• State
  • Locked Locked
  • Replies 6 replies
  • Subscribers 64 subscribers
  • Views 224 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.

BQ76952EVM: Taking high current

Nick
Intellectual 672 points
Part Number: BQ76952EVM
Other Parts Discussed in Thread: BQ76952, BQSTUDIO

My EVM board is taking high current ( more than 150mA). I checked the resistance between TP2 and VSS. It is coming around 70 ohm. 

Does it mean AFE is damaged ?   I connected the DSO on SDA & SCL pins  before supplying DC on BAT+ and BAT-. Does it damaged the AFE  or something else?

Thanks

  • 0
    TI__Expert 4085 points

    Dear Nick,

    I've got a few questions:

    1. Is the 70ohms during SHUTDOWN, when the device is in NORMAL mode, or completely unpowered?

    2. How much exact current are you drawing? Is there a load attached?

    3. What voltage are you applying at BAT+ and BAT-?

    It seems unlikely that attaching a DSO and then an power supply could cause damage unless the wrong pins were used.

    Best,

    Asher Nederveld

  • 0 in reply to Asher Nederveld
    Intellectual 672 points

    1. Is the 70ohms during SHUTDOWN, when the device is in NORMAL mode, or completely unpowered?

    70 ohm is when board is completely unpowered. No supply connected

    2. How much exact current are you drawing? Is there a load attached?

    No load attached.  @ 15v, board is drawing 116 mA. 

    3. What voltage are you applying at BAT+ and BAT-?

    I applied ~ 25V DC. Once EVM started drawing high current, I reduced to 15V DC

  • 0 in reply to Nick
    TI__Expert 4085 points

    Dear Nick,

    That is not a normal value for the resistance between VSS and TS2 when the device is unpowered. When we measure it on our devices, we are seeing a resistance of ~30 Mohms. Could you try to soldering on a new BQ76952 chip to see if the same issue occurs?

    Best,

    Asher Nederveld

  • 0 in reply to Asher Nederveld
    Intellectual 672 points

    Yes BQ76952 was damaged.  What could be the reason for it to get damage? 

  • 0 in reply to Nick
    TI__Expert 5645 points

    Hi Nick, 

    Today is the 4th of July US Holiday, so the team is out of office. We will get back to you on July 5. 

    Regards, 

    Arelis G. Guerrero 

  • 0 in reply to Arelis Guerrero
    TI__Expert 4085 points

    Dear Nick,

    Just to clarify, was the replacement also damaged or was it just the first one? Since you are using the EVM, which pins have you used the jumpers on to connect? My first thought is that it could be an issue with ESD damage.

    Would you mind connecting your EVM to BQStudio and seeing if there are any faults triggering when the device is powered?

    Best,

    Asher Nederveld