LTL-14FM9HKP LED Lamp Datasheet - Right Angle Holder - Yellow Green/Red/Yellow - 20mA - 52mW - English Technical Document

1. Product Overview

The LTL-14FM9HKP is a Circuit Board Indicator (CBI) designed for through-hole mounting. It consists of a black plastic right-angle holder (housing) that mates with specific LED lamps. This design is intended to enhance contrast ratio and facilitate easy assembly on printed circuit boards (PCBs). The product is available in configurations featuring AlInGaP semiconductor chips emitting in yellow green, red, and yellow wavelengths.

1.1 Core Advantages

• Ease of Assembly: The design is optimized for straightforward circuit board assembly processes.
• Enhanced Contrast: The black plastic housing provides a high contrast background, improving the visibility of the illuminated LED.
• Energy Efficiency: The device features low power consumption and high luminous efficiency.
• Environmental Compliance: This is a lead-free product compliant with RoHS (Restriction of Hazardous Substances) directives.
• Chip Technology: Utilizes AlInGaP (Aluminum Indium Gallium Phosphide) chips, known for their efficiency and color purity in the red to yellow-green spectrum.

1.2 Target Applications

This LED indicator is suitable for a broad range of electronic equipment, including:

• Computer peripherals and internal status indicators.
• Communication equipment for signal and status display.
• Consumer electronics.
• Industrial control panels and machinery.

2. In-Depth Technical Parameter Analysis

The following section provides a detailed breakdown of the key electrical, optical, and thermal parameters specified for the LTL-14FM9HKP.

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. All values are specified at an ambient temperature (TA) of 25°C.

• Power Dissipation (PD): 52 mW maximum for all LED colors. This is the maximum power the device can dissipate without exceeding its thermal limits.
• Peak Forward Current (IFP): 60 mA, permissible only under pulsed conditions (duty cycle ≤ 1/10, pulse width ≤ 10ms).
• Continuous Forward Current (IF): 20 mA DC. This is the recommended maximum current for continuous operation.
• Operating Temperature Range: -30°C to +85°C. The device is guaranteed to function within this ambient temperature range.
• Storage Temperature Range: -40°C to +100°C.
• Lead Soldering Temperature: 260°C for a maximum of 5 seconds, measured 2.0mm (0.079\") from the body of the component.

2.2 Electrical & Optical Characteristics

These are the typical performance parameters measured at TA=25°C and IF=10mA, unless otherwise noted.

• Luminous Intensity (Iv):
  • LED1 (Yellow Green): Typical 15 mcd (Min 8.7, Max 29 mcd).
  • LED2 (Yellow Green): Typical 15 mcd (Min 8.7, Max 29 mcd).
  • LED2 (Red): Typical 14 mcd (Min 3.8, Max 30 mcd).
  • LED3 (Yellow): Typical 11 mcd (Min 3.8, Max 30 mcd).
  • Note: Iv measurement includes a ±30% testing tolerance.
• Viewing Angle (2θ1/2): Defined as the full angle where intensity drops to half its peak value.
  • LED1 & LED3: 100 degrees.
  • LED2 (both colors): 110 degrees.
• Wavelength:
  • Peak Wavelength (λP): The wavelength at which the emission spectrum is strongest. LED1/2 Yellow Green: 572nm, LED2 Red: 630nm, LED3 Yellow: 591nm.
  • Dominant Wavelength (λD): The single wavelength perceived by the human eye, derived from CIE coordinates. Typical values: Yellow Green: 569nm, Red: 625nm, Yellow: 589nm.
• Spectral Line Half-Width (Δλ): A measure of color purity. Yellow Green/Yellow: 15nm, Red: 20nm.
• Forward Voltage (VF): Typical 2.0V for all colors at 10mA (range 1.6V to 2.5V). This low voltage is characteristic of AlInGaP technology.
• Reverse Current (IR): Maximum 10 μA at VR=5V. The device is not designed for reverse bias operation; this parameter is for leakage test purposes only.

3. Performance Curve Analysis

The datasheet provides typical characteristic curves which are essential for circuit design and understanding device behavior under varying conditions.

3.1 Relative Luminous Intensity vs. Forward Current

These curves show that luminous intensity increases with forward current in a non-linear relationship. For optimal brightness and longevity, operation at or below the recommended 20mA is advised. Driving the LED beyond this point yields diminishing returns in light output and increases heat generation.

3.2 Forward Voltage vs. Forward Current

The V-I curves demonstrate the diode-like behavior. The forward voltage exhibits a slight positive temperature coefficient, meaning it decreases as the junction temperature rises for a given current. This is an important consideration for constant-voltage drive circuits.

3.3 Relative Luminous Intensity vs. Ambient Temperature

These curves illustrate the thermal derating of light output. Luminous intensity decreases as ambient temperature increases. This is a critical factor for applications operating in elevated temperature environments, as it may necessitate current adjustment or heat sinking to maintain desired brightness levels.

4. Mechanical & Packaging Information

4.1 Outline Dimensions

The device uses a right-angle through-hole form factor. Key dimensional notes include:

• All primary dimensions are in millimeters, with a standard tolerance of ±0.25mm unless otherwise specified.
• The holder (housing) material is black/dark gray plastic.
• LED identification: LED1 has a green diffused lens, LED2 has a white diffused lens, and LED3 has a yellow diffused lens.

