SMD RGB LED with Embedded IC - Constant Current Control - 5V - 65mA - White Diffused Lens - English Technical Datasheet

1. Product Overview

This document details the specifications for a surface-mount RGB LED component that integrates a control circuit and RGB chips within a single package. This integrated design forms a complete, individually addressable pixel point, eliminating the need for external driver circuitry for constant current operation. The device is engineered for automated PCB assembly and is suitable for space-constrained applications across a broad spectrum of electronic equipment.

1.1 Core Advantages and Target Market

The primary advantage of this component is its all-in-one design. By embedding an 8-bit driver IC, it provides constant current PWM control for each of the red, green, and blue chips. This allows each primary color to achieve 256 levels of brightness, enabling the creation of over 16.7 million distinct colors. Signal transmission between multiple units is simplified through a single-wire cascading port. Key features include RoHS compliance, packaging compatible with automatic placement equipment, and suitability for infrared reflow soldering processes. Its target applications span telecommunications, office automation, home appliances, industrial equipment, status indicators, front panel backlighting, full-color modules, decorative lighting, and indoor video displays.

2. Technical Parameters: In-Depth Objective Interpretation

2.1 Absolute Maximum Ratings

Operating the device beyond these limits may cause permanent damage. The absolute maximum ratings are specified at an ambient temperature (Ta) of 25°C.

• Power Dissipation (P): 358 mW. This is the maximum total power the package can dissipate.
• Supply Voltage Range (VDD): +4.2V to +5.5V. The embedded IC requires this regulated voltage range for proper operation.
• Total DC Forward Current (IF): 65 mA. This is the maximum total current that can be supplied to the combined RGB chips.
• Operating Temperature Range: -40°C to +85°C.
• Storage Temperature Range: -40°C to +100°C.

2.2 Optical Characteristics

Optical performance is measured at Ta=25°C, VDD=5V, and with all color channels set to maximum brightness (8'b11111111).

• Luminous Intensity (Iv):
  • Red (AlInGaP): 340 mcd (Min), 800 mcd (Max)
  • Green (InGaN): 600 mcd (Min), 1500 mcd (Max)
  • Blue (InGaN): 150 mcd (Min), 360 mcd (Max)
• Viewing Angle (2θ1/2): 120 degrees (Typical). This is the full angle at which luminous intensity is half the on-axis intensity.
• Dominant Wavelength (λd):
  • Red: 615 nm to 630 nm
  • Green: 520 nm to 535 nm
  • Blue: 460 nm to 475 nm

2.3 Electrical Characteristics

Electrical parameters are specified over an ambient temperature range of -20°C to +70°C and a supply voltage (VDD) range of 4.2V to 5.5V.

• IC Output Current (IF): 20 mA (Typical) per color channel (Red, Green, Blue separately). This is the constant current set by the embedded driver.
• Input Voltage Levels:
  • High-Level Input Voltage (VIH): 2.7V min to VDD max for DIN and other control pins.
  • Low-Level Input Voltage (VIL): 0V min to 1.0V max.
• IC Working Current (IDD): 1.5 mA (Typical) when all LED data is set to '0' (off state).

2.4 Data Transfer Timing

The embedded IC uses a specific serial communication protocol. The total period for one bit (TH + TL) is 1.2μs ±300ns.

• T0H (0 code, high time): 300 ns ±150ns
• T0L (0 code, low time): 900 ns ±150ns
• T1H (1 code, high time): 900 ns ±150ns
• T1L (1 code, low time): 300 ns ±150ns
• RES (Reset time): >250 μs. A low signal on DIN lasting longer than this resets the IC.

3. Binning System Explanation

The product uses a CIE chromaticity coordinate-based binning system to ensure color consistency. The bins are defined by quadrilaterals on the CIE 1931 (x, y) chromaticity diagram. The provided table lists bin codes (A1, A2, A3, B1, B2, B3, C1, C2, C3) with the (x, y) coordinates for their four corner points (Point1 to Point4). The tolerance for each CIE (x, y) coordinate within a bin is +/- 0.01. This system allows designers to select LEDs from the same bin code to achieve uniform color appearance in an array or display.

4. Performance Curve Analysis

4.1 Relative Intensity vs. Wavelength

The spectral distribution graph shows the emission peaks for the three colors. The Red LED (using AlInGaP technology) has a dominant wavelength in the 615-630nm range. The Green and Blue LEDs (using InGaN technology) have peaks in the 520-535nm and 460-475nm ranges, respectively. The curves help understand the color purity and potential overlap between channels.

4.2 Forward Current vs. Ambient Temperature Derating Curve

This graph illustrates the maximum allowable forward current for the LED as a function of the ambient temperature. As temperature increases, the maximum permissible current decreases linearly to prevent overheating and ensure reliability. This is a critical graph for thermal management design.

4.3 Spatial Distribution (Luminous Intensity vs. Angle)

The polar diagram depicts the relative luminous intensity as a function of the viewing angle. The symmetrical, wide beam pattern with a 120-degree viewing angle confirms the "white diffused" lens description, providing a broad, even illumination suitable for indicator and backlighting applications.

5. Mechanical and Package Information

5.1 Package Dimensions and Pin Configuration

The component is a surface-mount device. The datasheet includes a detailed dimensional drawing. All dimensions are in millimeters with a standard tolerance of ±0.2 mm unless otherwise noted. The pin configuration is as follows:

1. VDD: DC power input (+4.2V to +5.5V).
2. DIN: Control data signal input.
3. VSS: Ground.
4. DOUT: Control data signal output (for cascading to the next LED's DIN).

