SMD LED 23-21/R6C-AM1N2AY/2A Datasheet - Size 2.3x2.1mm - Voltage 1.55-2.15V - Color Red (632nm) - Power 60mW - English Technical Document

1. Product Overview

The 23-21 SMD LED is a compact, surface-mount light-emitting diode designed for modern electronic applications requiring reliable indicator lighting or backlighting in constrained spaces. This component represents a significant advancement over traditional lead-frame type LEDs, offering substantial benefits in terms of board real estate, assembly efficiency, and final product size.

1.1 Core Advantages and Product Positioning

The primary advantage of the 23-21 SMD LED lies in its miniature footprint. With dimensions of approximately 2.3mm x 2.1mm, it enables significant reductions in printed circuit board (PCB) size. This directly translates to higher component packing density, allowing for more complex functionality within a smaller overall device profile. The reduced storage space requirements for both the components themselves and the finished assemblies offer logistical and cost benefits. Furthermore, the lightweight nature of the SMD package makes it an ideal candidate for portable and miniature applications where weight is a critical factor, such as in wearable technology, compact consumer electronics, and miniaturized control panels.

The product is positioned as a general-purpose indicator and backlight solution. It is not designed for high-power illumination but rather for status indication, symbolic backlighting, and low-level ambient lighting where consistent color and reliable performance are paramount.

1.2 Key Features Summary

• Packaging: Supplied in 8mm tape on 7-inch diameter reels, compatible with standard automated pick-and-place assembly equipment.
• Process Compatibility: Fully compatible with mainstream infrared (IR) and vapor phase reflow soldering processes.
• Type: Mono-color type, emitting a brilliant red light.
• Environmental Compliance: The product is Pb-free (lead-free), compliant with the RoHS (Restriction of Hazardous Substances) directive, compliant with EU REACH regulations, and meets halogen-free standards (Bromine <900 ppm, Chlorine <900 ppm, Br+Cl < 1500 ppm).

2. Technical Parameters: In-Depth Objective Interpretation

This section provides a detailed, objective analysis of the electrical, optical, and thermal parameters specified in the datasheet. Understanding these limits is crucial for reliable circuit design.

2.1 Absolute Maximum Ratings

The Absolute Maximum Ratings define the stress limits beyond which permanent damage to the device may occur. These are not operating conditions.

• Reverse Voltage (V_R): 5V. Applying a reverse bias voltage exceeding this value can cause junction breakdown.
• Continuous Forward Current (I_F): 25mA. This is the maximum DC current that can be passed through the LED continuously at an ambient temperature (T_a) of 25°C.
• Peak Forward Current (I_FP): 60mA. This higher current is permissible only under pulsed conditions, specifically at a duty cycle of 1/10 and a frequency of 1kHz. It is useful for brief, high-intensity flashes but must not be used for DC operation.
• Power Dissipation (P_d): 60mW. This is the maximum amount of power the device can dissipate as heat. Exceeding this limit, typically by driving with too high a current or at too high an ambient temperature, will raise the junction temperature and degrade performance or cause failure.
• Electrostatic Discharge (ESD): Human Body Model (HBM) 2000V. This rating indicates a moderate level of ESD robustness. Standard ESD handling precautions (use of grounded workstations, wrist straps) are still required during assembly and handling.
• Operating Temperature (T_opr): -40°C to +85°C. The LED is designed to function within this ambient temperature range.
• Storage Temperature (T_stg): -40°C to +90°C.
• Soldering Temperature: The device can withstand reflow soldering with a peak temperature of 260°C for up to 10 seconds, or hand soldering at 350°C for up to 3 seconds per terminal.

2.2 Electro-Optical Characteristics

These parameters are measured at a standard test condition of T_a=25°C and a forward current (I_F) of 5mA, unless otherwise specified. They define the typical performance of the device.

• Luminous Intensity (I_v): Ranges from a minimum of 18.0 mcd to a maximum of 45.0 mcd. The actual value for a specific unit depends on its bin code (see Section 3). A typical value is not stated, implying significant variation across the production spread.
• Viewing Angle (2θ_1/2): 130 degrees. This is the full angle at which the luminous intensity drops to half of its peak value. A 130° angle indicates a relatively wide viewing pattern, suitable for indicators that need to be seen from various angles.
• Peak Wavelength (λ_p): 632 nm (typical). This is the wavelength at which the spectral power output is maximum.
• Dominant Wavelength (λ_d): Ranges from 617.5 nm to 633.5 nm. This wavelength corresponds to the perceived color of the light and is more relevant for colorimetric applications than peak wavelength. The binning system categorizes devices based on this parameter.
• Spectral Bandwidth (Δλ): 20 nm (typical). This is the width of the emitted spectrum at half its maximum power. A value of 20nm is characteristic of AlGaInP-based red LEDs, indicating a relatively pure, saturated red color.
• Forward Voltage (V_F): Ranges from 1.55V to 2.15V at I_F=5mA. This parameter is also binned (see Section 3). The low forward voltage is a key advantage for low-voltage battery-operated circuits.
• Reverse Current (I_R): Maximum of 10 µA at V_R=5V. This specifies the maximum leakage current when the device is reverse-biased.

