• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 30 subscribers
  • Views 306 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DRV8908-Q1: Parallel mode

Ryan Wang
Expert 7495 points
Part Number: DRV8908-Q1

Dear expert,

Can DRV8908 support Parallel mode like below? Two/Three/Four H bridge in parallel to drive  ONE H bridge for 2/3/4A output current? 

How to guarantee internal FET can ON/OFF at exactly the same time? Is there any risk if there is some minor time difference between different FET switch?

How to detect fault, like OVP, OCP, over temperature in this Parallel mode ?

Is there any mature mass production project with this mode?

Thanks

  • 0
    TI__Mastermind 44965 points

    Hi Ryan,

    Attached configuration is possible, however each OUTx can support 1Arms. Furthermore if customer want to drive two motors at the same time, probably thermal(Datasheet 9.3) could be issue. Probably customer is able to drive only one motor at the same time.

    Timing is controlled by internal logic since SPI is only way to drive ON/OFF output. Each protections works in parallel mode as well.

    If customer need to drive 2 motors at the same time, DRV8243 x 2 pcs could be alternative solution.

    regards

    Shinya Morita

  • 0 in reply to Shinya Morita
    TI__Expert 7495 points

    Shinya,

    Do you mean even DRV8908-Q1 can support 1Arms for each OUTx, but it cannot support 8Arms for 8 OUTx for thermal concern? Even it is not in parallel mode?

  • 0 in reply to Ryan Wang
    TI__Mastermind 44965 points

    Hi Ryan,

    1Arms is current capability for each channel. Device cannot support 8Arms for 8 OUTx.2 major limitations.

    - 6A maximum paralleled outputs (as datasheet page 1). Note that this is limitation for peak current. This does not mean DRV8908 can operates 6A continuous. 

    - Thermal should be limitation (Datasheet 9.3)

    Thermal is very common limitation for multi channel motor driver. Not only DRV89xx, but also other motor drivers.

    This drive is suitable for application what each motors are turning on in different timing.

    regards

    Shinya Morita

  • 0 in reply to Shinya Morita
    TI__Expert 7495 points

    Shinya,

    Great thanks