BQ24295 questions

Hello Frank,

Did you read REG09 two times consecutively as per the last two lines of 8.3.4.2?

Also, when you read REG08, what value do you get?


Regards,
Joel H

Hi Joel,

For REG08, the first conditon is bit 4,5 is [1 1], charge termination done. Thank you.

BR
Frank

Hey Frank,

1. When the battery is fully charged, the INT pulse only happen once, but from the datasheet, the INT pulse should be continuous.( we read the REG09, it's 0x00)

Just to confirm, you read 0xB4 from REG08 when the battery is at full charge and you receive the INT signal, correct?

I also want to confirm, you are reading the REG09 twice correct?


2. When we remove the battery when charge or finish charging, the INT will trigger every 256us, the REG09 is 0x00 too. Why? From the datasheet, the INT trigger shouldn't be continuous.

Do you see an INT pulse that lasts 256us or does INT happen every 256us?

Also, are you only charging the battery, or do you have a system you are powering as well?


3. We also test the State pin, but the frequency is 20hz not the 1Hz.

The STAT pin oscillating at 20Hz could indicate changing between termination and charge. Does STAT blink at 20Hz when the battery is attached or removed?

Hi Joel,

Could you please help me check the questions? It's a urgent case. Thank you.

BR
Frank

1. When the battery is fully charged, the INT pulse only happen once, but from the datasheet, the INT pulse should be continuous.( we read the REG09, it's 0x00)

When the device completes the charge cycle, it will only generate a single INT pulse that is 256us in duration. Every time you terminate charging it will pull the INT low, but not continuously. If you want a good indication of charge complete, use STAT when the battery is in. 

2. When we remove the battery when charge or finish charging, the INT will trigger every 256us, the REG09 is 0x00 too. Why? From the datasheet, the INT trigger shouldn't be continuous.

The INT will be continuous when you remove the battery. Even without a battery, when the device has charging enabled, the internal buck converter will regulate to a set voltage minimum, and then droop again as it is loaded on, restarting a "charge cycle" until the load causes the voltage to droop. This drop in system voltage will restart the charging converter and continue to throw the INT as if though you were charging and discharging. This device does not have a way to tell if the battery is present or not. Only your system voltage dropping and coming back up is a good indicator. 

3. We also test the State pin, but the frequency is 20hz not the 1Hz.

What you are seeing the device going into and out of sleep/termination state and charge state due to the battery being removed. 

Overall, the device is working properly. 

Hope this helps,

Joel H