BQ76942: How to cascade using BQ76940

Kevin Xiong

Part Number: BQ76942
Other Parts Discussed in Thread: BQ76940, , BQ76930

Hi,

I want to manage 20 cells using BQ76940. But this chip can only manage 10 cells. How to cascade to manage 20 cells using BQ76942?

Thanks.

Kevin Xiong

0 Matt Sunna over 3 years ago

Hi Kevin,

Your image is not showing for some reason. When stacking more than one BQ76942, we recommend using low side FETs. This video from the 2020 BMS Deep Dive goes through an example stacking with the BQ769x2 family (start around the 20:00 mark): https://training.ti.com/how-stack-non-automotive-protectors-and-monitors-high-cell-count-applications

Here is the application document for using low-side FETs with the BQ76942: https://www.ti.com/lit/an/sluaa84/sluaa84.pdf

This TI Reference Design uses 2 BQ76930 device for a 20S solution. You can use many ideas from this example: https://www.ti.com/tool/TIDA-01093

I hope this is helpful.

Best regards,

Matt

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