BQ76952EVM: Setting the OCD1 value in BQstudio fro BQ76952evm

Criton Kallkkaran

Part Number: BQ76952EVM
Other Parts Discussed in Thread: BQ76952, BQSTUDIO

Tool/software:

Hi Team,

I am trying to simulate over current discharge fault for bq76952 by setting the OCD1 value in the protections tab in Data memory. I could find that the minimum value that could be set in the register is 4mV. From my understanding for a sense resistor of 0.001 Ohms the current discharge threshold should be 4A for 4mV set in the OCD1 register. However the BQstudio triggers the fault when my programmable load reaches 3.4 Amps. Could you please tell me if my math is correct. I have attached the images of BQstudio for your reference.

Many thanks,
Criton

8 months ago

0 Abhijith V Narayan 8 months ago

Intellectual 446 points

Hi Criton,

Yes your calculation is correct. But have you calibrated the current? See section 2.6 of BQ769x2 Calibration and OTP Programming Guide.

In bqStudio > "Registers" tab, can you check if the CC2 current is accurate? You may load the system to say 2A and check if the CC2 and the load bank reads the same?

Regards,

Abhijith

0 Alexis_H 8 months ago in reply to Abhijith V Narayan

TI__Genius 17755 points

Hello Criton,

Your calculation is correct. Section 7.26 Comparator-Based Protection Subsystem (continued) in the BQ76952 Datasheet shows the accuracy values for overcurrent protection.

If you would like it to be more accurate, we recommend increasing the sense resistor value and experimenting with the thresholds to meet your satisfaction.

Best Regards,
Alexis

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BQ76952EVM: Setting the OCD1 value in BQstudio fro BQ76952evm