20A 300w DC-DC Buck Converter

Product Parameters

Module Features:
Synchronous rectification, non-isolated step-down constant current and constant voltage CC CV charging module.

Application Scope:
High-power LED constant current drive, lithium battery charging (including iron-lithium battery), 4V, 6V, 12V, 14V, 24V lead-acid battery charging, nickel-cadmium/nickel-metal hydride batteries (battery packs) charging, solar panels, wind turbines.

Input Voltage: 6–40VDC

Output Voltage: Continuously adjustable (1.2–35VDC), long-term use below 32V (for input voltage higher than output voltage applications, cannot boost).

Output Current: Maximum 20A for short time, within 15A for long time (when power tube temperature exceeds 65°C, need fan cooling; reduce load when outputting high current for long periods).

Current Limiting Range: 0.2–20A (adjustable). When module exceeds 65°C, fan cooling is required.

Minimum Voltage Drop: 3V

Operating Frequency: 150KHz

Conversion Efficiency: Typical value 96% (related to pressure difference and usage environment).

Output Ripple: Around 50mV (excluding noise) at 20MHz bandwidth (for reference only, tested at input 24V).

Operating Temperature: 0°C to +75°C (during actual use, pay attention to the power tube temperature; strengthen heat dissipation or reduce load if temperature is too high).

Output Adjustment Method:

• CV potentiometer: clockwise (increase), counterclockwise (decrease)
• CC potentiometer: clockwise (increase), counterclockwise (decrease)

Output Short Circuit Protection: Yes (instant short circuit protection, constant current; if set current value is not suitable for long-term short circuit).

Input Reverse Connection Protection: None

Output Anti-backflow: None. For loads with their own power or inductive loads, external diode is needed!

Wiring Method: Terminal connection

How to Adjust Output Current:

1. Adjust CV potentiometer: According to your load requirement, set the output voltage to the desired level.

2. Counterclockwise rotate CC potentiometer about 30 turns (this means output current is set to minimum). Connect LED, adjust CC potentiometer to the current required by your load. For battery charging, after battery is fully discharged, adjust CC potentiometer to the charging current you need. (Recommended charging current = 0.1–0.3 times battery capacity, e.g., for a 20Ah battery, set charging current to 2–6A). 

For charging batteries, after fully discharging the battery, connect it to the output, then adjust the CC potentiometer to the required charging current.

(Note: For battery charging, the battery must be fully discharged before adjustment, because the closer the battery is to being fully charged, the smaller the charging current will be.

Board Diagram Labels (top to bottom, left to right):

Indicator light

Input negative (IN–)

Input positive (IN+)

Output positive (OUT+)

Output negative (OUT–)

CV: Voltage adjustment potentiometer (W104)

CC: Current adjustment potentiometer (W104)

Product Size:

Length: 53 mm