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DRV8818EVM: BOUT polarity

Part Number: DRV8818EVM
Other Parts Discussed in Thread: DRV8818

Hello Team,

I am working with a customer who believes there is a datasheet error in the functional diagram on page 9 with respect to BOUT1 and BOUT2. 

On the data sheet, DRV8818 ( revised January 2016), functional block diagram present description :
AOUT1 --> COIL1
AOUT2 --> - COIL1
BOUT1 --> COIL2
BOUT2 --> - COIL2

To make sure, your driver is working properly ( as also indicated on the DRV8818 EVM for connector J2), the connection is .
AOUT1 --> COIL1
AOUT2 --> - COIL1
BOUT2 --> COIL2
BOUT1 --> - COIL2


Could you please confirm this point ?

Attached is a detailed documentation of what they are asking.

I would appreciate you suggestions on this.

Thank you for your time.

Kishen

DRV8818_connection V1.pdf

  • Hi Kishen,
    I would look into this and send a reply as soon as possible.
  • Hi Kishen,

    I am not sure I understand what the question is.

    Is the question:
    1) Are the pins BOUT1 and BOUT2 be correctly labeled in the functional block diagram?
    Answer: Yes, this is correct. When the device is at the home state, the current path is from BOUT1 to BOUT2 (71% of full scale)

    2) Does connector J2 match the motor the customer is using?
    Answer: No, the layout was done to minimize routing. There are two ways to correct this for evaluation.
    When connecting the motor to J2, the motor will spin in the opposite direction. The direction pin set to achieve the desired direction.
    Connections can be rewired to the screw terminals to match the motor connections.

    3) Other question?
  • Thank you Rick, Luis for your support with this. Up till now, the customer is sure that the board was designed with the connections

    AOUT1  blue        B

    AOUT2  orange    B\

    BOUT2   red           A

    BOUT1   yellow      A\

    with the stepper motor MINEBEA 23KM,  it functions perfectly.

    So  the customer is confused with the fact that , normally this solution  should not work

    You will find  the document  version V2 (page1)    for more details

    Again thank you for your assistance with this.

    Sincerely,

    Kishen

    DRV8818_connection V2.pdf

  • Hi Kishen,

    One of the interesting notes about steppers is that the motor works as long as the two terminals of winding are connected to the same full bridge. The motor direction may be opposite the expected direction.