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BQ24195 status and I2C communiation

Mahendra Patel1
Expert 3560 points
Other Parts Discussed in Thread: BQ24195

Hello all,

I am attaching waveform of status pin on BQ24195. I am not able to find what kind of fault condition is occuring.

SYS, REGN and PMID output is observed but BAT output is not there, even if battery in good condition is connected.

Also, we are also failing to communicate over I2C with controller (SCL < 100kHz).

Kindly advice.

Thanks in advance!

Regards,

Mahendra Patel

  • 0
    TI__Expert 3160 points

    Mahendra, 

     

    Are you using the TI EVM in your set-up? Can you try with only VBUS and/or only VBAT supply and check communication?  I'd like to resolve the communication issue before we get into any other issues you're seeing.

     

    Thanks,

    Rachel 

  • 0 in reply to Rachel Moore
    TI__Expert 3560 points

    Thanks Rachel,

    It is a customer board & communication issue is now resolved.

    However we are currently facing issue with PMID output.

     On Power up, the uC Host write:  REG01 = 0x2B (to set REG01[5:4] to 10) & REG05= 0x08, all other REG in default setting

    1.  Only Battery is Connected

    2.  Battery Voltage is 3.7V (Battery is NOT Low)

    3.  REG01[5:4] is made 10

    4.  As charger (VBUS) is not connected, OTG Pin is HIGH.  Only battery is connected.

     * But we are not getting 5V on PMID pin

    * Boost switching is not seen.

     Please see below REG readings,

    REG00 Reading = 0x37, Should be default value = 0x30 DOUBTFUL

    REG01 Reading = 0x2B (OK)

    REG02 Reading = 0x60 (OK, As per default)

     REG03 Reading = 0x11 (OK, As per default)

     REG04 Reading = 0xB2 (OK, As per default)

    REG05 Reading = 0x8A (OK)(watch dog disabled)

     REG06 Reading = 0x03 (OK, As per default)

    REG07 Reading = 0x4B (OK, As per default)

    REG08 Reading = 0x00 (DOUBTFUL Bits 7,6,3,2)

    REG09 Reading = 0x80 (Watchdog expiry error even when WDT is disabled.

    REG0A Reading = 0x23 (OK)

     I hope this information would be enough for you to guide us forward.

     Regards,

    Mahendra Patel

  • 0 in reply to Mahendra Patel1
    TI__Expert 3160 points

    Mehendra,

    Your register set-up looks correct, but you are right that REG08  and REG09 are not displaying expected values.  

    Please try to read-back twice before recording the REG09 status.  Previous fault bits are not cleared until the second time your read the register so it maybe possible the watchdog fault is old data. 

    In addition to writing REG01=0x2b, also make sure the OTG pin is in the right state. If you are using the USB-to-GPIO box and the TI GUI software you can un-check the box shown below:

    Thanks,

    Rachel