap there maybe 0.1uf just to clean the signal 

Extremely goofy idea.
Look for a logic-level MOSFET, 5 V insn't really enough for driving the IRFZ44.

[T3sl4co1l]

At what frequency?

IRFZ44N at 5V is hopeless, but there is a logic-level IRLZ44N that would do.

With those values, running above 10kHz or so is unlikely to be fruitful.  I guess from the diode, it's not much current anyway, and maybe a '3055 would do for example.  Like uh, RFD3055LESM9A let's say.

Remember to place the FET, diode and a bypass capacitor (100uF+ electrolytic would be enough here?) very close together.  It's the transistor that causes the motor to flyback, not the motor doing it by itself: don't put the diode at the motor.  So the clamp diode also goes at the transistor.

Tim

[PCB.Wiz]

I want to use in 100hz,  I thought to put a cap there maybe 0.1uf just to clean the signal 

The SCH says 10uF and you say 0.1uf, both are too large for PWM.
A modest cap is not a bad idea to slow down the FET edges a little, but keep in mind slower edges mean more heat loss.
You can get a similar effect with the inherent FET capacitance and a higher gate drive R.

You could try something like 470~1k  ohms series R.

What other FET would you recomend to me ?

What package and what current ?
There are shiploads of Logic level MOSFETS out there, search by package and voltage and RDS at 4.5Vgs


eg Digikey has
GT088N06T TO-220  N-Channel 60 V < 13 mΩ at 4.5 Vgs
MCP90N06Y-BP N-Channel 60 V  TO-220AB  < 10 mΩ at 4.5V Vgs

or, you may like insulated TAB TO220

TK4R3A06PL,S4X MOSFET N-CH 60V TO220SIS < 7.2 mΩ at 4.5V Vgs

[Velth]

I thought that 5V would be more than necessary , that I need to change de 100 resistor to lower this voltage
My load is a 12/24V motor that can consume  almost 2A  with 100hz pwm
The bypass capacitor that TIM said 100uf  but I presume that I need i lower capacitor,   gonna put it on gate right ? 
The package to me is irrelevant I want something cheap and that won't disappear in a few months or years.

[PCB.Wiz]

I thought that 5V would be more than necessary , that I need to change de 100 resistor to lower this voltage
The bypass capacitor that TIM said 100uf  but I presume that I need i lower capacitor,   gonna put it on gate right ? 

I would omit gate C entirely, initially, and increase the 10k to 100k, it is only there to keep the gate OFF with no drive.
The 100R can increase to 470~1k fine for 100Hz PWM.

My load is a 12/24V motor that can consume  almost 2A  with 100hz pwm

You may need to check the inrush current,

The package to me is irrelevant I want something cheap and that won't disappear in a few months or years.

Most designs have some dictates around package, as that is determined by how you want to mount it.  Are you doing a PCB design for this ? Will you get it assembled ?

Common packages are TO-220, TO-220F, TO-263/D2PAK (the SMD version of TO-220) and DPAK, the smaller SMD brother.

Also common in SMD are SO-8 and compatible footprints.
If you are doing 12 channels, and making volume production, PCB size and time matter, so you might look at Dual Mosfets in SO-8 and compatible flat-pack variants.

eg Diodes inc have DMTH6016LSD variants, in stock at Digikey and Mouser  SO-8  < 24mOhm at 4.5Vgs, 60V Dual

[SiliconWizard]

I want to use in 100hz,  I thought to put a cap there maybe 0.1uf just to clean the signal 

Except that even if the PWM frequency is very low, you still want as short edges as possible to avoid keeping the MOSFET in its linear region for too long.
Otherwise it's going to have huge losses and dissipate all that as heat.

[T3sl4co1l]

No capacitor on the gate.  The capacitor goes between +24V and GND.

Tim