Dual-Color SMD LED RF-P3S155TS-B54 Datasheet - Size 3.2x2.7x0.7mm - Voltage 1.8-3.4V - Power 72-102mW - Orange/Green - English Technical Document

1. Product Overview

This document provides the complete technical specification for the RF-P3S155TS-B54, a dual-color surface-mount LED component. The device is designed for modern electronic assemblies requiring reliable optical indication in a compact form factor.

1.1 General Description

The RF-P3S155TS-B54 is a dual-color LED fabricated using a combination of a green semiconductor chip and an orange semiconductor chip. These chips are integrated into a single, industry-standard surface-mount device (SMD) package. The primary function of this component is to provide visual status indication, capable of emitting two distinct colors (orange and green) from a single package footprint. The compact dimensions of 3.2mm in length, 2.7mm in width, and a profile height of 0.7mm make it suitable for high-density PCB designs where board space is at a premium.

1.2 Core Features and Advantages

• Extremely Wide Viewing Angle: The device features a typical viewing angle (2θ1/2) of 140 degrees. This wide emission pattern ensures the LED's light is visible from a broad range of perspectives, which is critical for status indicators on consumer electronics, industrial panels, and automotive dashboards where the user's viewing position may vary.
• SMT Assembly Compatibility: The package is fully compatible with standard Surface Mount Technology (SMT) assembly lines and all common solder reflow processes (e.g., using SAC305 or similar lead-free solder pastes). This allows for high-speed, automated pick-and-place manufacturing, reducing assembly costs and improving production yield.
• Moisture Sensitivity: The component is rated at Moisture Sensitivity Level (MSL) 3. According to the IPC/JEDEC J-STD-033 standard, this means the device can be exposed to factory floor conditions (≤ 30°C/60% RH) for up to 168 hours (7 days) before it requires baking prior to reflow soldering. This level offers a good balance between handling convenience and reliability for most manufacturing environments.
• Environmental Compliance: The product is compliant with the RoHS (Restriction of Hazardous Substances) directive, meaning it is free from lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB), and polybrominated diphenyl ethers (PBDE). This compliance is essential for products sold in the European Union and many other global markets.

1.3 Target Applications and Market

This dual-color LED is designed for a versatile range of applications where multi-state indication is required. Its primary uses include:

• Optical Status Indicators: Providing clear visual feedback for power on/off, standby mode, network activity, battery charging status, or system errors in devices such as routers, modems, chargers, and smart home appliances.
• Switch and Symbol Illumination: Backlighting for membrane switches, push buttons, or engraved symbols on control panels, medical equipment, and automotive interiors.
• General Purpose Display: Used in segment displays, cluster indicators, or as simple pixel elements in low-resolution informational displays.
• Target Markets: Consumer electronics, telecommunications hardware, industrial automation controls, automotive interior electronics, and portable electronic devices.

2. In-Depth Technical Parameter Analysis

This section provides a detailed, objective interpretation of the electrical, optical, and thermal parameters specified for the RF-P3S155TS-B54 LED. Understanding these parameters is crucial for proper circuit design and ensuring long-term reliability.

2.1 Electro-Optical Characteristics

All measurements are defined at a standard test condition of a solder point temperature (Ts) of 25°C and a forward current (IF) of 20mA, unless otherwise noted.

• Forward Voltage (VF): This is the voltage drop across the LED when operating at the specified current.
  • Orange Chip (Code O): Ranges from a minimum of 1.8V to a maximum of 2.4V, with a typical value implied within this range. The specific bin (e.g., 1L) determines the exact VF grouping.
  • Green Chip (Code G): Has a higher forward voltage, ranging from 3.0V to 3.4V (bin 3E). This difference is due to the different semiconductor materials (e.g., AlInGaP for orange vs. InGaN for green) used for each color, which have different bandgap energies.
• Luminous Intensity (Iv): A measure of the perceived power of light emitted in a particular direction, measured in millicandelas (mcd). The device is available in multiple intensity bins for each color, allowing designers to select the appropriate brightness level.
  • Orange Bins: Examples include 1AP (90-120 mcd) and G20 (120-150 mcd).
  • Green Bins: Offers a wider range of higher intensities, from 1AU (260-330 mcd) up to 1CM (700-900 mcd).
• Dominant Wavelength (λd): The single wavelength that best represents the perceived color of the light.
  • Orange: Available in bins like E00 (620-625 nm) and F00 (625-630 nm), producing a pure orange hue.
  • Green: Available in finer bins such as E10 (520-522.5 nm), E20 (522.5-525 nm), etc., allowing for precise color matching, which is important in applications where consistent green tone is critical.
• Spectral Half Bandwidth (Δλ): The width of the emitted spectrum at half its maximum intensity. The orange chip has a typical bandwidth of 15nm, while the green chip has a broader 30nm bandwidth. A narrower bandwidth indicates a more spectrally pure color.
• Reverse Current (IR): The leakage current when a reverse voltage (VR) of 5V is applied. The maximum specified is 10 µA. Exceeding the absolute maximum reverse voltage (not explicitly stated but implied by the ESD rating) can cause immediate damage.
• Viewing Angle (2θ1/2): The full angle at which the luminous intensity is half of the intensity at 0 degrees (on-axis). The specified 140-degree angle confirms the "extremely wide viewing angle" feature.

