PCA9685 16-Channel 12-Bit PWM I2C LED Driver Module | ATMOSFÆR ENGINEERING

Professional 16-channel PWM controller with I2C interface for precise LED brightness control and servo motor driving. Features 12-bit resolution (4096 levels) for smooth, flicker-free dimming and programmable frequency up to 1526Hz. Ideal for RGB/RGBA LED strips, multi-servo robotics, and complex lighting projects requiring independent channel control with minimal GPIO usage.

Technical Specifications:

• IC: PCA9685 (NXP/TI)
• Interface: I2C (TWI)
• Channels: 16 independent PWM outputs
• Resolution: 12-bit (4096 brightness levels)
• PWM Frequency Range: 24Hz - 1526Hz (programmable)
• Duty Cycle: 0% - 100% (independent per channel)
• Operating Voltage: 2.3V - 5.5V (logic and power)
• I/O Voltage Tolerance: 5.5V max
• Output Current: 25mA sink (typical @ 5V), 10mA source
• I2C Address: 0x40 (default), configurable via solder jumpers (up to 62 devices on one bus)
• Clock Source: Internal oscillator or external clock input (up to 50MHz)
• Standby Current: Low power consumption
• Built-in Features: Power-on reset, output enable pin
• PCB Dimensions: 62mm x 29mm
• Operating Temperature: -40°C to +85°C (typical)

Pin Configuration:

• VCC: Power supply (2.3V - 5.5V)
• GND: Ground
• SDA: I2C data line
• SCL: I2C clock line
• OE: Output enable (active low, optional)
• EXTCLK: External clock input (optional)
• V+: LED power supply (separate from logic, up to 6V typical)
• PWM0-PWM15: 16 independent PWM outputs

Address Configuration:

• Default I2C address: 0x40
• Configurable via 6 solder jumper pads (A0-A5)
• Allows up to 62 PCA9685 modules on single I2C bus

Features:

• 16 independent PWM channels with individual control
• High-resolution 12-bit PWM (smoother than 8-bit Arduino PWM)
• Programmable frequency for flicker-free LED control
• All channels share same frequency but independent duty cycles
• External clock synchronization for multi-board sync
• Directly drive LEDs up to 25mA per channel
• Can control servos (typical 50Hz operation)
• Minimal microcontroller load (I2C control only)
• Onboard oscillator (no external components needed)
• Staggered output switching reduces EMI

Included in Package:

• 1x PCA9685 PWM driver module
• 1x 15-pin straight header (for terminal connections)
• 1x 5-pin angled header (for I2C interface)

Applications:

• RGB/RGBA LED strip control (independent color channels)
• Multi-servo robotics (up to 16 servos from 2 GPIO pins)
• Architectural and stage lighting
• LED matrix driving
• PWM motor speed control (low-current motors)
• LCD backlight brightness control
• Custom LED animations and effects
• Multi-channel dimming systems
• Ambient lighting controllers

Typical Use Cases:

• RGB Lighting: Control 5+ RGB LED strips independently (3 channels per strip)
• Servo Control: Drive 16 servos simultaneously for robot arms, hexapods
• LED Effects: Create complex animations without blocking code execution
• Backlight Dimming: Smooth LCD/monitor backlight control

Connection Example (RGB LED Strip):

• VCC, GND, SDA, SCL → Microcontroller
• V+ → LED power supply (12V/24V)
• PWM0 → Red channel (via MOSFET for high-power strips)
• PWM1 → Green channel
• PWM2 → Blue channel

Servo Control:

• Set frequency to 50Hz (typical servo requirement)
• Connect servo signal wires to PWM outputs
• Power servos from V+ terminal (4.8V-6V typical)

Important Notes:

• For LEDs >25mA, use external MOSFETs (IRLZ44N recommended)
• Separate power supply recommended for high-current LED loads
• All 16 channels share the same PWM frequency (individually set duty cycle only)
• For servo control, use 50-60Hz frequency setting
• Pull-up resistors required on SDA/SCL (often built into microcontroller boards)
• Total current draw limited by power supply and PCB traces

Advantages over Arduino PWM:

• 16 channels vs 6 PWM pins (Arduino Uno)
• 12-bit (4096 levels) vs 8-bit (256 levels)
• Frees up microcontroller pins
• Hardware-based (no software timing required)

Compatible with Arduino, ESP32, Raspberry Pi, STM32, and any microcontroller with I2C support. Libraries available for Arduino IDE (Adafruit_PWMServoDriver) and Python (for Raspberry Pi).