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

We’ll make a variable power supply with the XL4015 DC-DC Buck Converter Module in this tutorial. The variable output voltage varies from 1.25 to 35 volts, with a current range of 0 to 5 amps. We can also use the LM317T adjustable power supply IC to create a power source, however, the output fluctuates and isn’t always reliable. However, the XL4015 output is quite accurate and consistent. The best aspect is that you don’t need to construct a PCB or buy any electronic components because it already comes with a module.

Components Required:

  • 5A XL4015 DC-DC Adjustable Step-Down Power Module
  • 230V to 30V step-down transformer
  • Fuse 5A
  • 4 1N4001 Diode
  • 470uF Electrolytic Capacitor
  • 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 with high efficiency, minimal ripple, and excellent line and load regulation that can drive a 5 amp load. The regulator is simple to operate and includes internal frequency compensation and a fixed-frequency oscillator, requiring only a few external components. The duty ratio can be adjusted linearly from 0 to 100% using the PWM control circuit. Internally, there is an overcurrent protection feature. The operation frequency is lowered from 180KHz to 48KHz when the short protection function is activated. To reduce the number of external components, an internal compensating block is included.


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


  1. It can be utilized in step-down voltage applications where the input voltage is higher than the output voltage, such as batteries and power transformers.
  2. DIY power supply that can be adjusted
  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 Monitors and LCD Televisions
  5. Power supply for portable instruments
  6. Telecom and networking gear

0-35V Variable Power Supply Circuit Using XL4015:

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

The module can accept a power supply of up to 38 volts, but we used 30 volts. For this, we’ll need a 230V to 30V step-down transformer. The output of the transformer is linked to the input of the Rectifier Diode, as shown in the diagram above. The output of the diode is then linked directly to the input of the XL4015 Module. Prior to that, two capacitors were used to smooth the waveform and remove any ripples or unwanted signals. The final output can now be accessed from the output of the XL4015 Module.

As a result, this is a simple DIY Variable Power Supply Circuit that can be built at home and utilized for a wide range of applications.


I hope all of you had understood how to design 0-35V Variable Power Supply Using XL4015 DC-DC Converter. We MATHA ELECTRONICS will be back soon with more informative blogs soon.

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