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The SY81103 DC-DC Buck Converter is a compact, high-efficiency power conversion module designed to reduce a higher input voltage to a stable lower output voltage. Built around the SY81103 synchronous step-down IC, it ensures minimal power loss and high performance, making it ideal for battery-powered and industrial applications.

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Product Variants

To accommodate different system requirements, this module is available in three distinct variants:
  1. Fixed 3.3V Output: Pre-configured to provide a steady 3.3V DC output.
  2. Fixed 5V Output: Pre-configured to provide a steady 5V DC output.
  3. Variable Output: Features an adjustable output range from 1.2V to 5V using an onboard potentiometer.

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Key Features

  • SY81103 High-Efficiency IC: Synchronous rectification technology for cool operation.
  • Wide Input Range: Supports input voltages from 9V to 18V.
  • High Load Capacity: Delivers up to 3A output current.
  • Stable 500kHz Frequency: Ensures low ripple and high efficiency.
  • Protection: Includes cycle-by-cycle current limit and thermal shutdown.
  • Compact G-Mod Footprint: Designed to fit seamlessly onto Glyph development boards.

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Technical Specifications

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Pin Configuration

The module features input and output terminal blocks for easy integration: Left Side – INPUT
  • VIN (+) → DC Input Supply (9V – 18V)
  • GND (–) → DC Input Ground
Right Side – OUTPUT
  • VOUT (+) → Regulated DC Output (3.3V / 5V / 1.2V–5V)
  • GND (–) → Output Ground

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Applications

  • IoT & Sensors: Powers microcontrollers and sensors from 12V batteries.
  • Industrial Automation: Provides stable control-line power in noisy environments.
  • Automotive Electronics: Regulates 12V vehicle power for sensitive electronics.
  • Battery Management: Efficiently steps down Li-ion battery pack voltages (3S/4S).
  • Prototyping: Ideal for breadboard and custom PCB power distribution.
Please ensure you choose the correct variant (Fixed or Variable) based on your specific application needs.

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Step 1: Hardware Required

  1. SY81103 DC–DC Buck Converter Module (Variant-specific)
  2. DC Power Supply (9V – 18V)
  3. Multimeter (for Variable variant calibration)
  4. Jumper Wires / Connecting Wires

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Step 2: Circuit Connection

Connect the input source to the input terminals. For the variable variant, it is recommended to adjust the potentiometer before connecting your final load.
Ensure the input polarity is correct before powering the module. Reverse polarity can permanently damage the SY81103 IC.
DC-DC CONVERTER DIAGRAM

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Step 3: Observe the Output

  1. Verify Input: Use a multimeter to confirm your input voltage is within the 9V–18V range.
  2. Set Output (Variable Variant Only): Rotate the onboard potentiometer until the desired voltage (e.g., 3.3V or 5V) is reached.
  3. Confirm Stability: Check that the output remains stable even when the load is connected.
  4. Thermal Check: The module is designed for low heat generation, but ensure adequate airflow if drawing the full 3A current for extended periods.