BQ25157: SW reset and fast charging

Hi Alireza,

Alireza Asvadi said:

Based on the datasheet, the registers should reset to their default values. However, it appears that during this reset process, the output shuts down momentarily, which causes the microcontroller to stop functioning. Is this expected behavior, or could something else be triggering the shutdown?

Can you please confirm what kind of reset you are referring to? Is this an /MR driven hardware reset, a Watchdog driven software reset, an I2C driven HW or SW reset?

Alireza Asvadi said:

The fast charging current is defined as ICHG_CTRL × 1.25 mA. To achieve a charging current of 170 mA, I set ICHG_CTRL to 0x88. However, the actual charging current never exceeds 84 mA. When ICHG_CTRL is set below 0x43, the current adjusts correctly, but increasing it beyond 0x43 has no effect—the current remains capped at 84 mA. According to the datasheet, with ICHARGE_RANGE = 0, it should be possible to reach up to 318.75 mA, yet I’m only able to reach 84 mA. Could there be another limiting factor involved?

There can be several limiting factors for the charge current including CV current reduction, ILIM, input VINDPM and IINDPM. Can you please share your input voltage as measured at the VIN pin, your BAT voltage as measured at the VIN pin, and your STAT/FLAG register values while you are trying to charge?

Best Regards,

Juan Ospina

For reset, I am sending below command

write(BQ25157_ICCTRL0, 0x01)

write 0x1 to CCTRL0 register using I2C,

But for second question there was a mistake in the datasheet, the default value is 0x1 not 0x6., so I fixed it 

 

Thank you for the clarification. Can you please provide a few more details of the device operation when the SW Reset takes place?

A register log before the reset as well as VIN, VBAT, and any loads applied to PMID or LDO at the time of reset would also help to understand the cause of the momentary shutdown behavior.

Best Regards,

Juan Ospina