Ceramic 3535 Series 1W Red LED Specification - Dimensions 3.5x3.5mm - Voltage 2.2V - Power 1W - English Technical Document

1. Product Overview

This document details the specifications for a high-power, surface-mount LED utilizing a ceramic 3535 package. The primary component is a 1W red LED chip, designed for applications requiring high reliability, efficient thermal management, and consistent optical performance. The ceramic substrate offers superior thermal conductivity compared to standard plastic packages, making this LED suitable for demanding environments and high-current operation.

The core advantage of this product lies in its robust construction and standardized performance parameters. The target markets include automotive lighting (interior/signal), industrial indicator lights, architectural accent lighting, and any application where a reliable, high-brightness red light source is required in a compact form factor.

2. Technical Parameter Deep Dive

2.1 Absolute Maximum Ratings

The following parameters define the limits beyond which permanent damage to the LED may occur. Operation under these conditions is not guaranteed.

• Forward Current (IF): 500 mA (DC)
• Forward Pulse Current (IFP): 700 mA (Pulse width ≤10ms, Duty cycle ≤1/10)
• Power Dissipation (PD): 1300 mW
• Operating Temperature (Topr): -40°C to +100°C
• Storage Temperature (Tstg): -40°C to +100°C
• Junction Temperature (Tj): 125°C
• Soldering Temperature (Tsld): Reflow soldering at 230°C or 260°C for a maximum of 10 seconds.

2.2 Electro-Optical Characteristics (Typical @ Ta=25°C)

These are the typical performance parameters measured under standard test conditions.

• Forward Voltage (VF): 2.2 V (Typical), 2.6 V (Maximum) at IF=350mA
• Reverse Voltage (VR): 5 V
• Peak Wavelength (λd): 625 nm
• Reverse Current (IR): 50 μA (Maximum)
• Viewing Angle (2θ1/2): 120°

3. Binning System Explanation

To ensure color and brightness consistency in production, LEDs are sorted into performance bins. This allows designers to select parts that meet specific application requirements.

3.1 Luminous Flux Binning (at 350mA)

LEDs are categorized based on their minimum and typical luminous flux output.

• Code 1M: Min 35 lm, Typ 40 lm
• Code 1N: Min 40 lm, Typ 45 lm
• Code 1P: Min 45 lm, Typ 50 lm
• Code 1Q: Min 50 lm, Typ 55 lm

Note: Luminous flux measurement tolerance is ±7%.

3.2 Forward Voltage Binning

LEDs are also binned by their forward voltage drop at the test current.

• Code C: 1.8V - 2.0V
• Code D: 2.0V - 2.2V
• Code E: 2.2V - 2.4V
• Code F: 2.4V - 2.6V

Note: Forward voltage measurement tolerance is ±0.08V.

3.3 Dominant Wavelength Binning

This binning ensures the color hue of the red light is within a specified range.

• Code R1: 620 nm - 625 nm
• Code R2: 625 nm - 630 nm

4. Performance Curve Analysis

The following characteristic graphs, derived from the datasheet, illustrate the LED's behavior under various conditions. These are crucial for circuit design and thermal management.

4.1 Forward Current vs. Forward Voltage (IV Curve)

This graph shows the relationship between the current flowing through the LED and the voltage across it. It is non-linear, typical of a diode. The curve is essential for designing the current-limiting driver circuit. The "knee" voltage is around the typical VF of 2.2V. Operating significantly above the rated current causes a rapid increase in voltage and heat generation.

4.2 Forward Current vs. Relative Luminous Flux

This graph demonstrates how light output changes with drive current. Initially, light output increases nearly linearly with current. However, at higher currents, efficiency droop occurs due to increased junction temperature and other semiconductor effects. For optimal efficiency and lifetime, driving at or below the recommended 350mA is advised, even though the maximum DC current is 500mA.

4.3 Junction Temperature vs. Relative Spectral Power

This curve is critical for understanding color shift and output degradation with temperature. As the LED's junction temperature (Tj) rises, the overall light output decreases. Furthermore, for some semiconductor materials, the peak wavelength can shift slightly, affecting the perceived color. The ceramic package helps mitigate this by dissipating heat more effectively, keeping Tj lower for a given drive current.

