The SparkFun 1.8V Buck Regulator Breakout features the AP3429A step-down DC-DC converter, providing a regulated 1.8V output at up to 2A continuous current from a 2.7V to 5.5V input. An enable pin allows the output to be switched on and off programmatically.

The 1" × 1" board offers multiple power connection options: a pre-assembled screw terminal, PTH pins for permanent installation, and plated slots for a DC barrel jack input. A red LED indicates when power output is enabled, and a copper pad on the bottom accommodates a heat sink.

Key Features

• 1.8V Regulated Output – 2A continuous from the AP3429A
• Enable Pin – Software-controlled output switching
• Multiple Input Options – Screw terminal, PTH pins, or barrel jack
• Power LED – Red indicator when output is active
• Heat Sink Pad – 0.5" × 0.6" copper pad on bottom
• Mounting Holes – 4× 4-40 compatible

Specifications

• IC – AP3429A (Diodes Inc.)
• Input Voltage – 2.7V to 5.5V
• Output Voltage – 1.8V regulated
• Output Current – 2A continuous
• Quiescent Current – 90µA (no load)
• Switching Frequency – 1MHz
• Protection – UVLO, input overvoltage, cycle-by-cycle current limit, thermal shutdown (160°C)
• Board Size – 1" × 1" (25.4 × 25.4mm)

Pin Connections

• VIN – Power input (2.7–5.5V)
• GND – Common ground
• VOUT – Regulated 1.8V output
• EN – Enable (pull high to enable output)

Resources

• Hookup Guide
• Schematic (PDF)
• AP3429A Datasheet (PDF)
• GitHub Hardware Repo