4.2 Polarity Identification

Polarity is indicated by the physical structure of the holder and the lead lengths (typically the cathode lead is shorter or marked). The outline drawing in the datasheet must be consulted for the specific pinout configuration of each LED color within the holder.

4.3 Packing Specification

The components are supplied in bulk packaging or on tape and reel for automated assembly. The exact reel dimensions, pocket spacing, and orientation are detailed in the packing specification diagram.

5. Soldering & Assembly Guidelines

Proper handling is crucial for reliability.

5.1 Storage Conditions

For long-term storage outside the original packaging, it is recommended to store LEDs in a sealed container with desiccant or in a nitrogen ambient to prevent moisture absorption, which can affect soldering and long-term performance. Use within three months if removed from original packaging.

5.2 Lead Forming

• Bending must be performed at a point at least 3mm from the base of the LED lens.
• Do not use the base of the lead frame as a fulcrum.
• Lead forming must be done before soldering and at room temperature.
• Use minimum clinch force during PCB assembly to avoid mechanical stress.

5.3 Soldering Process

Critical Rule: Maintain a minimum clearance of 2mm from the base of the lens/holder to the soldering point. Do not immerse the lens or holder in solder.

• Hand Soldering (Iron): Maximum temperature 350°C, maximum time 3 seconds per lead (one time only).
• Wave Soldering:
  • Pre-heat: Maximum 120°C for up to 100 seconds.
  • Solder Wave: Maximum 260°C for up to 5 seconds.
  • Ensure the device is positioned so the solder wave does not come within 2mm of the lens/holder base.
• Not Recommended: IR reflow soldering is not suitable for this through-hole type product.
• Warning: Excessive temperature or time can cause lens deformation or catastrophic LED failure. The maximum wave soldering temperature is not indicative of the holder's Heat Deflection Temperature (HDT) or melting point.

6. Application & Circuit Design Recommendations

6.1 Drive Circuit Design

LEDs are current-operated devices. To ensure uniform brightness when multiple LEDs are used, especially in parallel, a current-limiting resistor must be placed in series with each LED.

• Recommended Circuit (A): Each LED has its own series resistor connected to the voltage supply. This compensates for variations in the forward voltage (Vf) of individual LEDs, ensuring each receives the same current and thus emits similar brightness.
• Non-Recommended Circuit (B): Multiple LEDs connected in parallel with a single shared resistor. Due to natural Vf variations between LEDs, the current will not divide equally, leading to significant differences in brightness between devices.

6.2 Electrostatic Discharge (ESD) Protection

These LEDs are susceptible to damage from electrostatic discharge or power surges. Precautions must be taken during handling and assembly:

• Operators should wear conductive wrist straps or anti-static gloves.
• Use grounded workstations and tools.
• Store and transport components in ESD-protective packaging.

6.3 Cleaning

If cleaning is necessary after soldering, use only alcohol-based solvents such as isopropyl alcohol. Avoid harsh or abrasive cleaners.

7. Technical Comparison & Design Considerations

7.1 Technology Choice: AlInGaP

The use of Aluminum Indium Gallium Phosphide (AlInGaP) semiconductor material offers distinct advantages for colors in the red, orange, yellow, and yellow-green spectrum:

• High Efficiency: AlInGaP LEDs generally offer higher luminous efficacy (lumens per watt) in these colors compared to older technologies like GaAsP.
• Good Color Purity: The spectral half-width is relatively narrow (15-20nm), resulting in saturated, pure colors.
• Thermal Stability: The performance degradation with temperature, while present, is managed and characterized in the provided curves.

7.2 Form Factor: Right-Angle Through-Hole

This design is ideal for applications where the PCB is mounted vertically or where the indicator needs to be visible from the front panel while the board is parallel to it. The black housing provides built-in light piping and contrast enhancement, eliminating the need for a separate bezel or light guide in many designs.

8. Frequently Asked Questions (Based on Technical Data)

8.1 Can I drive this LED at 20mA continuously?

Yes, 20mA DC is the specified maximum continuous forward current. For optimal lifetime and reliability, operating at or slightly below this value (e.g., 15-18mA) is often recommended, especially in high ambient temperature conditions.

8.2 Why is a series resistor necessary even if my supply voltage matches the LED's typical Vf?

The forward voltage (Vf) has a tolerance range (1.6V to 2.5V). A constant voltage source cannot regulate current. A small increase in voltage can cause a large, potentially damaging, increase in current due to the diode's exponential I-V characteristic. The series resistor provides negative feedback, stabilizing the current against variations in both supply voltage and the LED's individual Vf.

8.3 Can I use reflow soldering for this component?

No. The datasheet explicitly states that IR reflow is not a suitable process for this through-hole type LED lamp. The recommended processes are hand soldering or wave soldering with the strict temperature and clearance guidelines provided.

8.4 How do I calculate the series resistor value?

Use Ohm's Law: R = (V_supply - Vf_LED) / I_desired.
Example: For a 5V supply, a typical Vf of 2.0V, and a desired current of 10mA:
R = (5V - 2.0V) / 0.010A = 300 Ohms.
Always consider the worst-case Vf (minimum) to ensure current does not exceed maximum limits, and verify power dissipation in the resistor (P = I^2 * R).