4.4 Spectral Power Distribution

This graph plots the intensity of light emitted across different wavelengths. For this red LED, it shows a relatively narrow peak centered around the dominant wavelength (e.g., 625nm). The full width at half maximum (FWHM) of this peak determines the color purity. A narrower peak indicates a more saturated, pure red color.

5. Mechanical & Packaging Information

5.1 Physical Dimensions & Outline Drawing

The LED is housed in a ceramic 3535 surface-mount device (SMD) package. The "3535" designation typically refers to a body size of approximately 3.5mm x 3.5mm. The exact dimensional drawing in the datasheet provides critical measurements including overall length, width, height, and the position of the optical lens. Tolerances are specified as ±0.10mm for .X dimensions and ±0.05mm for .XX dimensions.

5.2 Recommended Pad Layout & Stencil Design

The datasheet provides a recommended footprint for PCB design. This includes the solder pad dimensions and spacing, which are crucial for achieving a reliable solder joint and proper alignment during reflow. An accompanying stencil design guide recommends the aperture size and shape for solder paste application to ensure the correct volume of paste is deposited, preventing solder bridges or insufficient solder.

5.3 Polarity Identification

The LED is a polarized component. The datasheet indicates the anode and cathode terminals. Typically, this is marked on the device itself (e.g., a notch, a dot, or a green marking on the cathode side) and corresponds to the pad layout diagram. Correct polarity is essential for operation.

6. Soldering & Assembly Guidelines

6.1 Reflow Soldering Profile

The LED is compatible with standard infrared or convection reflow soldering processes. The maximum permissible soldering temperature is 260°C for 10 seconds. It is critical to follow a controlled temperature profile with preheat, soak, reflow, and cooling stages to avoid thermal shock, which can crack the ceramic package or damage the internal die and wire bonds.

6.2 Handling & Storage Precautions

LEDs are sensitive to electrostatic discharge (ESD). They should be handled in an ESD-protected environment using grounded wrist straps and conductive mats. The devices should be stored in their original moisture-barrier bags with desiccant in a controlled environment (specified as -40°C to +100°C). If the packaging has been opened, bake-out procedures may be required before reflow if the devices have absorbed moisture.

7. Packaging & Ordering Information

7.1 Tape and Reel Specification

The LEDs are supplied on embossed carrier tape wound onto reels, suitable for automated pick-and-place assembly equipment. The datasheet provides detailed dimensions for the carrier tape pocket, pitch, and reel size. This standardization ensures compatibility with standard SMD assembly feeders.

7.2 Model Number Naming Convention

The product model (e.g., T1901PRA) follows a structured code that encapsulates key features:

• Series/Shape Code ("19"): Denotes the ceramic 3535 package.
• Optics Code ("01"): Indicates the presence of a primary lens.
• Chip Configuration ("P"): Signifies a single high-power (1W) die.
• Color Code ("R"): Represents Red emission.
• Additional Codes ("A\

  LED Specification Terminology

  Complete explanation of LED technical terms

  Photoelectric Performance

  Term	Unit/Representation	Simple Explanation	Why Important
  Luminous Efficacy	lm/W (lumens per watt)	Light output per watt of electricity, higher means more energy efficient.	Directly determines energy efficiency grade and electricity cost.
  Luminous Flux	lm (lumens)	Total light emitted by source, commonly called "brightness".	Determines if the light is bright enough.
  Viewing Angle	° (degrees), e.g., 120°	Angle where light intensity drops to half, determines beam width.	Affects illumination range and uniformity.
  CCT (Color Temperature)	K (Kelvin), e.g., 2700K/6500K	Warmth/coolness of light, lower values yellowish/warm, higher whitish/cool.	Determines lighting atmosphere and suitable scenarios.
  CRI / Ra	Unitless, 0–100	Ability to render object colors accurately, Ra≥80 is good.	Affects color authenticity, used in high-demand places like malls, museums.
  SDCM	MacAdam ellipse steps, e.g., "5-step"	Color consistency metric, smaller steps mean more consistent color.	Ensures uniform color across same batch of LEDs.
  Dominant Wavelength	nm (nanometers), e.g., 620nm (red)	Wavelength corresponding to color of colored LEDs.	Determines hue of red, yellow, green monochrome LEDs.
  Spectral Distribution	Wavelength vs intensity curve	Shows intensity distribution across wavelengths.	Affects color rendering and quality.

