• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 64 subscribers
  • Views 217 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

BQ76925: BQ76925 with 100 micro ohm shunt.

Vasu Poojary
Intellectual 390 points
Part Number: BQ76925
Other Parts Discussed in Thread: BQ76942

Hello,

We are considering to use BQ76925 for 4 cell Li-ion monitoring and planning to use it with 100 micro ohm shunt to meet the monitor current above 100A till 800A.

We do not want to have SOC/SOH feature so measuring battery current at lower current is not crucial for us.

Do you see any challenge here ?

During operation we want to keep system in standby mode (Not sleep mode ) to reduce the system current consumption , How BQ76925 can be woken up from standby mode ?

Thanks

regards

Vasu

  • 0
    TI__Expert 3325 points

    HI Vasu, 

    The 100uOhm shunt resistance should be okay in this case.

     You can wake up the device from standby mode by clearing the POWER_CTL bits, you can refer to Table 14. Reference Voltage Selection in the DS for details of each register. 

    Standby mode is really just having a particular set of conditions enabled/disabled and are further specified in Section 7.5 Electrical Characteristics: Supply Current in the DS. So there is no real method for wake from standby other than simply re-enabling functions needed during normal use. 

    Before considering BQ76925, is there any reason why you would not want to go with our latest monitor BQ76942?

    This is our 3-10s monitor with cell balancing and standalone or autonomous mode for fault recovery and protection. It has far better performance features that include 4 power modes (normal, sleep, deepsleep, shutdown) for the best flexibility along with many integrated protection features (I/V/T) with far better accuracy. 

    Best, 

    -Luis Torres

  • 0 in reply to Luis Torres
    Intellectual 390 points

    Thanks for quick reply.

    Mainly cost is the driving factor to go for BQ76925 ,  Our application is 4 cell BMS without SOC, SOH.

    Expecting setting low current threshold to wake up the BQ76925, is this possible with BQ76925 ?

    By above your application it seems we need to keep both BQ and Host in active status to monitor the fault .

    Thanks

    Vasu

  • 0 in reply to Vasu Poojary
    TI__Expert 3325 points

    Hi Vasu, 

    As previously mentioned, the 'wake up' of the circuit is more about what features you have enabled/disabled in the POWER_CTL register. There would not be a current threshold that would need to be set in order to wake the device. Instead you will need to clear the bits of the POWER_CTL register to enable the features that you are needing, at that point it would be in a normal operating state. 

    Hopefully I understood your question, feel free to clarify if it did not answer your question. 

    Best, 

    -Luis Torres