LTW-C194TS5 SMD LED Datasheet - Dimensions 0.30mm Thin - Voltage 2.7-3.15V - White Color - English Technical Document

1. Product Overview

The LTW-C194TS5 is a surface-mount device (SMD) light-emitting diode (LED) designed for modern, space-constrained electronic applications. Its primary positioning is as a high-brightness, miniature indicator or backlighting component. The core advantage of this product lies in its exceptionally thin profile of 0.30 millimeters, enabling integration into ultra-slim devices such as smartphones, tablets, wearable technology, and ultra-portable laptops. The target market includes consumer electronics, industrial control panels, automotive interior lighting, and general-purpose indication where reliable, bright light output in a minimal package is required.

2. In-Depth Technical Parameter Analysis

2.1 Electrical and Optical Characteristics

The performance of the LTW-C194TS5 is specified at a standard ambient temperature (Ta) of 25°C. Key parameters define its operational envelope:

• Luminous Intensity (Iv): Ranges from a minimum of 56.0 millicandelas (mcd) to a typical value of 146.0 mcd when driven at a forward current (IF) of 5mA. This parameter is measured using equipment that approximates the CIE standard photopic observer eye-response curve, ensuring relevance to human vision.
• Viewing Angle (2θ1/2): A wide viewing angle of 130 degrees is specified, providing a broad, diffuse light emission pattern suitable for area illumination and wide-angle visibility.
• Chromaticity Coordinates (x, y): The color point of the white light is defined on the CIE 1931 chromaticity diagram. Typical coordinates are x=0.294 and y=0.286 at IF=5mA, with a guaranteed tolerance of ±0.01 for both coordinates. This defines a specific shade of white light.
• Forward Voltage (VF): The voltage drop across the LED when conducting 5mA of current falls between 2.70 Volts (min) and 3.15 Volts (max). This parameter is crucial for circuit design to ensure proper current limiting.
• Reverse Current (IR): A maximum of 10 microamperes (μA) flows when a reverse bias of 5 Volts is applied, indicating the diode's leakage characteristics.

2.2 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage may occur. They are not intended for normal operation.

• Power Dissipation (Pd): Maximum 70 mW.
• Forward Current: Continuous DC forward current is limited to 20 mA. A higher peak forward current of 100 mA is permissible under pulsed conditions (1/10 duty cycle, 0.1ms pulse width).
• Reverse Voltage (VR): Maximum 5 V. Operating under reverse bias is not recommended and may cause failure.
• Temperature Ranges: Operating: -20°C to +80°C. Storage: -40°C to +85°C.
• Soldering Condition: Withstands infrared reflow soldering with a peak temperature of 260°C for a duration of 10 seconds.

3. Binning System Explanation

To ensure consistency in mass production, LEDs are sorted into performance bins. The LTW-C194TS5 uses a three-dimensional binning system:

3.1 Forward Voltage (VF) Binning

LEDs are categorized based on their forward voltage at IF=5mA. This allows designers to select LEDs with similar voltage drops for uniform brightness in parallel circuits or for precise power management.

• Bin A: VF = 2.70V to 2.85V
• Bin B: VF = 2.85V to 3.00V
• Bin C: VF = 3.00V to 3.15V

Tolerance within each bin is ±0.1 Volt.

3.2 Luminous Intensity (IV) Binning

This binning sorts LEDs by their light output intensity, critical for applications requiring specific brightness levels.

• Bin P2: Iv = 56.0 mcd to 71.0 mcd
• Bin Q1: Iv = 71.0 mcd to 90.0 mcd
• Bin Q2: Iv = 90.0 mcd to 112.0 mcd
• Bin R1: Iv = 112.0 mcd to 146.0 mcd

Tolerance on each intensity bin is ±15%.

3.3 Hue (Color) Binning

The white light color is binned into six categories (S1 through S6) based on chromaticity coordinates (x, y) on the CIE 1931 diagram. Each bin defines a quadrilateral area on the color chart. This ensures color uniformity across multiple LEDs in an assembly. The tolerance for hue coordinates within a bin is ±0.01. A diagram is typically provided showing these bins overlaid on the chromaticity chart.

