BQ4050: Battery Protection and Monitoring, Hibernation, Cell Balancing, Smart Charging

Dan1

Part Number: BQ4050
Other Parts Discussed in Thread: BQ40Z50, , BQ2980, BQ77915, BQ25710, EMB1499Q, EMB1428Q

Hi,

The following E2E thread lead me to BQ4050 and BQ40z50. Can I please have some help with the implementation?
https://e2e.ti.com/support/power-management/f/196/t/871568

Hibernation

We need our battery protection IC to be able to open the charge and discharge FETs on command from the MCU, or in there is a fault. The protection IC should then keep the load removed until a charger is connected. e.g. the same as BQ2980 and BQ77915

It looks like the BQ4050/BQ40z50 ManufacturerAccess() MAC Shutdown feature will do exactly this. (1) Can you please confirm?
Section 5.4.2 on page 41 - www.ti.com/.../sluuaq3.pdf

(2) The Technical Reference manual linked above is for BQ4050, but does it also apply to BQ40z50?

System Present vs Shutdown

The SHUTDN and PRES features share a pin. (3) How do we select which feature we want to use? I couldn't find it in the datasheet.

(4) Do we need the SHUTDN feature enabled (System Present disabled) in order to use the ManufacturerAccess() MAC Shutdown feature, or is that a separate thing?

Smart Charger

We are considering BQ25710 as our smart charger because of its OTG capability. (5) In order for BQ4050/BQ40z50 and BQ25710 to interact, do they just need to be on the same SMBus, or are there more steps involved?

This is mentioned on page 24 of the BQ4050/BQ40z50 datasheets.
"Reports the appropriate charging current needed for constant current charging and the appropriate charging voltage needed for constant voltage charging to a smart charger using SMBus broadcasts" https://www.ti.com/lit/ds/symlink/bq4050.pdf#page=24

(6) How do BQ4050/BQ40z50 know what voltage and current to negotiate with BQ25710 in smart charging?

Active Balancing

(7) Can the built-in passive balancing in the BQ4050 and BQ40z50 be disabled by an MCU?

I’m told that BQ4050/BQ40z50 can be connected with EMB1428Q and EMB1499Q to add active balancing but looking through the datasheets, it doesn’t look like BQ4050/BQ40z50 have the right pins to interact with EMB1428Q/EMB1499Q. (8) How would they connect?

Kind regards,

over 5 years ago

0 Andy Liu (BMS) over 5 years ago

TI__Guru 52115 points

Hi Daniel,

I see you posted quite a few questions. I would need some time to prepare the answers.

Andy

0 Kang Kang over 5 years ago in reply to Andy Liu (BMS)

TI__Mastermind 24870 points

The TRM for the bq4050 and bq40z50 are similar. For common functions, it should be the same, however, here is the TRM for bq4050:

http://www.ti.com/lit/ug/sluuaq3/sluuaq3.pdf (bq4050)

http://www.ti.com/lit/ug/sluubu5a/sluubu5a.pdf (bq40z50-R3)

Feature selection is dependent on your system. You will need to refer to the TRM, test it on the EVM and determine what feature you need and how that feature works.

The passive balancing is disabled, this is simply searched in the TRM. Just disable balancing bit.

0 Dan1 over 5 years ago in reply to Kang Kang

Intellectual 865 points

Thanks Andy,

I look forward to your response :)

Thanks Kang,

You answered my question about the TRM for BQ40z50 (2) very well but I couldn't accept your answer as a solution to this thread since the other questions are still unanswered. Question (3) was about how to configure the IC, not about which feature I need for my application. Thank you though :)

Kind regards,

0 Kang Kang over 5 years ago in reply to Dan1

TI__Mastermind 24870 points

Hello Dan,

You can disable balancing by not enabling balancing. We have this command on both the bq4050 and the bq40z50-Rx.

Power management

Power management forum

BQ4050: Battery Protection and Monitoring, Hibernation, Cell Balancing, Smart Charging

Hibernation

System Present vs Shutdown

Smart Charger

Active Balancing