BQ76952: OCD 1,2 and 3

Mohammed Suffiyan

Intellectual 461 points

Part Number: BQ76952

Hi team,

I want to understand the reason behind adding OCD 1,2 and 3, and what is COV Latch protection?

Thank You

over 3 years ago

0 Luis H. S. over 3 years ago

TI__Mastermind 42060 points

Hello Mohammed,

OCD 1/2/3 are used for protection against over-current during discharge. OCD 1 and 2 are triggered by voltage measurements across the sense resistor, OCD 3 is triggered by current readings from coulomb counter measurements (See Section 5.2.8 in the TRM).

COVL protection is triggered in the event of multiple COV protection events, each time COV triggers a counter increases, if triggered enough times in a programmed timeframe, COVL will trigger to allow for longer recovery times (See Section 13.6.3 in the TRM).

Best Regards,

Luis Hernandez Salomon

0 Mohammed Suffiyan over 3 years ago in reply to Luis H. S.

Intellectual 461 points

Hey Louis,

Thank you for your reply. Why OCD 1,2, and 3 is added if only OCD1 could do the job? Also if I enable all three OCD protections which one will take action, is there any priority setting among OCD1, 2, and 3 that I can set?

0 Luis H. S. over 3 years ago in reply to Mohammed Suffiyan

TI__Mastermind 42060 points

Hello Mohammed,

You could set different conditions with all of them, although they operate on the same principles. For each OCD you can set different minimum thresholds and a different time delay that is used to trigger the protection for the different current discharge protections. This is represented here (not-to-scale):

All of them are treated with the same authority.

Here is an older thread that explains how this works in further detail: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/975511/bq77905-protections-of-bq7790512

Best Regards,

Luis Hernandez Salomon

Power management

Power management forum

BQ76952: OCD 1,2 and 3