SparkFun Buck Regulator Breakout - 1.8V (AP3429A)

The SparkFun 1.8V Buck Regulator Breakout features the AP3429A from Diodes Inc., a 2A step-down DC-DC converter with an input voltage range of 2.7V to 5.5V. This full-size, 1in. x 1in. version of our buck regulator boards is configured to provide a regulated 1.8V output, which is controlled by an EN (enable) pin. To dissipate excess heat, a 0.6in. x 0.5in. copper pad is provided to attach a heat sink to the bottom of the board.

As a full-size buck regulator breakout, additional options for connecting input and output power are available. There is a pre-assembled screw terminal for a non-permanent connection, the option to solder on a barrel jack for an external power supply, and five PTH pins to create a more permanent installation. Our full-size buck regulators also come with a red, power indication LED that light up when the power output is enabled. This board has four mounting holes compatible with 4-40 hardware.

Buck Board:

  • 1in. x 1in. PCB layout
  • Three power input/output options:
    • Pre-assembled 4-pin screw terminal
    • Five 0.1in. spaced PTH pins
    • Four plated slots for a DC barrel jack (input only)
  • Power connections:
    • VIN - Power In (2.7V to 5.5V)
    • GND - Common Ground
    • VOUT - Power Out (Regulated 1.8V)
    • EN - Enable (Pull high to enable the power output)
  • Red, power LED indicator
  • 0.5in. x 0.6in. Plated copper pad (for heat sinks)


  • VIN: 2.7V to 5.5V
  • VOUT: 0.6V to VIN
  • 2A Continuous Output Current
  • 90µA No-Load Quiescent Current
  • 1MHz Switching Frequency
  • Protection Circuitry
    • Undervoltage Lockout (UVLO)
    • Input Overvoltage Protection
    • Over Current Protection
      • Cycle-by-Cycle Peak Current Limit
    • Thermal Shutdown (160°C/320°F)

SparkFun Buck Regulator Breakout - 1.8V (AP3429A) Product Help and Resources

Core Skill: Soldering

This skill defines how difficult the soldering is on a particular product. It might be a couple simple solder joints, or require special reflow tools.

1 Soldering

Skill Level: Noob - Some basic soldering is required, but it is limited to a just a few pins, basic through-hole soldering, and couple (if any) polarized components. A basic soldering iron is all you should need.
See all skill levels

Core Skill: DIY

Whether it's for assembling a kit, hacking an enclosure, or creating your own parts; the DIY skill is all about knowing how to use tools and the techniques associated with them.


Skill Level: Noob - Basic assembly is required. You may need to provide your own basic tools like a screwdriver, hammer or scissors. Power tools or custom parts are not required. Instructions will be included and easy to follow. Sewing may be required, but only with included patterns.
See all skill levels

Core Skill: Programming

If a board needs code or communicates somehow, you're going to need to know how to program or interface with it. The programming skill is all about communication and code.

2 Programming

Skill Level: Rookie - You will need a better fundamental understand of what code is, and how it works. You will be using beginner-level software and development tools like Arduino. You will be dealing directly with code, but numerous examples and libraries are available. Sensors or shields will communicate with serial or TTL.
See all skill levels

Core Skill: Electrical Prototyping

If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.

3 Electrical Prototyping

Skill Level: Competent - You will be required to reference a datasheet or schematic to know how to use a component. Your knowledge of a datasheet will only require basic features like power requirements, pinouts, or communications type. Also, you may need a power supply that?s greater than 12V or more than 1A worth of current.
See all skill levels


Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

Customer Reviews

No reviews yet.