nPM1300 high voltage output at VOUT2 upon VBAT connection.

[xproto]

My lipo battery is at 3.86V and I measured 3.76V at VOUT2 which supplies the nRF52832.

I just based the design in the example circuits in nPM1300 datasheet.

I already reviewed the circuit but I don't see any problem based on example. Based on the VSET2 R it should output 3.3V.

[Parth Parekh]

I don't think it might be the issue with voltage ripple of buck output but I doubt the LFCLK might the issue here. 

To debug BLE disconnection issues related to the low-frequency clock (LFCLK) on the nRF52840, first verify that the LFCLK source is correctly configured in your code (preferably using an external 32.768 kHz crystal for accuracy). Enable detailed logging to capture BLE events and check if the LFCLK is running. Ensure the BLE connection intervals and supervision timeout are properly set, and monitor power management behavior to ensure the LFCLK isn't shut down. Use a logic analyzer or oscilloscope to check for clock stability or power supply ripple. If using the internal RC oscillator, enable periodic calibration to reduce drift. You can also switch between different LFCLK sources to isolate the issue. Check SoftDevice return codes, use Nordic's nRF Connect tools to analyze BLE packets, and perform clock drift tests to diagnose timing-related issues.

[xproto]

Thanks I got it working after I tested with the second board to compare after that with no changes the 1st board is working too. I'm really not sure what solved the problem aside from adding the addtl bypass capacitor. Both two board have 140mV ripple.

With the LFCLK, I used what I have been using with the previos project which works with nRF52DK and my custom board. 

CONFIG_CLOCK_CONTROL_NRF_K32SRC_20PPM=y