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BQ40Z80: No usage of protections features

Part Number: BQ40Z80

Hello TI Support,

I have a 3S Li-Ion battery pack and I would like tu use the BQ40Z80 only for cell balancing and gauging, avoiding protections features (protections are already performed by other components).

First of all: is it possible to use a BQ40Z80 in this way? If yes, can I leave the DSG and CHG pins floating? Can I connect VCC to Batt+?

Thank you for your support, regards

Stefano

  • Hello Stefano,

    You can set the protection thresholds such that those protections are never triggered.

  • Hello Shirish,

    thank you for your reply. In order to save space on my board I would like to avoid all protection Mosfets. I wonder if I can just do not connect all the related pins of the BW40Z80: pin 26 DSG, pin 28 PCHG, pin 29 CHG.

    Furthermore I wonder if it is ok if I connect pin 24 VCC to BATT+ instead "Connect to the middle of protection FETs through the series resistor."

    Thank you for your support.

    Stefano

  • Hello Shirish,

    thank you for your reply. In order to save space on my board I would like to avoid all protection Mosfets. I wonder if I can just do not connect all the related pins of the BW40Z80: pin 26 DSG, pin 28 PCHG, pin 29 CHG.

    Furthermore I wonder if it is ok if I connect pin 24 VCC to BATT+ instead "Connect to the middle of protection FETs through the series resistor."

    Thank you for your support.

    Stefano

  • Hello Stefano,

    It should be fine not to use the protection FETs and leave the FET gate drive pins floating. Make sure the VCC is connected to the same node as the BAT pin (through the diode) since normally VCC would be through the body diodes of the FETs.

    Sincerely,

    Wyatt Keller