3.3V/1A DC-DC Power Supply (H03R0x)


3.3V / 1A DC-DC Buck Power Supply With Terminal Block or DC Jack Input

Stage: Production


H03R0x is a compact DC-DC buck power supply with a 3.3V/1A DC output and 5-40V DC input. The output voltage is provided through Hexabitz SMD edge-pad connectors (3.3V on top and GND on bottom). The -T module version comes with a 5.08 mm terminal block connector for input voltage, while the -J comes with a DC power jack. Use this module to power all your Hexabitz creations (and other hardware) from a DC source (battery, AC/DC wall adapter, etc.)


Technical Specifications

  • Input voltage: +5V to +40V DC.
  • Output voltage: +3.3V DC.
  • Output current: 1A.
  • Six output power ports (+3.3V and GND).
  • TI LM2575SX-3.3/NOPB high-efficiency, 1A, step-down, switching voltage regulator:
    • 52 kHz Fixed Frequency Internal Oscillators.
    • Thermal shutdown and current limit protection.
  • Green power-OK LED.
  • Input voltage connector: TE Connectivity/AMP 2-position 5.08 mm shrouded vertical or right-angle terminal block or CUI PJ-202A horizontal DC power jack.

Physical Properties

  • Shape: Hexagon
  • Size: 30 mm short diagonal
  • Area: 7.8 cm^2
  • Weight: 4 g
  • Soldermask Color: Dark green
  • Finish: ENIG (gold) or HASL-LF (tin)


Please visit this product projects on Hackster.io network.


H03R00-T BOM

Quickstart Guide

Download a PDF version here.


Frequently Asked Questions

A: Depends on type of modules connected, but usually 40+ modules can be powered from a single H03R00.

A: You can solder wires and many types of connectors to the SMD edge pads. Our favorite one is the 2-pin 2.54 mm male header which fits their perfectly, but many other connectors work fine as well.

A: Theoretically you can do that as the edge PCB connectors are perfect to connect modules in parallel.  However, be careful, as sometimes small variations in output voltage might cause current to flow from one power supply to another. We will have in the future dedicated modules to handle load-sharing between power supplies!

Have more questions? Please check our main FAQ page and feel free to contact us for any unanswered questions.


Download a PDF version here.


  • Schematics (PDF)
  • Hardware Design Files (Circuit Maker, EAGLE)
  • Documentation / Factsheet (PDF)
  • Projects & Examples: Please check our account on Hackster.io for demo projects and examples.