0-35V Variable Power Supply Using XL4015 DC-DC Converter

0-35V Variable Power Supply Using XL4015 DC-DC Converter (Last Updated On: January 17, 2019)

DIY Variable Power Supply Using XL4015:

In this post we will design a Variable Power Supply Using XL4015 DC-DC Buck Converter Module. The Variable output voltage is 1.25 Volt to 35 Volt and Current ranges from 0-5 Ampere. We can also design power supply using LM317T adjustable power supply IC but the output sometimes get fluctuated and isn’t stable. But XL4015 output is very accurate and the output is stable. The best part about is that there is no need of PCB designing neither you need many electronics components as it already comes with a module.

Components Required:

1. 5A XL4015 DC-DC Adjustable Step-Down Power Module – (Buy Online From Amazon)
2. 230V to 30V step down transformer
3. Fuse 5A
4. 4 1N4001 Diode
5. 470uF Electrolytic Capacitor
6. 0.1uF Capacitor

XL4015 DC-DC Adjustable Step-Down Power Module:

0-35V Variable Power Supply Using XL4015 DC-DC Converter

The XL4015 is a 180 KHz fixed frequency PWM buck (step-down) DC to DC converter, capable of driving a 5 Ampere load with high efficiency, low ripple and excellent line and load regulation. Requiring a minimum number of external components, the regulator is simple to use and include internal frequency compensation and a fixed-frequency oscillator. The PWM control circuit is able to adjust the duty ratio linearly from 0 to 100%. An over current protection function is built inside. When short protection function happens, the operation frequency will be reduced from 180KHz to 48KHz. An internal compensation block is built in to minimise external component count.


1. Module Properties: Non-isolated step-down module (BUCK)
2. Input voltage: 4-38V (input please try not to exceed 38V)
3. Output voltage: 1.25-36V continuously adjustable
4. Output Current: 0-5A
5. Output Power: 75W
6. Operating temperature: -40 to +85 degrees
7. Operating frequency: 180 kHz
8. Conversion efficiency: up to 96%
9. Load regulation: S (the I) ≤0.8% (input 24V, output 12V, load change from 1 ~ 4.5A measured)
10. Voltage Regulation: S (U) ≤0.8% (output 12V, when 4A, voltage changes from 18 ~ 32V measured)
11. Power Indicator: Yes
12. Short circuit protection: Yes (limited current 8A)
13. Over-temperature protection: Yes (automatic shut off the output after overtemperature)
14. Connection: Welding, V-IN is the input, V-OUT output


1. It can be used for step-down voltage with input higher the output voltage, such as batteries, power transformers.
2. DIY adjustable power supply
3. Industrial equipment buck 12V to 3.3V, 12V to 5V, 24V to 5V, 24V to 12V, 36V 24V to and so on.
4. LCD Monitor and LCD TV
5. Portable instrument power supply
6. Telecom / Networking Equipment

0-35V Variable Power Supply Circuit Using XL4015:

Circuit for 0-35V Variable Power Supply Using XL4015 DC-DC Converter

The module can take a power upto 38V as input but we have used 30V input. For this we need 230V to 30V step down transformer. The output of the transformer is given to input of Rectifier Diode as shown in the figure above. The output of diode is then directly supplied to input of XL4015 Module. But before that we have used two Capacitors which are used for waveform smoothing or removing any ripples or unnecessary signal. Now the final output can be taken from output of XL4015 Module.

Thus this is the simple DIY Variable Power Supply Circuit that can easily be designed at home and used for multiple applications.

Video Tutorial & Explanation:

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