BQ76940: Zener diodes needed for external cell balancing required?

Eohan George22

Part Number: BQ76940

In the EVM reference design http://www.ti.com/lit/ug/slvu925c/slvu925c.pdf on page 45, are the zener diodes D6-D15 really required ? The Pchannel FET does have a back to back zener for protecting the gates. Does the circuit function as effectively and robustly without the diodes D6-D15 ?

over 6 years ago

0 Matt Sunna over 6 years ago

TI__Guru* 81035 points

Hi,

There is a more detailed description of the role of the zener diodes in the BQ769x0 Top 10 Design Considerations app note. See the sections on Cell Balancing and Random Cell Connections http://www.ti.com/lit/an/slua749a/slua749a.pdf

Once you understand the conditions the zeners are intended to protect, you can decide whether to include them in your system. Generally, they are recommended for most systems.

Best regards,

Matt

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BQ76940: Zener diodes needed for external cell balancing required?