BQ27426: Schematic Review

Hi team,

Any feedback for this, Thanks.

Brs

Jayden

Yes, please email me the schematics.

Hi Dominik,

I have email to you! Thanks. Also attached as below.

The schematic of BQ27426 is as below:

• BATCx_VDD: Connect to Battery+;
• S3850: jumper terminal;
• GND: Battery-；
• LSx_BAT：Connect to VSYS；
• SCL/SDA: Connect to AP,  Pull up to the system 1.8V IO power supply through a 2.2k resistor ; whether the 1-MΩ pulldown resistors is needed because there is a situation where the 1.8V IO port is powered off;
• GPOUT:  Connect to AP,  Pull up to the system 1.8V IO power supply ;
• BIN: The battery is embedded in the system; 10k pull down resistor to GND;
• R3851/R3861: 5mΩ resistor;
• SV3850/SV3860: 5V regulator tube;

 6327.Schematic Review.pptx

Pls feel free to let me know if any issues. Many Thanks.

Please make sure that the 2.2uF capacitor on VDD is not de-rated below 2.2uF at 1.8V over temperature (it's in a very small 0201 package and may not have 2.2uF at 1.8V over temperature).

Why do you use 2 gauges?

They use 2 gauges in foldable phone which has two batteries. And the capacity of the two batteries is not the same.

Are there any other issues in the schematic?

 whether the 1-MΩ pulldown resistors is needed because there is a situation where the 1.8V IO port is powered off?

Thanks.

Brs

Jayden

The I2C lines should not float, hence the 1MOhm pull-down are a good idea.

So the two batteries supply totally different circuits or how does this work?