Hello all,
I frequently use this schematic to make the motor works:
scheme
My NPN's are IRF540n:
datasheet IRF540n
My PNP's are IRF9540
datasheet IRF9540
The problem is that the output pins of the UNO, that I use, generate 5V as OUTPUT, but i need to use for my next project a DUE (faster, with more pins and etc.), whos pins generate 3.3V as OUTPUTS.
So, with this parts and schematics, will the motors work at 3.3V?
Thanks 
Probably yes, but not guaranteed. The gate threshold voltage for these mosfets is between 2-4 volts. You will will be supplying most of that, but maybe just barely if the lot you have are on the higher end of this rating. You could look for some low threshold voltage mosfets where 1-2 volts is all that's required for turn on.
Lyle
i am actually in the same boat as you. I'm going to be driving some switec stepper motors (5v) but am switching over to an udoo board (due + linux)
i was wondering if this would work:
dual h-bridge motor controller: 5v
logic level shifter:
I'm just unsure if the logic level shifter will shift the logic level from 5v to 3v... or if it only does 3v to 5v.
A problem with that design is that the motor supply voltage needs to be the same as the Arduino output voltage, or only slightly higher (the difference needs to be less than the threshold voltage of the P-channel mosfets). It looks to me that you are probably running the motors from 6V. So with only 3.3V gate drive, as well as having the N-channel mosfets not turning fully on (unless you use N-channel mosfets with lower gaten voltage drive requirements), the P-channel mofets may not turn fully off.
How much current does the motor take? If it is 1A or less, then you could use this single-chip H-bridge instead: http://www.vishay.com/docs/70007/si9986.pdf.
Thanks to all for the replays
With the 5V as OUTPUT from the UNO i drive the motors with 7.4-8.4VDC from the bateries and it works fine. I have previously use L293D for motor driver, but they were overheating and turning off (the peak current of the motor is pretty high).
So I will try to find any low-threshold voltage mosfets (examples are wellcome 
)
I've read also here about logic level convertors, is there any on the market, that supports analog and digital signals, not only digital, becouse I want to use PWM?
Thanks
That bridge design is wrong in several ways, it has shoot-through, not enough gate drive,
no gate resistors.... And you need logic-level devices!
Anyway logic level converters convert logic signals so PWM is no problem, thats
a logic signal.
