The AP3429A Buck Converter Breakout steps down 3.4–5.5V input to a stable 3.3V output at up to 1.2A, with 90–95% efficiency. It's ideal for powering 3.3V circuits from LiPo batteries, 3× alkaline cells, or USB power sources.

Designed to be pin-compatible with the LM1117-3.3V TO-220 regulator, you can swap it in for significantly better efficiency. An enable pin lets you shut down the output completely by pulling it low. Comes fully assembled and tested with header included for breadboard use.

Key Features

• 3.3V Regulated Output – Up to 1.2A load current
• Wide Input Range – 3.4V to 5.5V (LiPo, 3× alkaline, USB)
• High Efficiency – 90–95% typical efficiency
• 1MHz Fixed Frequency – Compact inductor and low noise
• Enable Pin – Tie low to shut down output completely
• LM1117-3.3V Pin Compatible – Drop-in replacement for TO-220 regulators
• Breadboard Ready – Header included for easy prototyping

Specifications

• IC: AP3429A
• Input Voltage: 3.4–5.5V
• Output Voltage: 3.3V
• Max Output Current: 1.2A
• Switching Frequency: 1MHz
• Efficiency: 90–95%

Ideal For

• Portable projects powered by LiPo or alkaline batteries
• USB-powered 3.3V circuits
• Replacing inefficient linear regulators like the LM1117

Package Contents

• 1× AP3429A 3.3V buck converter breakout (assembled and tested)
• 1× Header strip

Need a wider input range? Check out the MPM3610 3.3V Buck Converter Breakout with up to 21V input.