2.2 Absolute Maximum Ratings and Thermal Management

These ratings define the limits beyond which permanent damage to the device may occur. Operation under or at these limits is not guaranteed and should be avoided for reliable performance.

• Power Dissipation (Pd): The maximum allowable power that can be dissipated as heat.
  • Orange Chip: 72 mW
  • Green Chip: 102 mW
  This difference is directly related to the higher forward voltage of the green chip (Pd ≈ IF * VF).
• Forward Current (IF): The maximum continuous DC current is 30 mA for both chips.
• Peak Forward Current (IFP): A higher current of 60 mA is allowed only under pulsed conditions (0.1ms pulse width, 1/10 duty cycle) to prevent excessive heating.
• Junction Temperature (Tj): The maximum allowable temperature at the semiconductor junction is 95°C. This is a critical parameter for longevity. The LED's light output degrades faster at higher junction temperatures, and exceeding this limit can lead to catastrophic failure.
• Thermal Resistance (RθJ-S): This parameter, specified as 450 °C/W, quantifies how effectively heat travels from the semiconductor junction (J) to the solder point (S) of the package. A lower number is better. This value is used to calculate the junction temperature rise above the board temperature: ΔTj = Pd * RθJ-S. For example, operating the green chip at its maximum Pd of 102mW would cause a junction temperature rise of approximately 46°C above the solder point temperature. Therefore, maintaining a low PCB temperature is essential to keep Tj below 95°C.
• Electrostatic Discharge (ESD): The device can withstand 1000V using the Human Body Model (HBM). While this provides basic handling protection, proper ESD controls during assembly are still mandatory.
• Operating & Storage Temperature: The device is rated for environments from -40°C to +85°C.

2.3 Binning System Explanation

The product uses a comprehensive binning system to ensure consistency in key parameters. Designers must specify the desired bin codes when ordering to guarantee the required performance.

• Forward Voltage Binning: Orange chips are grouped under code "1L" (1.8-2.4V), and green chips under "3E" (3.0-3.4V).
• Dominant Wavelength Binning: This is particularly detailed for the green chip, with multiple 2.5nm wide bins (E10, E20, F10, F20) to allow for precise color selection. Orange has broader bins (E00, F00).
• Luminous Intensity Binning: Both colors have multiple intensity bins. For example, green intensity ranges from 1AU (260-330 mcd) to 1CM (700-900 mcd). The choice depends on the required brightness and the driving current used.

3. Performance Curve Analysis

The datasheet provides typical characteristic curves which are essential for understanding the device's behavior under non-standard conditions.

3.1 Forward Voltage vs. Forward Current (IV Curve)

The provided curve (Fig.1-6) shows the non-linear relationship between voltage and current for an LED. The curve demonstrates the "turn-on" voltage characteristic: a small increase in voltage beyond the threshold leads to a large, exponential increase in current. This is why LEDs are always driven with a current-limiting device (resistor or constant-current driver) and not directly with a voltage source. The curve visually confirms the different threshold voltages for the orange and green chips.

3.2 Forward Current vs. Relative Luminous Intensity

The curve (Fig.1-7) illustrates how light output increases with drive current. It typically shows a near-linear relationship in the normal operating range (e.g., up to 20-30mA). However, designers must be aware that efficiency (lumens per watt) often decreases at very high currents due to increased heat generation (droop effect). This curve helps in selecting the appropriate drive current to achieve the desired brightness while maintaining efficiency and staying within thermal limits.

4. Mechanical and Package Information

4.1 Package Dimensions and Tolerances

The mechanical drawings (Fig.1-1 to 1-4) provide all critical dimensions for PCB footprint design and clearance checks.

