Review and Feedback Request: Battery Management Circuit with AXP209

[amanj1]

Hello EEVblog community,

I hope this message finds you all well. I am currently working on a project involving a multi-effects device, and I’ve designed a power supply and battery management circuit using the AXP209 power management IC. I would be deeply grateful if you could take a look at my schematic and provide your valuable feedback regarding its correctness and potential areas for improvement.

Project Details:
Primary Goals:
Power the system from USB when connected.
Manage and charge a 3.7V Li-ion battery when USB is available.
Ensure proper battery monitoring and safe charging.
Key Components Used:
AXP209: As the primary PMIC.
Sufficient decoupling capacitors for VBUS, ACIN, and other critical points.
A 0.02Ω resistor for battery current sensing.
Specific Questions/Concerns:
Are there any potential issues with the connection of BAT and BAT_SENSE, particularly the placement of the current sense resistor (R5)?
Does the decoupling around ACIN, VBUS, and VIN look adequate?
Are the configurations for the LDO outputs (e.g., LDO1, LDO3) and the associated capacitors appropriate for stable operation?
Are there any additional considerations for thermal management, ground plane design, or signal integrity (e.g., I2C lines to the microcontroller)?
Additional Note:
I’m a beginner in electronics, so I sincerely hope your guidance can help me learn and develop a deeper passion for this field. Your support will mean a lot to me and will surely inspire me to dive deeper into the world of electronics.

Attached Files:
I have attached the schematic for your review. Please let me know if additional details or design files are needed.

Your feedback will be invaluable in ensuring the reliability and performance of this design. Thank you in advance for your time and assistance!
Kind regards,
Electronics Enthusiast