LD24AJTA Mini LED Driver Module | ATMOSFÆR ENGINEERING

High-efficiency step-down LED driver module with adjustable constant current output (30-910mA, up to 1.2A). Features hysteretic control for simple design without compensation components. Supports both analog dimming and PWM dimming (5000:1 ratio) for precise brightness control. Ultra-compact size ideal for automotive lighting, LED retrofits, backlighting, and portable LED applications.

Technical Specifications:

• IC: LD24AJTA (Buck LED Driver)
• Input Voltage: 6V - 25V DC
• Output Current: 30mA - 910mA (adjustable via RCS resistor)
• Maximum Output Current: 1.2A (with proper heatsinking and modified RCS)
• Maximum Output Power: 22W @ 24V input
• Switching Frequency: Up to 1MHz
• Efficiency: Up to 97%
• Current Accuracy: ±5% (typical)
• Dimming Methods: PWM input or analog voltage control
• Dimming Ratio: 5000:1 (PWM)
• Control Type: Hysteretic (no compensation required)
• Current Sensing: High-side current sense
• Protection: Open-circuit LED protection (inherent)
• Module Dimensions: 18mm x 15mm x 6.5mm
• Weight: 2.1g
• Operating Temperature: -40°C to +85°C (typical)

Pin Configuration:

• VIN+: Positive input voltage (6-25V)
• GND: Ground
• LED+: LED positive output
• LED-: LED negative output
• DIM/EN: PWM dimming input / enable pin

Current Adjustment:

• Onboard potentiometer (RCS) for output current adjustment
• 30-910mA range (factory default)
• Up to 1.2A with resistor modification (requires heatsinking)

Dimming Control:

• PWM dimming: Apply PWM signal to DIM pin (5000:1 ratio)
• Analog dimming: Apply DC voltage to DIM pin
• Enable/disable: Pull DIM pin low to disable output

Features:

• Wide input voltage range (6-25V)
• Constant current regulation for stable LED brightness
• High efficiency reduces heat dissipation
• Ultra-compact PCB design
• Simple hysteretic control (no external compensation)
• Adjustable current via onboard potentiometer
• High dimming ratio (flicker-free at low brightness)
• Open LED protection prevents damage
• High-frequency operation for small inductor size

Applications:

• Automotive LED lighting (headlights, taillights, interior)
• 12V/24V LED strip and module driving
• Halogen bulb LED replacement
• Industrial machine lighting
• Architectural and accent lighting
• LED signs and displays
• LCD/TV backlighting
• Battery-powered LED systems (6V-24V)
• Solar-powered LED lighting
• SELV (Safety Extra-Low Voltage) lighting

LED Configuration Examples:

• 12V input → 3x 3W LEDs in series (9-12V forward voltage)
• 24V input → 7x 3W LEDs in series (21-24V forward voltage)
• Output voltage automatically adjusts to LED string requirements

Important Notes:

• Total LED forward voltage must be less than input voltage minus ~2V headroom
• Add heatsinking for continuous operation >500mA or high ambient temperatures
• Use quality electrolytic capacitors on input/output for stability
• PWM dimming frequency: 100Hz - 20kHz recommended
• For 1.2A operation, modify RCS resistor and ensure adequate cooling

Advantages:

• No complex compensation circuit required
• Very high efficiency (97%) reduces power waste
• Tiny footprint fits in tight spaces
• Works with any LED configuration (single or series)

Compatible with 12V/24V automotive systems, Arduino/ESP32 PWM control, and standard DC power supplies. Perfect for high-brightness LED projects requiring constant current regulation.