Note on Tolerances: The datasheet specifies separate tolerances for key parameters: Luminous Intensity (±11%), Dominant Wavelength (±1nm), and Forward Voltage (±0.1V). These tolerances apply on top of the bin ranges and must be considered in the tightest tolerance analysis.

3. Binning System Explanation

To ensure consistency in mass production, LEDs are sorted into performance bins. This allows designers to select parts that meet specific minimum criteria for their application.

3.1 Luminous Intensity Binning

Devices are categorized into four bins (M1, M2, N1, N2) based on their measured luminous intensity at I_F=5mA.

• M1: 18.0 – 22.5 mcd
• M2: 22.5 – 28.5 mcd
• N1: 28.5 – 36.0 mcd
• N2: 36.0 – 45.0 mcd

Selection of a higher bin (e.g., N2) guarantees a brighter LED but may come at a higher cost. For applications where absolute brightness is not critical but consistency across multiple indicators is, specifying a single bin is essential.

3.2 Dominant Wavelength Binning

Color consistency is managed through four wavelength bins (E4, E5, E6, E7). This is crucial for applications where multiple LEDs are used together and must appear identical in color.

• E4: 617.5 – 621.5 nm (more orange-red)
• E5: 621.5 – 625.5 nm
• E6: 625.5 – 629.5 nm
• E7: 629.5 – 633.5 nm (more pure red)

3.3 Forward Voltage Binning

Three voltage bins (00, 0, 1) help in designing efficient current-limiting circuits, especially in parallel LED arrays where voltage matching can improve current sharing.

• 00: 1.55 – 1.75 V
• 0: 1.75 – 1.95 V
• 1: 1.95 – 2.15 V

4. Performance Curve Analysis

While the datasheet references "Typical Electro-Optical Characteristics Curves," the specific graphs are not provided in the text. Based on standard LED behavior and the given parameters, we can infer the likely relationships.

4.1 Inferred Current-Voltage (I-V) Relationship

The forward voltage (V_F) is specified at 5mA. For a typical AlGaInP red LED, the I-V curve is exponential. Operating the LED at a current lower than 5mA will result in a proportionally lower V_F (e.g., ~1.8-2.0V at 2mA). Driving it at the maximum continuous current of 25mA will cause V_F to increase, likely to a value near the upper limit of its bin range or slightly above due to resistive heating in the semiconductor and contacts. A series resistor must always be used to limit the current, as the LED's dynamic resistance is very low and a small increase in voltage causes a large increase in current, risking thermal runaway.

4.2 Luminous Intensity vs. Current (L-I)

Luminous intensity is approximately proportional to forward current in the lower to mid-current range (up to ~20mA for such devices). The rated luminous intensity is at 5mA. Operating at 20mA would typically yield an intensity roughly 3.5 to 4 times higher, but this must be verified against the maximum power dissipation limit (60mW). At 20mA and a V_F of 2.0V, power dissipation is 40mW, which is within the limit at 25°C. However, efficacy (light output per electrical watt) often decreases at higher currents due to increased heat.

4.3 Temperature Dependence

Key parameters are temperature-sensitive:

• Forward Voltage (V_F): Decreases with increasing temperature (negative temperature coefficient, typically -2mV/°C for red LEDs). This can slightly increase current if driven by a constant voltage source with a series resistor.
• Luminous Intensity (I_v): Decreases with increasing junction temperature. The derating can be significant, often around 0.5-1% per °C rise above 25°C. Adequate thermal management on the PCB is necessary to maintain consistent brightness, especially in high ambient temperatures or when driven at higher currents.
• Dominant Wavelength (λ_d): Shifts slightly with temperature, typically at a rate of about 0.1 nm/°C for AlGaInP LEDs.

5. Mechanical and Package Information

5.1 Package Dimensions

The datasheet includes a detailed dimensioned drawing of the 23-21 SMD package. Key features include:

• The overall length is 2.3 mm and width is 2.1 mm (hence the 23-21 designation).
• The package has two anode/cathode terminals on the bottom side for surface mounting.
• A polarity indicator (likely a notch or a green marking on the top or bottom) is present to distinguish the cathode. Correct orientation is critical during assembly.
• The recommended land pattern (footprint) for PCB design is derived from these dimensions, typically including solder pads slightly larger than the device terminals to ensure a reliable solder fillet.
• All unspecified tolerances are ±0.1mm.

6. Soldering and Assembly Guidelines

Adherence to these guidelines is critical for yield and long-term reliability.

