BQ76940: High-side current sense for BQ769x0

Dave Young

Part Number: BQ76940

Hi There-

I'm evaluating a few different parts for a large e-bike battery (14S15p). I may have to utilize a HASS 200-S hall effect current sensor thanks to other design constraints, but still want to use the BQ76940's overcurrent and undercurrent protections in addition to the AFE, gauging, and cell balancing features. Is there an easy way to spoof the SRN and SRP nodes to allow this configuration? I want to measure both charge current and discharge current, so if I just divide down the 0-5V signal from the sensor I'm not sure what the 0-current voltage level should be at.

Are there other ICs that I should be considering given this configuration?

Thanks!

Dave

over 6 years ago

0 Matt Sunna over 6 years ago

TI__Guru* 81035 points

Hi Dave,

I think this is the right IC for your application. If using a hall sensor, you will need to translate the output to meet the input levels of the BQ76940, but this is possible and I have heard from a few users who have done this. I am linking another thread where some questions were asked about interfacing with the BQ76940 inputs.

https://e2e.ti.com/support/power-management/f/196/p/730105/2696454

Best regards,

Matt

0 Dave Young over 6 years ago in reply to Matt Sunna

Intellectual 520 points

Thanks for the speedy reply! That certainly does help. Sorry it didn't come up in my search :( -- the original post used a different variant of the part.

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BQ76940: High-side current sense for BQ769x0