DIY XL4015 5V/5A USB Power Supply – Perfect for Raspberry Pi & More

Building a reliable 5V power supply is one of the most useful DIY electronics projects. Whether you’re powering a Raspberry Pi, a development board, or USB gadgets, stable 5V at high current is essential.

In this project, I designed and built a 5V/5A USB power supply using the XL4015 buck converter IC. The design includes reverse polarity protection, USB output ports, and indicator LEDs – making it a compact and reliable module.

🔹 Features

Input voltage: 8V to 36V DC

Output voltage: 5V fixed

Maximum output current: 5A

USB-A port output for powering Raspberry Pi, ESP32, Arduino, or mobile devices

Reverse polarity protection (SS1045 diode)

Power indicator LED

Stable output with low ripple (330 µF capacitor + ceramic filters)

Compact PCB design

🔹 Why Use XL4015?

The XL4015 is a popular DC-DC buck converter IC rated up to 5A output current. It provides high efficiency, thermal protection, and works over a wide input range (up to 36V). It’s ideal for projects where you need stable 5V from a higher DC input source like a battery pack, adapter, or solar panel.

🔹 Circuit Design

The circuit is based on the XL4015 datasheet reference with some improvements:

Input Section

220 µF electrolytic capacitor for bulk filtering

1 µF ceramic capacitor for high-frequency noise suppression

XL4015 Regulator Core

Inductor: 47 µH rated ≥6A

Schottky diode: SS1045 (10A, low drop)

Output capacitor: 330 µF electrolytic + ceramic for stable regulation

Feedback resistors set to fixed 5V output

USB Output Section

Standard USB-A connector

5V on VBUS, GND connected

Optional: resistor divider on D+/D– for fast charging detection

Reverse Polarity Protection

SS1045 diode in series with input to protect against wrong connections

Power LED

LED with 330 Ω resistor across 5V output

🔹 Bill of Materials (BOM)

Here are the key components used:

U1 – XL4015E1 buck converter IC

C1 – 220 µF input capacitor

C2, C3 – 1 µF ceramics

C5 – 330 µF output capacitor

L1 – 47 µH inductor (≥6A rating)

D1/U3 – SS1045 Schottky diode (10A)

R1, R2 – Feedback resistors (3.3k & 10k) for 5V output

USB1 – USB-A female connector

LED1 + R3 – Power indicator (330 Ω resistor)

U4 – SS1045 for reverse protection

(Fully detailed BOM table available above in Excel format)

🔹 PCB Design

The PCB was laid out with wide copper pours for the high current paths (input, diode, inductor, output).

Output traces ≥3.5 mm wide for 1 oz copper (safe for 5A).

Large copper pad under XL4015 (TO-263 package) for heat dissipation.

USB port mounted at the edge for easy access.

🔹 Use Case – Powering Raspberry Pi

A Raspberry Pi 4 typically needs 5V at up to 3A with peaks near 3.5A.

This module easily delivers 5V/5A, making it perfect for powering a Raspberry Pi plus some USB accessories.

It can also power:

ESP32/Arduino projects

LED strips (5V)

USB-powered gadgets

Small routers and SBCs

🔹 Future Improvements

Add a USB fast charging circuit (resistor dividers on D+/D–).

Upgrade to P-MOSFET reverse protection for higher efficiency instead of diode.

Optional polyfuse on USB output for extra protection.

🔹 Conclusion

This DIY XL4015 5V/5A USB power supply is a simple but powerful project. It’s stable, efficient, and versatile for many electronics applications. I’ve tested it with a Raspberry Pi, and it runs perfectly without undervoltage warnings.