• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 47 subscribers
  • Views 1316 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.

Original question:

INA240: DC motor current sensing to check if the motor is stuck using either INA240 or INA181

INA240: DC motor current sensing using INA240 or INA181?

XIYANG YEH
Prodigy 10 points

Part Number: INA240
Other Parts Discussed in Thread: INA181, DRV8871

Hi, I am looking at brushed dc motor application with closed loop current control. The driver chip would be DRV8871 driven at 12V or 24V. I understand that INA240 would fit well for inline current sensing. I am wondering if INA181 can also be used for inline current sensing since the common mode voltage goes up to 26V? Thanks.

  • 0
    TI__Mastermind 26335 points
    Hello Xiyang,

    Thanks for considering to use Texas Instruments in your design. We are looking into your issue and will have a response for you on the following business day (Monday, U.S.A Mountain Time).
  • 0 in reply to Patrick Simmons
    TI__Mastermind 36730 points

    Hi Xiyang,

    The PWM at the motor winding can be as low as one diode drop below ground. This PWM is also experienced by the inline current sensing amplifier. Since the MIN common mode voltage spec for INA181 is -0.3V, the diode drop is very likely lower. Which may result in potential damage to INA181 input pins. This would be a top concern.

    To a lesser degree, we need to look at common mode settling time requirement. For this you may refer to figure 32 in the datasheet.

    Regard, Guang