PLCC-4 / 3528 SMD
PLCC-4 / 3528 SMD LEDs are 4-pin surface-mount LEDs that share the same 3.5mm × 2.8mm physical body as the single-color PLCC-2 / 3528, but with four leads instead of two. Those extra pins enable RGB (red-green-blue) color mixing: three independent LED dies — one red, one green, one blue — share a common cathode inside a single 3528 housing. By varying the current to each die via PWM (pulse-width modulation) from a microcontroller, you can produce any visible color from a single component. The PLCC-4 / 3528 RGB LED is the standard emitter used in addressable and non-addressable 3528-type LED strips, custom lighting controllers, and compact RGB indicator circuits. We stock PLCC-4 LEDs in common-cathode RGB configuration.
Custom RGB lighting projects are the primary use case for PLCC-4 / 3528 LEDs. Hobbyists building custom ambient lighting for PC cases, home theater accent lighting, under-cabinet color-changing strips, and cosplay costume effects use these LEDs either as individual components on custom PCBs or as replacements for failed emitters on existing 3528 LED strip segments. Arduino, ESP32, ESP8266, and Raspberry Pi Pico projects commonly drive PLCC-4 RGB LEDs through MOSFET transistors or dedicated LED driver ICs (like the TLC5940 or PCA9685) for smooth PWM dimming across all three channels. The r/arduino, r/esp32, r/FastLED, and r/homeassistant communities share PCB designs and firmware for driving RGB LEDs in home automation setups. For individual-pixel addressable RGB (where each LED has its own controller IC), the PLCC-6 / 5050 package is more common; the PLCC-4 / 3528 is preferred when you want a smaller form factor and are willing to run all LEDs on the same color channel or multiplex them with external circuitry.
Automotive accent lighting and gauge cluster color changes provide another strong demand signal for PLCC-4 / 3528 RGB LEDs. Car enthusiasts who want to change the color of their instrument cluster backlighting — say, converting a factory amber/orange cluster to blue, red, or any custom color — can replace the single-color PLCC-2 LEDs on the cluster PCB with PLCC-4 RGB LEDs, then wire the three color channels to a small microcontroller or rotary-encoder color selector hidden behind the dash. This gives full user-selectable gauge backlighting color. The GM Truck, Honda-Tech, and Nissan/Infiniti forums have build threads documenting this modification. Footwell accent lighting, door panel backlighting, and center console illumination projects also use PLCC-4 LEDs soldered to custom PCBs cut to fit specific vehicle trim panels.
Soldering PLCC-4 LEDs by hand is slightly more involved than the 2-pin PLCC-2 because you have four pads instead of two, and the pads are closely spaced on the shorter sides of the 3528 body. However, the process is very manageable with a fine-tip soldering iron (conical or thin chisel), flux, and standard 0.5mm solder wire. The technique: apply flux to all four PCB pads, position the LED with tweezers (checking the cathode/polarity indicator against the PCB silkscreen), tack one corner pin, verify alignment, then solder the remaining three pins in sequence. If a solder bridge forms between adjacent pins on the same side, drag-soldering with flux or touching the bridge with clean solder wick resolves it easily. For desoldering, a hot-air station at 300–350°C is the cleanest method — it heats all four joints simultaneously and lifts the part without stressing individual pads. For production assembly, PLCC-4 LEDs reflow solder with standard profiles and are compatible with pick-and-place machines.
Electrical specifications: each die inside the PLCC-4 / 3528 RGB LED has its own forward voltage. Red ≈ 1.8–2.2Vf; green ≈ 2.8–3.4Vf; blue ≈ 2.8–3.4Vf. Maximum forward current is typically 20mA per die (60mA total when all three channels are on simultaneously at full brightness). Each color channel needs its own current-limiting resistor because the forward voltages differ — a single shared resistor would cause uneven brightness and color shift. For a 5V supply driving all three channels at 20mA: red resistor ≈ 150Ω, green resistor ≈ 100Ω, blue resistor ≈ 100Ω. Our LED resistor calculator computes values for any voltage and current combination. When driving from a microcontroller GPIO pin (typically 3.3V), reduce the resistor values accordingly and stay within the GPIO current limit (usually 12–20mA per pin on an ESP32 or Arduino). For higher LED currents, use MOSFET transistors (IRLZ44N or similar logic-level FETs) switched by the microcontroller PWM output.
RGB color mixing basics: the three dies (red, green, blue) combine additively to produce any color in the visible spectrum. Red + green = yellow. Red + blue = magenta/purple. Green + blue = cyan. All three at equal brightness = white (the shade of white depends on the die intensities and is rarely a perfect neutral; some tuning via PWM duty cycle is usually needed). PWM frequency should be at least 200Hz to avoid visible flicker — most microcontroller PWM libraries default to 1kHz or higher. For smooth color transitions and animations, the FastLED library (Arduino/ESP32) and the NeoPixel library (though NeoPixel is designed for addressable LEDs, the PWM color-mixing math applies to any RGB LED) provide convenient HSV-to-RGB conversion functions. If you want per-pixel addressable control without external multiplexing, consider upgrading to PLCC-6 / 5050 RGB LEDs paired with a WS2812B or SK6812 controller IC, or to our through-hole RGB LEDs for breadboard prototyping.
Choosing between PLCC-4 and adjacent packages: if you need a single-color LED in the same 3528 form factor, the 2-pin PLCC-2 / 3528 is simpler and cheaper. If you need higher per-channel output and independent anode/cathode pairs for each die, the 6-pin PLCC-6 / 5050 (5.0mm × 5.0mm) is the step up. For chip-type SMD LEDs in single colors, see 0805 or 1206. For through-hole RGB prototyping, see our RGB LEDs category. The SMD LEDs parent category lists all surface-mount packages we carry.