  Electrical Parameters

  Term	Symbol	Simple Explanation	Design Considerations
  Forward Voltage	Vf	Minimum voltage to turn on LED, like "starting threshold".	Driver voltage must be ≥Vf, voltages add up for series LEDs.
  Forward Current	If	Current value for normal LED operation.	Usually constant current drive, current determines brightness & lifespan.
  Max Pulse Current	Ifp	Peak current tolerable for short periods, used for dimming or flashing.	Pulse width & duty cycle must be strictly controlled to avoid damage.
  Reverse Voltage	Vr	Max reverse voltage LED can withstand, beyond may cause breakdown.	Circuit must prevent reverse connection or voltage spikes.
  Thermal Resistance	Rth (°C/W)	Resistance to heat transfer from chip to solder, lower is better.	High thermal resistance requires stronger heat dissipation.
  ESD Immunity	V (HBM), e.g., 1000V	Ability to withstand electrostatic discharge, higher means less vulnerable.	Anti-static measures needed in production, especially for sensitive LEDs.

  Thermal Management & Reliability

  Term	Key Metric	Simple Explanation	Impact
  Junction Temperature	Tj (°C)	Actual operating temperature inside LED chip.	Every 10°C reduction may double lifespan; too high causes light decay, color shift.
  Lumen Depreciation	L70 / L80 (hours)	Time for brightness to drop to 70% or 80% of initial.	Directly defines LED "service life".
  Lumen Maintenance	% (e.g., 70%)	Percentage of brightness retained after time.	Indicates brightness retention over long-term use.
  Color Shift	Δu′v′ or MacAdam ellipse	Degree of color change during use.	Affects color consistency in lighting scenes.
  Thermal Aging	Material degradation	Deterioration due to long-term high temperature.	May cause brightness drop, color change, or open-circuit failure.

  Packaging & Materials

  Term	Common Types	Simple Explanation	Features & Applications
  Package Type	EMC, PPA, Ceramic	Housing material protecting chip, providing optical/thermal interface.	EMC: good heat resistance, low cost; Ceramic: better heat dissipation, longer life.
  Chip Structure	Front, Flip Chip	Chip electrode arrangement.	Flip chip: better heat dissipation, higher efficacy, for high-power.
  Phosphor Coating	YAG, Silicate, Nitride	Covers blue chip, converts some to yellow/red, mixes to white.	Different phosphors affect efficacy, CCT, and CRI.
  Lens/Optics	Flat, Microlens, TIR	Optical structure on surface controlling light distribution.	Determines viewing angle and light distribution curve.

  Quality Control & Binning

  Term	Binning Content	Simple Explanation	Purpose
  Luminous Flux Bin	Code e.g., 2G, 2H	Grouped by brightness, each group has min/max lumen values.	Ensures uniform brightness in same batch.
  Voltage Bin	Code e.g., 6W, 6X	Grouped by forward voltage range.	Facilitates driver matching, improves system efficiency.
  Color Bin	5-step MacAdam ellipse	Grouped by color coordinates, ensuring tight range.	Guarantees color consistency, avoids uneven color within fixture.
  CCT Bin	2700K, 3000K etc.	Grouped by CCT, each has corresponding coordinate range.	Meets different scene CCT requirements.

  Testing & Certification

  Term	Standard/Test	Simple Explanation	Significance
  LM-80	Lumen maintenance test	Long-term lighting at constant temperature, recording brightness decay.	Used to estimate LED life (with TM-21).
  TM-21	Life estimation standard	Estimates life under actual conditions based on LM-80 data.	Provides scientific life prediction.
  IESNA	Illuminating Engineering Society	Covers optical, electrical, thermal test methods.	Industry-recognized test basis.
  RoHS / REACH	Environmental certification	Ensures no harmful substances (lead, mercury).	Market access requirement internationally.
  ENERGY STAR / DLC	Energy efficiency certification	Energy efficiency and performance certification for lighting.	Used in government procurement, subsidy programs, enhances competitiveness.