DollaTek Mini DC-DC Adjustable Step-Down Module User Manual

1. Introduction

This user manual provides detailed instructions for the DollaTek Mini DC-DC Adjustable Step-Down Module (Mini 360). This compact module is a non-isolated synchronous rectification BUCK converter designed to efficiently convert a higher DC input voltage to a lower, adjustable DC output voltage. Please read this manual thoroughly before use to ensure proper operation and safety.

2. Safety Instructions

Observe the following safety precautions to prevent damage to the module or connected devices, and to ensure personal safety:

• Ensure correct input and output polarity. Incorrect connections can damage the module and connected components.
• Do not exceed the maximum input voltage of 23V DC or the maximum output current of 3A (peak). Prolonged operation at maximum current is not recommended.
• Always verify the output voltage with a multimeter before connecting any load, especially sensitive electronics.
• Avoid short circuits on the output.
• Operate the module in a well-ventilated area to prevent overheating.
• Keep the module away from moisture and conductive materials.
• This module is intended for experienced users familiar with electronics and DC power circuits.

3. Product Overview

The DollaTek Mini 360 is a highly efficient step-down converter. Its small size makes it suitable for various embedded projects and applications requiring a regulated lower voltage from a higher source.

Figure 3.1: Overview of the DollaTek Mini 360 module with key components identified. This includes the adjustable potentiometer, input/output terminals, filter capacitors, and the buck converter chip.

Key components include:

• Adjustable Potentiometer: Used to set the desired output voltage.
• Input/Output Terminals: Clearly marked for DC input and regulated DC output.
• Synchronous Rectification Buck Chip: Provides efficient voltage conversion.
• Filter Capacitors and Inductor: Help to smooth the output voltage and reduce ripple.

4. Specifications

Figure 4.1: Physical dimensions of the DollaTek Mini 360 module.

5. Setup

Follow these steps to set up your DollaTek Mini 360 module:

1. Identify Terminals: Locate the input (IN+ / IN-) and output (OUT+ / OUT-) terminals on the module. Refer to Figure 5.1 for guidance.
2. Connect Input Power: Connect your DC power source (4.75V to 23V) to the IN+ (positive) and IN- (negative) terminals. Ensure correct polarity.
3. Initial Output Voltage Check: Before connecting any load, power on the module. Use a multimeter to measure the voltage across the OUT+ and OUT- terminals. The initial output voltage may vary.
4. Adjust Output Voltage: Carefully turn the small potentiometer (trimmer) on the module using a small screwdriver. Turning clockwise typically increases the voltage, while counter-clockwise decreases it. Adjust until the desired output voltage (between 1.0V and 17V) is achieved. Remember that the output voltage must always be lower than the input voltage.
5. Connect Load: Once the desired output voltage is stable and verified, connect your load to the OUT+ and OUT- terminals, observing correct polarity.

Figure 5.1: Connection diagram showing input (entrée) and output (sortie) terminals, voltage ranges, and the adjustable potentiometer (régler la tension de sortie).

6. Operating Instructions

Once the module is set up and the output voltage is adjusted, it will provide a stable DC voltage to your connected load. Monitor the module's temperature during operation, especially when drawing higher currents. If the module becomes excessively hot, reduce the load or improve ventilation.

• The module is designed for continuous operation within its rated current of 1.8A. Brief peaks up to 3A are permissible but not recommended for sustained periods.
• The output voltage will remain stable as long as the input voltage is within the specified range and the load current does not exceed the module's capabilities.

7. Maintenance

The DollaTek Mini 360 module requires minimal maintenance. Keep the module clean and free from dust and debris. Ensure that the connections remain secure. No user-serviceable parts are inside the module. Do not attempt to disassemble or modify the module, as this will void any potential warranty and may cause damage.

8. Troubleshooting

If you encounter issues with your DollaTek Mini 360 module, consider the following troubleshooting steps:

• No Output Voltage:
  • Check if the input power source is connected correctly and providing voltage within the 4.75V-23V range.
  • Verify input and output polarity.
  • Ensure the potentiometer is not turned to its minimum setting (0V output is possible). Try adjusting it.
• Incorrect Output Voltage:
  • Use a multimeter to accurately measure the output voltage.
  • Adjust the potentiometer carefully to achieve the desired voltage.
  • Ensure the input voltage is stable and within the specified range.
  • Remember that output voltage must always be less than input voltage.
• Module Overheating:
  • Reduce the load current. The module may be drawing more than its rated 1.8A.
  • Ensure adequate ventilation around the module.
  • Verify that the input voltage is not excessively high for the required output voltage, which can increase power dissipation.
• Output Voltage Fluctuates:
  • Check for loose connections at both input and output terminals.
  • Ensure the input power source is stable and free from significant voltage fluctuations.
  • The load might be drawing current intermittently or exceeding the module's capacity.

9. Warranty and Support

Specific warranty information for the DollaTek Mini DC-DC Adjustable Step-Down Module is not provided in the product details. For any support inquiries, technical assistance, or warranty claims, please contact the seller or retailer from whom you purchased the product. Ensure you retain your proof of purchase.