If you’ve ever worked with LED strips—especially RGB or addressable LEDs—you may have come across the terms “common anode” and “common cathode.” While they might sound technical, understanding their differences is crucial for proper wiring, controller compatibility, and avoiding frustration in your lighting projects.
In this guide, we’ll break down:
✔ What common anode and common cathode LED strips are
✔ How they work differently
✔ Key differences and when to use each
✔ Common mistakes to avoid
In this guide, we’ll break down:
✔ What common anode and common cathode LED strips are
✔ How they work differently
✔ Key differences and when to use each
✔ Common mistakes to avoid
1. What Are Common Anode and Common Cathode LED Strips?
Both terms refer to how the LEDs in a strip are wired internally. The main difference lies in which LED terminal (anode or cathode) is shared across all LEDs.
Common Anode LED Strips:
Definition: All LEDs share a common positive (anode) connection.
How it works:
The anode (+) is connected directly to the power supply.
Each LED’s cathode (-) is controlled individually (usually via a PWM signal).
The LED turns ON when the cathode is pulled LOW (0V/GND).
Common Cathode LED Strips:
Definition: All LEDs share a common negative (cathode) connection.
How it works:
The cathode (-) is connected directly to ground (GND).
Each LED’s anode (+) is controlled individually.
The LED turns ON when the anode is driven HIGH (e.g., +5V or +12V).
2. Key Differences Between Common Anode and Common Cathode
| Feature | Common Anode | Common Cathode |
|---|---|---|
| Shared Terminal | Anode (+) | Cathode (-) |
| Control Signal | Low (0V) turns LED ON | High (e.g., +5V) turns LED ON |
| Compatibility | Works with low-side drivers (sinking current) | Works with high-side drivers (sourcing current) |
| Noise Immunity | Better (less susceptible to voltage fluctuations) | Slightly worse (requires stable high signal) |
| Common Uses | Older RGB strips, industrial applications | Modern RGB strips, Arduino/Raspberry Pi projects |
3. Which One Should You Choose?
When to Use Common Anode
✅ You have a low-side driver (e.g., some LED controllers sink current).
✅ Your project requires better noise immunity (e.g., long wire runs).
✅ You’re working with older RGB LED strips.
When to Use Common Cathode
✅ You’re using modern microcontrollers (Arduino, ESP32, Raspberry Pi).
✅ You need PWM dimming (most MCUs output high-side signals).
✅ You’re working with newer RGB or addressable LED strips.
4. Common Mistakes to Avoid
⚠ Mixing up anode/cathode wiring → LEDs won’t light up or may burn out.
⚠ Using the wrong controller → Common anode strips need low-side drivers, while common cathode strips need high-side drivers.
⚠ Ignoring voltage levels → Ensure your power supply matches the LED strip’s requirements (e.g., 5V, 12V, 24V).
5. Conclusion
Understanding common anode vs. common cathode LED strips helps you choose the right type for your project and avoid wiring mistakes.
Common anode = Shared (+) terminal, controlled by pulling cathodes LOW.
Common cathode = Shared (-) terminal, controlled by driving anodes HIGH.
Most modern LED projects use common cathode due to better compatibility with microcontrollers, but common anode still has its place in industrial or noise-sensitive applications.