• Overall Size: 3.20mm (L) x 2.70mm (W) x 0.70mm (H). Tolerances are ±0.2mm unless otherwise specified.
• Terminal Details: The four solder terminals are on a 2.35mm pitch. The terminals themselves have dimensions of 0.80mm x 0.50mm.
• Polarity Identification: Figure 1-4 clearly indicates the polarity. The cathode is typically identified by a marking on the top of the package (like a dot, notch, or color stripe) and/or a different shape or size of the solder pad on the bottom. The exact marking should be verified from the drawing for correct orientation during assembly.

4.2 Recommended Solder Pad Design

Figure 1-5 provides a land pattern recommendation for PCB design. Following this pattern is crucial for achieving reliable solder joints, proper self-alignment during reflow, and effective heat transfer from the LED to the PCB. The recommended pattern typically includes thermal relief connections to a copper pad for heat sinking, which is vital for managing the junction temperature.

5. Soldering and Assembly Guidelines

5.1 SMT Reflow Soldering Instructions

A dedicated section (Section 3) is included for reflow soldering. While specific temperature profiles are not detailed in the provided excerpt, standard lead-free (SAC305) reflow profiles are generally applicable. Key considerations include:

• Pre-Conditioning: Due to the MSL 3 rating, if the devices have been exposed beyond the 168-hour floor life, they must be baked according to IPC/JEDEC standards (e.g., 125°C for 5-48 hours depending on packaging) to remove moisture and prevent "popcorning" (package cracking) during reflow.
• Profile Parameters: The peak reflow temperature must be controlled to avoid damaging the LED's internal materials and wire bonds. The profile should have a controlled ramp-up, a sufficient time above liquidus (TAL), and a controlled cooling rate.
• No-Clean Flux: The use of no-clean flux is recommended. If cleaning is necessary, it must be compatible with the LED's epoxy lens material to avoid clouding or chemical attack.

5.2 Handling and Storage Precautions

Section 4 outlines general handling precautions:

• ESD Protection: Handle in an ESD-protected area using grounded equipment.
• Mechanical Stress: Avoid applying direct force to the transparent lens.
• Contamination: Keep the lens clean from fingerprints, dust, and flux residues, as these can affect light output and appearance.
• Storage: Store in the original moisture barrier bag with desiccant in a cool, dry environment. Respect the MSL 3 exposure limits.

6. Packaging and Ordering Information

6.1 Packaging Specification

The product is supplied in tape-and-reel packaging suitable for automated SMT assembly machines.

• Carrier Tape: Dimensions for the embossed pocket that holds the LED are specified to ensure compatibility with feeder equipment.
• Reel Dimensions: Standard reel sizes (e.g., 7-inch or 13-inch diameter) are specified, including reel width, hub diameter, and maximum component quantity per reel.
• Label Information: The reel label contains critical information such as part number (RF-P3S155TS-B54), quantity, bin codes for wavelength and intensity, date code, and lot number for traceability.

6.2 Moisture-Resistant Packing

For long-term storage and shipping, the reels are packed in sealed moisture barrier bags (MBB) with a humidity indicator card (HIC) and desiccant to maintain the MSL 3 rating.

7. Reliability and Quality Assurance

7.1 Reliability Test Items and Conditions

Section 2.4 lists standard reliability tests performed to qualify the product, such as:

• High Temperature Storage Life (HTSL): Exposing the device to its maximum storage temperature (+85°C) for an extended period (e.g., 1000 hours) to test for material stability.
• Temperature Cycling (TC): Cycling between extreme temperatures (e.g., -40°C to +85°C) to test for failures due to thermal expansion mismatch of materials.
• Humidity Testing: Tests like 85°C/85% RH to assess resistance to moisture ingress.
• Solder Heat Resistance: Subjecting the device to multiple reflow cycles to simulate assembly conditions.

7.2 Failure Criteria

Section 2.5 defines the criteria for judging a device as failed after reliability testing. This typically includes:

• Catastrophic failure (no light output).
• Parametric failure (e.g., luminous intensity degrades by more than 30%, forward voltage shifts beyond specified limits).
• Visual defects (cracks in the package, discoloration of the lens).

8. Application Notes and Design Considerations

8.1 Driving Circuit Design

Current Limiting is Mandatory: Due to the exponential IV characteristic, a simple series resistor is the most common and cost-effective driving method for indicator applications. The resistor value is calculated using Ohm's Law: R = (Vcc - VF) / IF, where Vcc is the supply voltage, VF is the forward voltage of the specific LED bin, and IF is the desired drive current (e.g., 20mA).

