BQ76940: OCD and SCD setting

keshava hv

Part Number: BQ76940
Other Parts Discussed in Thread: BQ78350-R1

Hello,

we are using BQ76940 along with BQ78350-R1 in our design, our BMS requires to operate at high Charge and Discharge Currents, but the BQ78350-R1 is allowing to set OCD to 30A max where as we need to operate up to 500A Max will the current sensor in AFE supports the current rate or should we change for external current sensor.

if AFE BQ76940 supports should we do any changes in the configuration of the Companion Controller BQ78350-R1

Kindly Suggest

over 5 years ago

0 WM5295 over 5 years ago

TI__Guru 54715 points

Hi Keshava,

The BQ78350-R1 current range has a limit of 32767, normally this is mA or 32.7A. There is the IPScale feature to use multiples of 10, but it does not work well in -R1. BQ78350-R2 is available for download which handles IPScale better. You would lose resolution in the current but it provides a mechanism to read over the interface that the current is scaled.

Another option is to scale the sense resistor and calibrate at a different current. In this case you must communicate to the using systems what the current values mean. You might look at this document on scaling in gauges. https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/180/3465.Gauge-Design-Configurations-for-High-Charge--Discharge-Rate-Applications.pptx

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BQ76940: OCD and SCD setting