BQ25723: 4S input voltage divider pin selection.

Sean DiGiovanni

Part Number: BQ25723
Other Parts Discussed in Thread: TIGER

I am using the BQ25723 in my design and am not getting the desired I2C feedback. I am currently using a voltage divider connected to the CELL_BATPRESZ pin that is measuring the divided voltage of the VDDA to ground.

1) What should the voltage be at the VDDA pin when the battery is connected and then again when removed?

2) what should the voltage be at the CELL_BATPRESZ pin when the battery is connected and again when removed?

My VDDA voltage remains constant with or without the battery.

4 months ago

0 Tiger Zhou 4 months ago

TI__Mastermind 36505 points

Hi, Sean,

VDDA is the same as REGN voltage =6V, with or without the battery. The CELL_BATPRESZ pin should be a ratio of the REGN, 75% of 6V for 4S configuration.

Regards,

Tiger

0 Sean DiGiovanni 4 months ago

Prodigy 40 points

I am reading 4.5 VDC at the CELL_BATPRESZ pin, but only 12.7VDC at the battery with no current flowing into the battery. 13.1VDC at VSYS

0 Tiger Zhou 4 months ago in reply to Sean DiGiovanni

TI__Mastermind 36505 points

This is normal.

0 Sean DiGiovanni 4 months ago in reply to Tiger Zhou

Prodigy 40 points

I need to charge a 4S battery to 16.8 VDC. How do I program the IC to output that voltage?

0 Tiger Zhou 3 months ago in reply to Sean DiGiovanni

TI__Mastermind 36505 points

HI, Sean,

You can set the max charge voltage to 16.8V. The charger will charge the battery to that level. For more details, please check the BQ25723 datasheet and user guide.

https://www.ti.com/tool/BQ25723EVM

Regards,

Tiger

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BQ25723: 4S input voltage divider pin selection.