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3 Phase Brushless (BLDC) Motor Driver Circuit

3 Phase Brushless (BLDC) Motor Driver Circuit

In this post we learn how to make a simple 3 phase brushless DC motor driver circuit. The circuit employs the popular IRS2330 3-phase driver IC

The presented idea looks simple since most of the technicalities is taken care of efficiently by the IC itself, it's all about connecting the relevant pinouts with the few external supplementary components for the required implementations.

How BLDC with Hall Sensors Work

We know that all BLDC motors fundamentally incorporate Hall sensors attached with their stator assembly where these devices play a crucial rule in detecting and supplying the control circuit with the necessary data regarding the rotor magnet instantaneous positions with regard to the stator coil activation.

The info helps the control circuit to subsequently changeover the stator electromagnet activations sequentially such that the rotor constantly experiences a rotational torque and produces the intended rotational motion.

Therefore it seems that the hall effect sensors are the ones that become solely responsible for detecting and inducing the intended rotational motion in BLDC motors.

The control circuit connected with the hall sensors are in fact "blind" and respond entirely to the hall sensor signals in order to produce the required feed backs to the electromagnet coils.

The above fact actually makes the designing of a 3 phase BLDC motor controller pretty easy, the simplicity also becomes further aided with the easy availability of the universal 3 phase H bridge driver IC such as the IRS2330.

Studying the IC IRS2330 Specifications

The following discussion provides a comprehensive view on the designing of a 3 phase brushless BLDC motor driver circuit:

Pinout Details of the IC

The above shows the pinout diagram of the IC IRS2330 which simply needs to be connected to a set of a few external components for implementing the proposed BLDC controller circuit.

How to Configure the Full Bridge IC

In the above diagram we witness the method of connecting the IC pinouts with some external components wherein the right hand side IGBT stage shows a standard H bridge configuration using 6 IGBTs integrated with the appropriate pinouts of the IC.

The above integration concludes the output power stage for the BLDC controller circuit, the "load" indicates the BLDC 3 phase electromagnet coils, now its all about configuring the inputs HIN1/2/3 and LIN1/2/3 of the IC with the relevant hall sensor outputs.

NOT gates for Sequencing the HIN, LIN Inputs

Before applying the hall sensor triggers to the driver IC inputs, it's required to be buffered through a couple of NOT gates as given in the diagram above.

Finally, the outputs of the NOT gates is integrated appropriately with the inputs of the IC IRS2330.

The negatives of all the hall sensors may be assumed to be grounded.

The second circuit which forms the main driver configuration for the proposed 3 phase brushless BLDC motor driver circuit, could be also seen having a current sensing stage across its lower left section. The resistive divider may be appropriately dimensioned for enabling an over current protection and control over the connected BLDC motor.

For getting comprehensive details regarding the current sensing configuration and other intricacies of the whole design, one may refer to the following datasheet of the IC:



About the Author

I am an electronic engineer (dipIETE ), hobbyist, inventor, schematic/PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials. If you have any circuit related query, you may interact through comments, I'll be most happy to help!

41 thoughts on “3 Phase Brushless (BLDC) Motor Driver Circuit”

  1. I bought a BLDC controller with forward reverse and speed control. Pot for speed control appears to be dual gang but only 3 terminals. 3K between red and black regardless of wiper position. Resistance between white and either red or black varies but is same. Gets up to 20K near midpoint then backs down. Seen this kind of pot before

    • No I haven’t yet seen pots with such a response, the resistance should increase or decrease proportionately depending upon the rotational direction until the end point reaches, it is not supposed to change the course in the midway.

    • yes, but this may happen, if the two end terminals of the pot are shorted, and the the response is measured across this common shorted terminal and the center terminal….

      • If the two pots are paralleled internally but wired opposite you would get Max at midpoint and less toward either end. But motor speed continues to increase as pot is rotated. Thanks

  2. I'm using 2130 ic with same pinout as 2330. Finished testing and ready to hook up to motor. Not sure how to control forward and reverse. Any thoughts?

  3. I'm waiting on 4049 in dip configuration. I should have been more careful to pick a config that meshes with my project boards .100 through board holes. Could use Arduino digital inputs but like your idea better. No programming!

    • thanks, by the way did you check the other BLDC drivers published in this blog? those surely seem to be more compact and advanced than the above concept

  4. The hall sensors on my BLDC work like a switch. They furnish a common (closed) signal or an open. If I connect vdd (+12vdc) to 12v led then to sensor lead it lights up as motor turns

  5. Thank you. i am working on building my own electric motor bike using 1KW BLDC motor from scratch. And i am looking for simple speed controller designs, do u have any suggestion for me to start with?
    Thank you

  6. Hi Swagatham,

    Liked the circuit, got the whole circuit set up.
    But not sure what to give as input to Hall1, Hall2, Hall3.
    Guess there should be a logic circuit, please help me with that.


  7. Hey Mr. Majumdar,

    Do you have any guides regarding a brushless sensorless motor control circuit? Am looking for any guides to help me out. Also I am willing to pay for some circuit designs if you are able and willing to help.


    • it's only a BLDC driver, it does not include a speed control feature….the speed control can be achieved by adding a PWM to the low side mosfet gates via a 555 PWM circuit.

    • sorry I am not so well versed with BLDC motors, the three wires probably would need to be connected across the three outputs from the bridge as shown in the above diagram

  8. Sir, how can we use your simple inverter circuit to use for charging purpose too with simple modification like using relay only. So it charge the battery and provide some backup on power cut. We can make it manual to backup process on when power cut (to avoid some complex modification in circuit) I got mosfet invertor circuit (it using hcf4047be ic) of 100 w from junk and want to use same transformer to charge the battery and for convertor purpose. Using 9-0-9 transformer we can get 18v to charge the battery as well with using of some diode to step down the current to 14v
    For eg can you provide that modification on this

    Looking forward to hearing from you.
    Kind Regards

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