Parallel operating stepper motor Driver IC for compact package

Hi people,

I am working on a project that has high space constraints. My system uses four 28BYJ-48 Stepper motors and each motor is controlled by the ULN2003 Motor Driver IC. I am relatively new to this IC and all my knowledge on how these IC works come from https://components101.com/stepper-mo...nout-datasheet

But I have some confusion here, as per the link the IC has 7 Darlington transistors and each can source up to 500mA. So does this mean when I use 4 pins to drive my stepper motor I can load the IC to 2A maximum?

My motors consume only 700mA even at full load, and not more than two motors will rotate at the same time. The motors that rotate at the same time will have the same steps. So my question is can I use a single driver ic to drive control two motors at the same time?

Hi,
ideally you would have a bridge which would be four switching tranisors/MOSFETs/IGBTs per stepper.

Those ULN2003 ICs are just DIP cases with no heatsink.....I suspect you'll cook them long before you get to 2A

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The motors that rotate at the same time will have the same steps. So my question is can I use a single driver ic to drive control two motors at the same time?

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That is possible, not particularly practical, just possible.

If space is that tight use SMD MOSFETS, less board real-estate and vastly more current capable.

Craig

If you have more than one output active at the same time, you must derate the current. According to ULN2003 datasheet (SOIC package, which is what you want to use I presume), if you have 4 active outputs with 50% duty cycle, the maximum current per transistor is only 200mA.

ULN2003 is not really a "motor driver" anywhere outside Arduino world. I would look into something like MOSFET arrays or even discrete MOSFETs instead.

Now, if you want to try something interesting, there is Texas Instruments DRV8860. It's an 8-output driver with a shift register and serial input, so you can save a lot of I/O pins.