How MDO3A works?

i’m about to finish my programing to control 2 dc motors 5A each. but need confirmation from polulu about a few thing keep buging me. do i need to electrically STOP(by shorting terminal) my motor every time i need to change direction…or will this driver take care of it? and can i use 14v psu to power my motor? i’m not sure if my psu can handle regenarative power and blown polulu driver.


The motor drivers do not do any extra braking on their own. In general, especially with bigger motors and mechanisms, I would recommending not making really abrupt direction changes, especially if you are using bigger motors, but it’s all up to you and your system. If you use our more advanced motor controllers, they have things like braking and acceleration built in.

I don’t know how you expect anyone to respond to your last question and statement pair. It’s good for you to wonder about it, but you have provided no information about it other than the 14V part, which should be fine.

- Jan

the excessive power coming from motor when we stop them…so this will generate reverse power to driver. some driver pass it back to battery(charging like hybrid car) some driver only change it as heat. that what i mean by " regenerative" power. so how polulu driver handle this?

First off, our company name is Pololu. The item you are asking about is a simple carrier with schematic provided for a component that has a datasheet detailing its operation. You should see that there is nothing we are doing to “handle this”. This is just a driver, and a lot of the ultimate performance depends on what you do with it. Usually, doing some kind of meaningful regenerative braking requires extra effort. If you just turn off the legs of the H-bridge (we usually call it “coast”), the motor will slow down because of mechanical reasons, and no extra voltage will be shown to your power supply. However, there would be no electrical braking, and if you spin the motor faster than it does off of your 14 V supply, the motor will generate a higher voltage that would be presented to your supply. If you just do a full brake by effectively shorting out your motor, you would just put everything into heat and not supply anything to your power supply.

- Jan

than q so much. i think i get it :smiley:

at the moment I wish to migrate my 2DOF project to pic32 core mcu for realtime graphical analyzer and more interrupt option. but pic32 only use 3.3v TTL PWM output for their new system architecture. what is the minimum voltage to fully switch this pololu motor driver?

Your “fully switch” phrasing makes me think you don’t quite understand the digital aspect of the interface, so you should make sure you do. The minimum high voltage is listed as 3.25V, so you’ll technically be right at the limit, but you’ll probably be fine for just playing around with it.

- Jan

I do read datasheet before but just to make sure from pololu expert. As you may know some mosfet has its own behavior on switching level. :smiley: