Other Parts Discussed in Thread: BQ25629
Dear Sirs and Madams,
We are considering a system using BQ25629EVM.
The basic configuration is the same as the simple configuration of the datasheet.
We are supplying 5V to VBUS and checking the VSYS voltage, but the ripple voltage of VSYS voltage changes greatly depending on whether there is a battery or not.
< Connect the battery to the BAT terminal >
When the current input limit of BQ25629 is exceeded, current is also supplied from the battery, so no output voltage drop occurs when the load current increases.
The ripple voltage of VSYS is also low and stable from 10mV to 20mV.
< No battery, the BAT terminal is open >
Especially large ripple voltage was observed from 100mA to 250mA.
We found that the ripple voltage increases when the battery is not connected.
We thought that the PFM operation was the issue, so We set the "PFM_FWD_DIS" and "PFM_OTG_DIS" registers, but there was no improvement.
Do you know how to suppress ripple voltage when the battery is not connected?
Regards,
MM
