HLK-PM03 AC-DC Modular Power Supply 240V - 3.3V 3W 0.9A PCB Mount Converter

Product description: HLK-PM03 AC-DC Modular Power Supply 240V - 3.3V 3W 0.9A

HLK-PM03 is a miniature power supply that accepts 100-240V AC input and delivers stable 3.3V DC with an output current capability of 0.9A. This compact module occupies far less space on PCBs than traditional PCB-mount transformers. This version is intended for direct soldering onto the printed circuit board. It works excellently as a power source in a wide range of electronic applications, including ESP8266, ESP32, Arduino, and Raspberry Pi.

Module connections

1. AC - power input: 100-240V AC
2. + Vo - DC output - PLUS
3. - Vo - DC output - MINUS

Key technical specifications

• Input voltage: 100 - 240V AC
• Output voltage: 3.3V DC
• Maximum output current: 900mA
• Efficiency at 220V AC input: 70%
• External dimensions: 34 mm x 20.2 mm x 15 mm
• Permissible ambient temperature: -20°C to 60°C
• Permissible ambient humidity: 5-95%
• Protection: short-circuit, thermal, overcurrent

Example applications

• Powering IoT circuits based on microcontrollers requiring 3.3V (ESP8266, ESP32)
• Compact Smart Home devices installed in flush-mounted wall boxes
• Powering communication modules and sensors in building automation systems
• DIY projects and electronic device prototypes (Arduino, Raspberry Pi)
• Replacing traditional, bulky transformers in PCB power supply circuits

Benefits

• Space saving: Very small dimensions enable miniaturization of designed devices
• Easy mounting: Pins designed for direct soldering to the printed circuit board
• Circuit safety: Built-in short-circuit, thermal, and overcurrent protection safeguards powered components
• Versatile power input: Wide input voltage range (100-240V AC) allows operation on power grids worldwide
• High reliability: Stable 3.3V DC output ideal for sensitive digital electronics