Max power supply voltage for EasyDriver v4.4 with Arduino UNO R3


I have a question about the supply voltage when using easydriver v4.4.

I am making a small CNC by using 3 bipolar stepper motors out of old printers. I will control the motors with easydrivers v4.4 that will be attached to arduino uno and for software I will use GRBL Shield.

So for stepper motors it is prefered to have high supply voltage for motors, higher the voltage higher the torque which comes very handy when making a CNC. The voltage should be around 3-25x higher from the voltage of motor, for example if the motor requires a min. of 2V, you need to supply atleast 6-60V to really make the most of the motors torque.

Now the thing is that I am planning to buy a power supply unit and I don't know if I should buy a 24V or a 36V one. 36V would be better but easydriver v4.4 allows supply voltage from 7-30V. Will I harm it in any way if the supply voltage is a little higher or has the easydriver a built in safety system and therefor it only takes the allowed amount of it? Because I would like to buy a supply that I could also use it for other projects by using other softwares and stronger motors that require higher supply voltage (for example NEMA 17, NEMA 23,...).

Thanks in advance,



at TA = +25°C
Load Supply Voltage, VBB ............. 30 V

Here's what you can do, ditch the Easydrivers and get A4988-based drivers.
The A4988 can handle 36V, although I would recommend not using the max. voltage. Put a few diodes in with a 36V supply.

Or, the TI DRV8825 Driver

Its not just the chip that has to be rated high enough - the decoupling capacitors on
the PCB need to be rated high enough too, so read datasheet for the motor driver
module, not just the chip.

Be aware that as you get closer to the max voltage the more important it is to avoid
spikes on the supply rail which could cause over-voltage failure. Good decoupling is
needed and TVS diodes are worth having too to clip any wayward spikes.

What current motors are you thinking of? No single chip drivers comfortably handle
more than about 1.3A (though adding heatsinks and fans will help). Industrial stepper
drive units are available for the higher currents, and these usually support much higher
voltages too.