• State
  • Locked Locked
  • Replies 6 replies
  • Subscribers 47 subscribers
  • Views 157 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.

LMP8481: LMP8481

AN A
Prodigy 10 points
Part Number: LMP8481

Tool/software:

Hello TI team,
I am currently working on Battery Management System(BMS) project and using the LMP8481MM high-side current sense amplifier(Bi-directional) for current measurement. However, i am facing repeated current sensing failures during operation.

I would appreciate guidance on the following:

1.What are the common failure modes of the LMP8481 in such applications?

2.Are there recommended protections or design considerations for high-side sensing in BMS?

3.Is there any known issues with input differential voltage limits or transient spikes that could damage the part?

4.How can i debug whether the issue is due to the amplifier, shunt resistor(0.0003ohm) ?

Thanks in advance for your support!.

  • 0
    TI__Mastermind 32340 points

    Hello AN,

    Can you explain what your conditions are for the LMP8481?  

    AN A said:

    1.What are the common failure modes of the LMP8481 in such applications?

    Normally I have seen general failures of most of our devices not just your specific application when an Absolute Maximum Rating is over looked during normal operation or during startup.  

    AN A said:
    2.Are there recommended protections or design considerations for high-side sensing in BMS?

    Normally I would like to narrow down where the protection is required.  Is it the inputs that need protection?  Is it the supply voltage?  Is it one of the other pins.

    AN A said:
    3.Is there any known issues with input differential voltage limits or transient spikes that could damage the part?

    This is basically the same response from question #1.  Any transients beyond the Absolute Max could be the issue.

    AN A said:
    4.How can i debug whether the issue is due to the amplifier, shunt resistor(0.0003ohm) ?

    What is the exact failure?  Is the device getting damaged?  If so does replacing the LMP8481 fix the issue.  Does the supply current change?  Does the input bias current change?  Can you share any schematics to see what can be done to narrow down the issue and possible describe what you have already tested or probed the a DMM or scope.

    Regards,

    Javier

  • 0 in reply to Javier Contreras4
    Prodigy 10 points


    I shared the schematic..

  • 0 in reply to AN A
    TI__Mastermind 32340 points

    Hello AN,

    What exactly is the failure?  The schematic looks fine except you will get some additional gain error due to the IB current at the inputs but should not be much.  What is the AVdd?  What is the VCM voltage, or voltage of node where  R3, R228, C137 connect.

    Regards,

    Javier

  • 0 in reply to Javier Contreras4
    Prodigy 10 points

    Please respond to my private message..

  • 0 in reply to AN A
    TI__Mastermind 32340 points

    Will update this post once resolved.

  • 0 in reply to Javier Contreras4
    TI__Mastermind 32340 points

    Hello AN,

    I will close this post please reply if you require further assistance.

    Regards,

    Javier