4. Performance Curve Analysis

While specific graphical curves are referenced in the datasheet, their implications are standard. Designers can expect the following general relationships:

• IV Curve (Current vs. Voltage): The forward voltage (VF) increases logarithmically with forward current (IF). Operating significantly above the recommended 5mA test current will increase VF and power dissipation.
• Luminous Intensity vs. Current: Light output is generally proportional to forward current within the operational range, but efficiency may drop at very high currents due to heating.
• Temperature Dependence: Luminous intensity typically decreases as the junction temperature increases. The wide operating temperature range (-20°C to +80°C) indicates stable performance across environmental conditions, though derating may be necessary at high temperatures.

5. Mechanical and Package Information

5.1 Package Dimensions

The LED features an industry-standard EIA package outline. All critical dimensions, including length, width, height (0.30mm), and lead spacing, are provided in millimeter-based drawings. A polarity indicator (typically a cathode mark or a notch) is included in the drawing to ensure correct orientation during assembly.

5.2 Recommended Solder Pad Design

A land pattern (footprint) recommendation is provided for PCB design. This includes the size and shape of the copper pads to which the LED will be soldered. Adhering to this recommendation is crucial for achieving reliable solder joints, proper self-alignment during reflow, and effective heat dissipation. A note suggests a maximum stencil thickness of 0.10mm for solder paste application.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Parameters

The component is fully compatible with infrared (IR) reflow soldering processes. A suggested profile is provided:

• Pre-heat: 150°C to 200°C.
• Pre-heat Time: Maximum 120 seconds.
• Peak Temperature: Maximum 260°C.
• Time Above Liquidus: 10 seconds maximum (recommended for a maximum of two reflow cycles).

These parameters are based on JEDEC standards to ensure reliability. The datasheet emphasizes that the optimal profile depends on the specific PCB assembly setup (board type, other components, oven).

6.2 Hand Soldering

If hand soldering is necessary, it should be performed with extreme care due to the component's small size and heat sensitivity:

• Iron Temperature: Maximum 300°C.
• Contact Time: Maximum 3 seconds per pad.
• Frequency: One time only; avoid rework.

6.3 Storage and Handling

• ESD Precautions: The LED is sensitive to electrostatic discharge (ESD). Handling should involve grounded wrist straps, anti-static mats, and properly grounded equipment.
• Moisture Sensitivity: As a miniature SMD component, it is moisture-sensitive. When in its sealed, original packaging (with desiccant), it should be stored at ≤30°C and ≤90% RH and used within one year. Once the moisture-proof bag is opened, the LEDs should be stored at ≤30°C and ≤60% RH and ideally reflowed within one week. For longer storage out of the original bag, use a sealed container with desiccant. Components stored out of bag for more than a week require baking (approx. 60°C for at least 20 hours) before soldering to prevent "popcorning" during reflow.

6.4 Cleaning

If post-solder cleaning is required, only specified solvents should be used to avoid damaging the plastic lens or package. Recommended agents are ethyl alcohol or isopropyl alcohol at normal temperature, with an immersion time of less than one minute.

7. Packaging and Ordering Information

7.1 Tape and Reel Specifications

The LTW-C194TS5 is supplied packaged for automated pick-and-place assembly machines:

• Carrier Tape: 8mm wide tape.
• Reel Size: 7-inch (178mm) diameter reel.
• Quantity per Reel: 5,000 pieces.
• Minimum Order Quantity (MOQ): 500 pieces for remainder quantities.
• Packaging Standard: Complies with ANSI/EIA 481-1 specifications. Empty pockets in the tape are sealed with a cover tape.

8. Application Suggestions and Design Considerations

8.1 Typical Application Scenarios

• Status Indicators: Power, connectivity, or function status lights in ultra-thin consumer electronics.
• Backlighting: Edge-lit or direct backlighting for small LCD displays, keypads, or symbols.
• Decorative Lighting: Accent lighting in automotive interiors, home appliances, or gaming peripherals.
• General Illumination: Low-level area lighting in compact devices.

8.2 Critical Design Considerations

• Current Limiting: Always use a series current-limiting resistor or a constant-current driver. Do not connect directly to a voltage source. The recommended test current is 5mA, but the absolute maximum continuous current is 20mA. Design for the appropriate brightness and power dissipation.
• Thermal Management: Despite its low power, ensure adequate PCB copper area or thermal vias under the solder pads to conduct heat away from the LED junction, especially when operating near maximum ratings or in high ambient temperatures. This maintains light output and longevity.
• Optical Design: The 130-degree viewing angle provides a wide beam. For focused light, external lenses or light guides may be necessary. The yellow lens material will affect the final perceived color.
• Binning Selection: For applications requiring uniform appearance (e.g., multi-LED arrays), specify tight bins for VF, Iv, and Hue (Color) to minimize variations in brightness and color.

