XL4015 5A Adjustable Step-Down Buck Converter - Constant Current/Voltage Module

Specifications

• Input Voltage Range: 4V to 38V DC

• Output Voltage Range: 1.25V to 36V DC (Continuously Adjustable)

• Maximum Output Current: 5A (Heatsink recommended for >3A)

• Regulation Modes: Constant Current (CC) and Constant Voltage (CV)

• Conversion Efficiency: Up to 96%

• Switching Frequency: 180KHz

• Status Indicators: Red (CC Mode), Blue (Charging), Green (Full Charge/Idle)

• Terminals: Screw-type "IN+"/"IN-" and "OUT+"/"OUT-" for secure wiring

Key Applications & Projects

• Lithium Battery Charger: Safely manage the CC and CV stages for DIY battery packs.

• High-Power LED Driver: Drive 10W–50W LED arrays with stable, regulated current.

• Bench Power Supply: Create a portable, high-current, adjustable lab supply.

• Vehicle Power Systems: Convert 24V truck power to stable 12V or 5V for auxiliary equipment.

Unlock New Capabilities (Project Evolution)

• Feature Upgrade: The addition of the Current Adjustment pot allows this module to function as a safety limiter, preventing connected circuits from drawing too much power and burning out.

• Effort Level: Intermediate. Requires a multimeter and basic knowledge of CC/CV charging principles to calibrate properly.

Virtual Technician & Tips

• Probots™ Logic-Safe Setup: When using this for battery charging, adjust the output voltage to the battery's "float" voltage first, then short the output with an ammeter to set the maximum charge current using the CC pot.

• Pro Tip: Clockwise rotation increases both voltage and current limits. If drawing more than 3A continuously, add an adhesive aluminum heatsink to the XL4015 chip to prevent thermal throttling.

PACKAGE INCLUDED

• 1 x XL4015 Step-Down Buck Converter Module

FREQUENTLY ASKED QUESTIONS (FAQ)

• What is the maximum input voltage? The module supports up to 38V DC input.
• Can I use this to step up voltage? No, this is a "buck" or step-down converter; the output must always be lower than the input.
• How do I adjust the current limit? Turn the "Current Adjustment" potentiometer (W103) clockwise to increase the limit.
• What do the three LEDs mean? Red indicates Constant Current mode, Blue means the battery is charging, and Green indicates the battery is full or the output is idle.
• Is it safe to charge a 3.7V Li-ion battery? Yes, but you must precisely set the CV to 4.2V and the CC to the battery's rated charge current before connecting it.
• Does it have reverse polarity protection? No, connecting the input backward will damage the module instantly.
• What is the minimum input voltage? The input must be at least 4V.
• Can it drive 5A continuously? For continuous 5A draw, active cooling or a significant heatsink is required. 2A-3A is recommended for passive cooling.
• What is the lowest output voltage? It can be adjusted as low as 1.25V.
• Does it include the mounting screws? No, the board features standard mounting holes for M3 standoffs (sold separately).
• Can I use this as an LED driver? Yes, it is ideal for LEDs because of its Constant Current (CC) mode.
• What is the switching frequency? It operates at a high frequency of 180KHz for efficiency.
• Are the terminals marked? Yes, the board is clearly labeled for "IN+", "IN-", "OUT+", and "OUT-".
• What is the conversion efficiency? It can reach up to 96% depending on the voltage drop and current.
• Does the output voltage change if the input voltage fluctuates? No, the module regulates the output to your set voltage regardless of input variations (as long as input > output).
• How do I know if it’s in Constant Current mode? The Red LED will turn on when the connected load reaches your set current limit.
• Can I use this with a solar panel? Yes, provided the panel's open-circuit voltage does not exceed 38V.
• Is the output isolated from the input? No, it is a non-isolated buck converter; they share a common ground.
• What size are the onboard capacitors? The module typically uses 220uF 50V aluminum electrolytic capacitors.
• Is the adjustment screw multi-turn? Yes, the precision potentiometers require multiple turns for fine-grained control.