Example for Green LED: With Vcc = 5V, VF = 3.2V (typical), IF = 20mA. R = (5 - 3.2) / 0.02 = 90 Ω. The resistor power rating should be at least P = IF² * R = (0.02)² * 90 = 0.036W, so a standard 1/8W (0.125W) or 1/10W resistor is sufficient.

Dual-Color Control: To independently control the two colors, two separate driving circuits (resistors or transistors) are needed, connected to the respective anode terminals while sharing a common cathode (or vice-versa, depending on the internal chip configuration shown in the polarity diagram).

8.2 Thermal Management in PCB Layout

To ensure the junction temperature (Tj) stays below 95°C, heat must be dissipated effectively.

• Thermal Pad Connection: Connect the solder pads, especially the cathode pad if it's thermally enhanced, to a generous area of copper on the PCB. This copper acts as a heat sink.
• Vias to Internal Planes: Use multiple thermal vias under or near the LED pads to conduct heat to internal ground or power planes, which have a large thermal mass.
• Avoid Isolation: Do not isolate the LED pads on small "thermal islands." Connect them to larger copper pours.
• Calculating Tj: Estimate Tj using the formula: Tj = Ts + (Pd * RθJ-S). Ts (solder point temperature) can be estimated as slightly above the ambient temperature (Ta) near the PCB. If Ta=50°C and the board temperature rise is 10°C, then Ts=60°C. For the green LED at Pd=102mW, Tj = 60 + (0.102 * 450) = 60 + 45.9 = 105.9°C. This exceeds the 95°C limit, indicating a need for better heat sinking (larger copper area, vias) or a reduction in drive current/power dissipation.

8.3 Optical Design Considerations

• Viewing Angle: The 140-degree viewing angle means light is emitted in a near-hemispherical pattern. For applications requiring a more directed beam, a secondary optic (lens) may be placed over the LED.
• Color Mixing: When both the orange and green chips are energized simultaneously, they will mix additively. The resulting perceived color will be a yellowish hue, depending on the relative intensity of each chip. This can be used to create a third color state without adding another component.
• Contrast Ratio: When designing the indicator's surround or light pipe, consider the contrast between the LED's "on" state and the unlit surface. Dark surrounds improve perceived brightness.

9. Technical Comparison and Differentiation

The RF-P3S155TS-B54 offers specific advantages in its category:

• vs. Single-Color LEDs: The primary advantage is space savings and simplified assembly. It provides two distinct indicator states (or three, including mixed color) in the footprint of a single component, reducing PCB area and placement machine time compared to using two separate LEDs.
• vs. RGB LEDs: This device is simpler and often more cost-effective than a full RGB LED when only two specific colors (orange and green) are needed, such as for standard "status/activity" or "okay/warning" indicators. It avoids the complexity and cost of a three-channel driver.
• vs. Larger Packages: The 3.2x2.7mm footprint is a common industry size, offering a good balance between ease of handling/manufacturing and space savings compared to larger packages like 5.0mm round LEDs or 0603/0805 chip LEDs.

10. Frequently Asked Questions (FAQ)

Q1: Can I drive this LED directly from a 5V microcontroller pin?

A: No. A microcontroller GPIO pin typically cannot source 20mA continuously and is a voltage source, not a current source. You must use a series current-limiting resistor and possibly a transistor if the MCU pin cannot source the required current.

Q2: What happens if I exceed the maximum junction temperature of 95°C?

A: Exceeding Tj max will accelerate the degradation of the LED's light output (lumen depreciation). It can also lead to increased forward voltage, color shift, and ultimately, catastrophic failure like wire bond breakage or chip delamination.

Q3: How do I select the correct bin codes?

A: Select bins based on your application's requirements. For consistent color across products, specify tight wavelength bins (e.g., E20 for green). For brightness, choose an intensity bin that meets your design goals at your chosen drive current. Consult the manufacturer's full bin code list for available combinations.

Q4: Is the lens made of silicone or epoxy?

A: The datasheet does not specify, but most SMD LEDs of this type use a high-temperature epoxy or modified epoxy for the encapsulant lens. This material is selected for its optical clarity, thermal stability during reflow, and ability to protect the chip.

11. Practical Design and Usage Case Study

Scenario: Designing a Dual-Status Indicator for a Network Switch

A designer needs an indicator for each port on a network switch: solid green for "Link Active" and blinking orange for "Data Activity.\