BQ27546-G1: Standalone working and Other queries

Baghiya Lakshmi

Part Number: BQ27546-G1

Hi,

We are planning to use BQ27546YZFT-G1 in our design as the Battery charger. As per my understanding from the docs, we can either operate the Battery charger in 15mins mode or 32 secs mode.
But in both modes, the system MCU has to take action before the timer times out.

Especially, in the 32sec mode, the timer reset has to be done every 32 seconds else the Battery charger would enter into High impedance mode. Is it possible to operate the Battery charger without much intervention from the MCU?

Also, Connecting the load before and after the current sense resistor - Whether it would impact the fuel gauge calibration?

over 2 years ago

0 Shirish over 2 years ago

TI__Guru 57697 points

An MCU is required. Since it will be present to read the state of charge from battery, the other actions are easy to implement.

The load current must flow through the current sense resistor. On the EVM, you connect the load to the pack pins.

0 Baghiya Lakshmi over 2 years ago in reply to Shirish

Intellectual 645 points

Hi Shirish,

The exact question is whether the Battery charger is needed to be reset in the 32 sec timer mode or the host mode for every 32 seconds.

0 Shirish over 2 years ago in reply to Baghiya Lakshmi

TI__Guru 57697 points

Hello Baghiya,

I am not sure if question is related to the gauge or the charger. Can you clarify?

For bq27546:

If a charger is attached, the host should immediately take the fuel gauge out of HIBERNATE mode before beginning to charge the battery. Charging the battery in HIBERNATE mode will result in a notable gauging error that will take several hours to correct. It is also recommended to minimize discharge current during exit from HIBERNATE.