5.2 Recommended PCB Attachment Pad Layout

A suggested land pattern (footprint) for the PCB is provided to ensure proper soldering and mechanical stability during assembly. Following this recommendation is essential for achieving good solder joint reliability.

6. Soldering and Assembly Guidelines

6.1 IR Reflow Soldering Profile

A detailed reflow soldering profile graph is provided, compliant with J-STD-020B for lead-free processes. It specifies the critical parameters: preheat, soak, reflow peak temperature, and cooling rates. Adhering to this profile is crucial to avoid thermal damage to the LED package and internal IC.

6.2 Cleaning

If cleaning after soldering is necessary, the LED should only be immersed in ethyl alcohol or isopropyl alcohol at normal temperature for less than one minute. The use of unspecified chemical cleaners is prohibited as they may damage the package material.

7. Packaging and Ordering Information

The device is supplied in a tape-and-reel format compatible with automated pick-and-place machines.

• Tape Dimensions: 12mm tape width.
• Reel Size: 7-inch (178mm) diameter.
• Quantity per Reel: 4000 pieces.
• Minimum Packing Quantity: 500 pieces for remainder lots.
• Cover Tape: Empty component pockets are sealed with a top cover tape.
• Specification: Packaging conforms to ANSI/EIA 481 standards.

8. Application Suggestions

8.1 Typical Application Scenarios

• Status Indicators & Backlighting: Ideal for multi-color status lights on consumer electronics, network equipment, and industrial panels.
• Decorative & Architectural Lighting: Suitable for color-changing LED strips, mood lighting, and accent lighting due to its full-color capability and cascading feature.
• Low-Resolution Displays: Can be used to build full-color modules, soft light lamps, and irregular indoor video displays (e.g., media facades, art installations).

8.2 Design Considerations

• Power Supply: Ensure a stable, regulated 5V supply within the 4.2V-5.5V range. Consider inrush current and decoupling capacitors near the VDD pin.
• Data Signal Integrity: Maintain the precise timing requirements (T0H, T1H, etc.) for the serial data signal. For long cascades or noisy environments, consider signal buffering or level shifting.
• Thermal Management: Adhere to the current derating curve. Provide adequate copper area on the PCB for heat dissipation, especially when driving all three channels at high brightness for extended periods.
• ESD Protection: Implement standard ESD protection measures on data and power lines during handling and in the final application.

9. Technical Comparison and Differentiation

Compared to traditional discrete RGB LEDs that require external constant-current drivers or resistors, this integrated solution offers significant advantages:

• Simplified Design: Reduces component count, PCB footprint, and design complexity.
• Superior Color Consistency: The embedded IC provides precise, stable constant current to each chip, leading to more consistent color output across units and over time compared to resistor-limited designs.
• High-Resolution Dimming: 8-bit PWM (256 steps) per color allows for smooth color mixing and dimming, enabling professional lighting effects.
• Daisy-Chaining Capability: The single-wire cascade protocol simplifies wiring for large arrays, requiring only one microcontroller GPIO pin to control a long chain of LEDs.

10. Frequently Asked Questions (Based on Technical Parameters)

Q: What is the purpose of the embedded IC?
A: It provides constant current drive and PWM dimming control for each color channel internally, eliminating the need for external current-limiting components and simplifying microcontroller control.

Q: How many LEDs can I connect in a chain?
A: Theoretically, a very large number, as each LED regenerates the data signal. The practical limit is determined by the data refresh rate required and the cumulative voltage drop on the power line (VDD). For long chains, power injection at multiple points is recommended.

Q: Can I drive this LED with a 3.3V microcontroller?
A: The data input high level (VIH) minimum is 2.7V. A 3.3V logic high (typically 3.3V) meets this requirement, so it is generally compatible. Ensure the 5V power supply for the LED (VDD) is separate from the microcontroller's 3.3V supply.

Q: Why is the forward current fixed at 20mA?
A: The embedded IC is pre-configured to deliver a constant 20mA (typical) to each LED chip. This optimizes performance and reliability. The brightness is controlled solely via the PWM duty cycle, not by varying the current amplitude.

11. Practical Use Case Example

Scenario: Designing a compact, color-customizable status indicator for a smart home hub.
The designer uses this LED because a single component provides red, green, and blue light. The microcontroller sends a simple serial data stream to set the color (e.g., red for offline, cyan for connected, purple for updating). The constant-current drive ensures the brightness remains stable regardless of minor power supply fluctuations. The wide viewing angle makes the indicator visible from various angles. The surface-mount package allows for a sleek, flat-panel design. The tape-and-reel packaging enables fast, automated assembly during mass production.

12. Operating Principle Introduction

The device operates on a simple principle. An external microcontroller sends a serial data stream into the DIN pin. This stream contains 24 bits of data (8 bits each for the red, green, and blue brightness levels). The embedded IC inside the first LED reads these first 24 bits, latches them, and then shifts the remaining data stream out through its DOUT pin to the DIN pin of the next LED in the chain. The IC then uses Pulse Width Modulation (PWM) to control the constant current sources connected to each LED chip. A 20mA current is switched on and off very rapidly. The ratio of on-time to off-time (duty cycle) within a fixed period determines the perceived brightness of each color, allowing for precise color mixing.

13. Technology Trends

The integration of control electronics directly into LED packages represents a clear trend in the industry, moving towards "smart" or "intelligent" LEDs. This trend aims to simplify end-product design, improve performance consistency, and enable more advanced features like individual addressability in dense arrays. Future developments may include higher bit-depth for color control (10-bit, 12-bit), integrated sensors (e.g., for temperature or light feedback), and communication protocols that are more robust or higher speed. The focus remains on increasing integration, reducing system cost, and improving reliability for applications in general lighting, automotive, and high-resolution displays.