9. Technical Comparison and Differentiation

The primary differentiating factors of the LTW-C194TS5 are its ultra-thin 0.30mm profile and its use of an InGaN (Indium Gallium Nitride) white chip. Compared to older technology like blue chip with phosphor, InGaN-based white LEDs often offer benefits in terms of efficiency, color rendering potential, and stability. The thinness is a key mechanical advantage over standard SMD LEDs (which are often 0.6mm or thicker), enabling design in the latest generation of slim devices. Its compatibility with standard IR reflow and EIA package outlines ensures it can be a drop-in replacement or upgrade in many existing designs seeking miniaturization.

10. Frequently Asked Questions (Based on Technical Parameters)

10.1 What is the purpose of the three different binning categories?

Binning ensures electrical and optical consistency. VF binning helps in power supply design and parallel LED circuits. Iv binning guarantees a specific brightness level. Hue binning is critical for color-matching in multi-LED applications to avoid noticeable color differences.

10.2 Can I drive this LED at 20mA continuously?

While the absolute maximum rating is 20mA DC, the standard test condition and typical performance data are given at 5mA. Operating at 20mA will produce higher light output but will also generate more heat, increase forward voltage, and potentially reduce long-term reliability. It is essential to perform thermal analysis and possibly derate the maximum current based on the actual operating environment.

10.3 Why is there such a strict storage and baking requirement?

The ultra-thin plastic package can absorb moisture from the air. During the high-temperature reflow soldering process, this trapped moisture can vaporize rapidly, creating internal pressure that can crack the package or delaminate internal bonds ("popcorning"). The storage and baking procedures are designed to remove this moisture safely before soldering.

10.4 How do I interpret the chromaticity coordinates (x=0.294, y=0.286)?

These coordinates plot a point on the CIE 1931 chromaticity diagram, which maps all perceivable colors. This specific point corresponds to a particular shade of white light, often described as "cool white." The ±0.01 tolerance defines a small area around this point within which the LED's color is guaranteed to fall.

11. Practical Design and Usage Case

Case: Designing a Status Indicator Bar for a Slim Tablet. A designer needs five uniform white LEDs for a charge-level indicator bar. The space behind the bezel is extremely limited (0.4mm). They select the LTW-C194TS5 for its 0.30mm height. To ensure uniformity, they specify Bin B for VF (2.85-3.00V), Bin R1 for Iv (112-146 mcd), and Bin S3 for Hue. They design the PCB footprint exactly as recommended, with a small thermal relief pad connected to an internal ground plane for heat sinking. A constant-current driver set to 5mA per LED is used. The LEDs are ordered on 7-inch reels for automated assembly. The factory follows the prescribed reflow profile and stores opened reels in a dry cabinet, baking them before use after a weekend shutdown. The result is a bright, even, and reliable indicator bar that fits the mechanical design constraints.

12. Technical Principle Introduction

The LTW-C194TS5 is based on InGaN semiconductor technology. In a white LED, typically a blue-emitting InGaN chip is combined with a yellow phosphor coating inside the package. When the chip emits blue light, part of it is absorbed by the phosphor and re-emitted as yellow light. The mixture of the remaining blue light and the converted yellow light is perceived by the human eye as white light. The specific ratios of the chip emission and phosphor composition determine the final chromaticity coordinates (color point) on the white light spectrum. The ultra-thin package is achieved through advanced molding and wafer-level packaging techniques that minimize the material above and below the semiconductor die.

13. Industry Trends and Developments

The trend in SMD LEDs for consumer electronics is relentlessly towards miniaturization (thinner, smaller footprints) and increased efficiency (more light output per unit of electrical power and per unit of area). The 0.30mm profile of this LED represents a step in this direction. Furthermore, there is a continuous drive for improved color consistency and higher Color Rendering Index (CRI) in white LEDs, achieved through advancements in phosphor technology and chip design. Another trend is the integration of more features, such as built-in ICs for control (making "smart LEDs"), though the LTW-C194TS5 appears to be a standard discrete component. The compatibility with lead-free (RoHS) and high-temperature reflow processes remains a fundamental requirement driven by global environmental regulations and assembly standards.