Which driver for this stepper motor?? Thanks

Hi Eduardo,

If I were to drive this motor, I would use either DRV8818 or DRV8825. My reasoning is you may want to go to as high as 2A and these are the two drivers that can easily get you there. DRV8818 will run cooler and has more tweaking knobs than DRV8825. DRV8825, on the other hand, requires quite less external components and configuration plus goes to as much as 32 degrees of microstepping. They can both offer 2.5A sine wave peak if properly soldered into a well designed two layer board.

You are definitely in the right track when deciding to use an integrated driver over discrete FETs. To not use an integrated solution nowadays is practically unheard of thanks to all the benefits we can pack on a single device, not to mention the considerably reduced price and layout real state requirements.

Just as a correction on some of the statements above, you will want to increase current to increase torque. Increasing the voltage allows you to charge the winding quicker which in turn allows you to step the motor faster, but it has nothing to do with torque. You can drive this motor at 45V and 100 mA and the torque will be very small, whereas if you use 12V and 2A, the motor will give you maximum torque. Granted you will be able to step faster at 45V than at 12V. Do note you will also get more switching losses (and heat dissipation) at 45V than at 12V, but you know the laws of physics. They let you win one battle at the expense of another.

Hope you have fun driving this motor! Best regards,

Jose Quinones

Hi Jose! thank you for the explanation, I'll check both.

With the same driver, is possible to use 45V and 100mA to move quickly the motors and then use 12V and 2A to move slower but stronger?

Thank you again!

Eduardo.-

pd: do you speak spanish? can I contact you in any messenger?

Hi Eduardo,

DRV8825 will go up to 45V, but DRV8818 goes only to 36V recommended. The DRV8818 Abs Max is 40V, but 36V is the most you should do as during current recirculation voltage goes up and down depending on voltage supply and loading current. You should take a look at both datasheets and study the devices in order to determine which one will be best for your own application. What are  you trying to design?

Hardly ever I see implementations in which you can change the input voltage. If you are willing to go this route, then by all means. However, in real life to apply two voltages is way easier said than done. Chances are you will want to stay with a voltage high enough to let you accomplish what you need to do. The voltage we see the most out there, with an appaling victory, is 24V. Some applications will do 12V, and a truly small number may use 32V or 36V. Then it jumps from there to 60V and even 80V on industrial applications. The 80V applications, however, will use specialized driver topology which is out of the realm of the integrated driver. For the most part, 24V is the way to go. It will give you decent speed and good torque.

I do not frequent a messenger channel, but I do speak spanish fluently. Feel free to write to my email address at jquinones@ti.com and I'll be happy to help you as much as possible.

Best regards,

Jose Quinones

Hi Jose, I want to make an small 3 axis cnc machine and use a dremel or another kind of small motor with more rpm as head.

I want to be able to make pcb but I don't know if I will be able to work with wood, acrylic or another material.

I have microcontrollers, the stepper motors, some switch sensors from old printers for end of travel.

Is there another IC that would help me with this project? beside the motor driver.

Thank you!

Regards,

Eduardo.-

Hi All,

Currently i'm using DRV8818 to drive a bipolar stepper motor. I'm using 2 phase stepper motor (DC24v, 2A), 1.8 degree, 200 step per revolution.

How this DRV8818 calculate the total maximum power dissipation since the heating problem is very important issue to me?

Thnak you.

Regards,

NorAin