• State
  • Locked Locked
  • Replies 5 replies
  • Subscribers 63 subscribers
  • Views 320 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.

BQ76952: BQ76952

Mohit Aggarwal
Prodigy 90 points
Part Number: BQ76952

Hello TI Team

We are BQ76952 AFE for BMS application and facing one issue regarding Short Circuit.

We are using BQ76952 IC and in our system we are controlling low side mosfet and also current sensing will be done by afe only.

Using DDSG pin we are controlling our DFET MOSFET So during Short circuit we have seen that DDSG pin is going down but after 4 ms it becomes high and also we have found that all temperature which is connected to afe becomes 0 and also at the same time fullscan bit also becomes 0 for around 200msec. 

Also we have probe all AFE VBAT,REG1,REG18,REGIN all are expected only 

For your reference i have attached word file also please check that one also and also please help us how we can debug the issue.

BMU SC TEST.docx

  • 0
    TI__Mastermind 42060 points

    Hello Mohit,

    Could you share your schematic? Do you have waveforms of the short-circuit?

    Could you probe SRP to Vss and SRN to Vss?

    Best Regards,

    Luis Hernandez Salomon

  • 0 in reply to Luis H. S.
    Prodigy 90 points

    Hi Luis 

    Its diffircuit to probe SRN AND SRP because its a very small signal (When we are using CRO we are getting noise so unable to Probe that )

    Also can please help in debugging 

    When we are doing Short circuit at that time all the temperature which is connected to afe becomes 0 .Is there any way to check why this is happening from hardware or software point of you

    Also is there any hardware point to debug short ciruit issue other then SRP SRN

    Thanks and Regards

    Mohit Aggarwal

  • 0 in reply to Mohit Aggarwal
    TI__Mastermind 42060 points

    Hello Mohit,

    Can you share the schematic? Do you have capacitors from SRP to Vss and SRN to Vss?

    After DDSG goes high, does it go back down again?

    Do you have a .gg.csv file of your settings?

    Best Regards,

    Luis Hernandez Salomon

  • 0 in reply to Luis H. S.
    Prodigy 90 points

    Hi Luis 

    Find the attached Schematic of AFE Section 

    Yes we have capacitors between SRP to vss and SRN to VSS (O.1 uF)

    After DDSG goes high, does it go back down again?

    No DDSG Pin will not low we have to disconnect short circuit and then again connect at that time it will detect SC

    And find the setting of the afe

    REG0 Config = 0x01
    REG12 Config = 0xFD
    ALERT Pin Config = 0xAA
    DDSG Pin Config = 0xAA
    Default Alarm Mask = 0x4180
    7 pins used as Temp Sensors
    16 cell volts
    Enable Protections A = 0x80
    Enable Protections C = 0x40
    OCD1 Threshold = 0x02
    SCD Threshold = 0x02
    SCD Delay = 0x01 (0us)
    SCD Latch Limit = 0x01 (disable auto recovery)

    Thanks & Regards

    Mohit AggarwalPOWER BMU AFE.pdf

  • 0 in reply to Mohit Aggarwal
    TI__Mastermind 42060 points

    Hello Mohit,

    C104 and C105 should actually be on the SRP/SRN pins themselves, not before the filter resistor, could you try adding these to these pins and re-run the test? We have found similar issues like this during short-circuit testing if these capacitors are not placed on the pins. 

    Best Regards,

    Luis Hernandez Salomon