LM2596 DC Buck Converter Adjustable Power Supply with LED Voltmeter
LM2596 DC Buck Converter Adjustable Power Supply with LED Voltmeter
LM2596 DC-DC Step-Down Buck Converter with LED Digital Voltmeter Display
Take precise control of your DC power with this compact and efficient LM2596 Step-Down Buck Converter Module. Featuring a built-in LED digital voltmeter, this adjustable voltage regulator module lets you step down input voltage (4.5V–40V) to any output voltage between 1.25V and 37V — all with a simple potentiometer adjustment and one-touch button display switching. Whether you're powering a DIY electronics project, converting automotive voltages, or building a custom bench power supply, this module delivers stable, reliable performance.
Key Features
- Wide Input Range: Accepts 4.5V to 40V DC input
- Fully Adjustable Output: Output voltage continuously adjustable from 1.25V to 37V (input must be at least 1.5V higher than desired output)
- Built-in LED Digital Voltmeter: Onboard display shows input or output voltage with ±0.05V accuracy; toggle between readings with a single button press
- Self-Calibrating Voltmeter: Advanced microprocessor-based voltage measurement — calibrate once for accurate readings across the entire voltage range
- Settings Memory: All parameters and calibration settings are saved automatically, even after power cycling
- High Efficiency: Average conversion efficiency of ~88%, minimizing wasted energy
- Output Current: Up to 3A (recommended use within 2A); add heatsinking for sustained high-current applications
- Output Power: Up to 20W (add heatsinking for loads over 15W)
- Reverse Polarity Protection: Onboard protection prevents damage from accidental reversed connections
- Compact Form Factor: 66mm × 36mm × 14mm; weighs just 23g
Typical Applications
- DIY adjustable bench power supplies
- Automotive voltage conversion (e.g. 24V to 12V, 12V to 5V, 12V to 3.3V)
- Battery-powered project regulation
- Powering microcontrollers, sensors, and LED strips at custom voltages
- Industrial equipment voltage step-down (24V → 5V, 36V → 24V, etc.)
Technical Specifications
| IC | LM2596S ADJ |
| Input Voltage | 4.5V – 40V DC |
| Output Voltage | 1.25V – 37V DC (adjustable) |
| Max Output Current | 3A (2A recommended continuous) |
| Max Output Power | 20W (heatsink recommended above 15W) |
| Efficiency | ~88% average |
| Voltmeter Accuracy | ±0.05V |
| Voltmeter Range | 0 – 40V |
| Display Color | Blue LED |
| PCB Material | FR4 + Electronic Components |
| Dimensions | 66mm × 36mm × 14mm |
| Weight | 23g |
| Country of Origin | Made in China |
How to Use
- Adjust Output Voltage: Long-press the right button for 2 seconds, then release. The voltmeter and "OUT" indicator will flash together — you are now in output voltage adjustment mode. Use the left/right buttons to decrease or increase the voltage in fine increments.
- Monitor Input Voltage: When the display shows input voltage, long-press the right button to enter input voltage calibration mode ("IN" indicator flashes).
- Save Settings: Long-press the right button for 2 seconds to exit calibration mode. All settings save automatically and persist through power cycles.
Important Notes
- Input voltage must be at least 1.5V higher than the desired output voltage.
- If the output voltage cannot be adjusted and equals the input voltage, rotate the potentiometer counterclockwise 20+ turns to reset.
- For currents above 2A or power above 15W, add external heatsinking to prevent thermal issues.
- Ensure input voltage is 4.5V or above for accurate voltmeter readings.
Learn more: ENERGY STAR product efficiency guidance
Frequently Asked Questions
Q: What is the minimum input voltage for the LM2596 buck converter module to work correctly?
A: The LM2596 DC-DC step-down converter requires a minimum input voltage of 4.5V DC. Additionally, the input voltage must always be at least 1.5V higher than your desired output voltage. For example, to get a 5V output, you need at least 6.5V input. For best voltmeter accuracy, maintain at least 4.5V input.
Q: Can I use this LM2596 buck converter module in my car or vehicle?
A: Yes! This adjustable step-down power supply module is well-suited for automotive applications. It handles a 12V or 24V vehicle supply and can step it down to 5V, 3.3V, or any other voltage your accessories or electronics require — making it a versatile tool for in-vehicle DIY power projects.
Q: How do I switch the LED display between showing input and output voltage?
A: Simply press the button on the module to toggle the LED digital voltmeter between displaying the input voltage (indicated by the "IN" light) and the output voltage (indicated by the "OUT" light). The module saves your last display setting even after powering off and back on.
Q: Does this step-down converter protect against reverse polarity connection?
A: Yes. The LM2596 buck converter module includes onboard reverse polarity protection, so accidentally connecting your power source in reverse will not damage the module — a valuable safeguard during prototyping and DIY builds.
Production & Packaging Notice
To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.