6.1 Current Limiting and Protection

Mandatory: An external current-limiting resistor must be used in series with the LED. The LED is a current-driven device. Without a resistor, even a small variation in the supply voltage (e.g., battery voltage drop) can cause a large, potentially destructive, increase in forward current.

6.2 Storage and Moisture Sensitivity

The LEDs are packaged in a moisture-resistant barrier bag with desiccant.

• Before Opening: Store at ≤30°C and ≤90% Relative Humidity (RH).
• After Opening: The "floor life" (time components can be exposed to ambient factory air) is 1 year at ≤30°C and ≤60% RH.
• Rebaking: If the desiccant indicates saturation (color change) or the floor life is exceeded, a rebake is required: 60°C ±5°C for 24 hours before use in a reflow process.

6.3 Reflow Soldering Profile

A lead-free (Pb-free) reflow profile is specified:

• Pre-heating: 150-200°C for 60-120 seconds.
• Time Above Liquidus (TAL): 60-150 seconds above 217°C.
• Peak Temperature: 260°C maximum, held for a maximum of 10 seconds.
• Heating Rate: Maximum 6°C/second.
• Time Above 255°C: Maximum 30 seconds.
• Cooling Rate: Maximum 3°C/second.

Important Restrictions: Reflow soldering should not be performed more than two times. Avoid mechanical stress on the package during heating and do not warp the PCB after soldering.

6.4 Hand Soldering and Rework

Hand soldering is permitted but requires extreme care to avoid thermal damage.

• Use a soldering iron with a tip temperature ≤350°C.
• Limit contact time to ≤3 seconds per terminal.
• Use a low-power iron (≤25W capacity).
• Allow a cooling interval of ≥2 seconds between soldering each terminal.
• Repair/Rework: Not recommended after the LED is soldered. If unavoidable, use a dual-head soldering iron to simultaneously heat both terminals for removal, minimizing stress on the solder joints and the LED's internal connections. Always verify post-rework functionality.

7. Packaging and Ordering Information

7.1 Reel and Tape Specifications

The product is supplied in industry-standard packaging for automated assembly:

• Carrier Tape Width: 8 mm.
• Reel Diameter: 7 inches.
• Quantity per Reel: 2000 pieces.

7.2 Label Information

The reel label contains critical information for traceability and correct application:

• CPN: Customer's Part Number (as assigned by the buyer).
• P/N: Manufacturer's Part Number (23-21/R6C-AM1N2AY/2A).
• QTY: Packing Quantity (2000).
• CAT: Luminous Intensity Rank (e.g., M1, N2).
• HUE: Chromaticity Coordinates & Dominant Wavelength Rank (e.g., E5, E6).
• REF: Forward Voltage Rank (e.g., 00, 1).
• LOT No: Manufacturing Lot Number for traceability.

8. Application Suggestions and Design Considerations

8.1 Typical Application Scenarios

• Automotive Interior: Backlighting for dashboard instruments, switches, and control panels.
• Telecommunications Equipment: Status indicators and keypad backlighting in telephones, fax machines, and networking hardware.
• Consumer Electronics: Flat backlighting for small LCD displays, backlighting for membrane switches and symbols on remote controls, appliances, and audio equipment.
• General Indication: Power status, mode indication, and alert signals in a wide variety of electronic devices.

8.2 Critical Design Considerations

1. Current Drive Circuit: Always use a series resistor. Calculate the resistor value using R = (V_supply - V_F) / I_F. Use the maximum V_F from the bin (e.g., 2.15V) to ensure the current does not exceed the desired level even with the highest-voltage LED.
2. Thermal Management: Although low power, consider the effect of ambient temperature and adjacent heat-generating components. For consistent brightness, avoid operating at the absolute maximum current (25mA) in high-temperature environments (>70°C).
3. Visual Consistency: For applications with multiple LEDs viewed together, specify tight bins for both luminous intensity (CAT) and dominant wavelength (HUE) to ensure uniform appearance.
4. PCB Layout: Follow the recommended land pattern. Ensure the polarity marking on the PCB silkscreen matches the LED's polarity indicator. Provide adequate clearance between the LED and other components.
5. ESD Protection: Implement basic ESD protection on input lines if the LED is directly exposed to user interfaces, or ensure assembly is performed in an ESD-controlled environment.

9. Technical Comparison and Differentiation

The 23-21 SMD LED differentiates itself primarily through its combination of a very small form factor and a well-defined performance specification with a comprehensive binning system.

vs. Larger SMD LEDs (e.g., 3528, 5050): The 23-21 offers a significantly smaller footprint and lower profile, enabling denser PCB layouts and thinner end products. It trades off ultimate light output (lumens) for miniaturization, making it ideal for indicator-level applications rather than area illumination.

vs. Chip LEDs (No Package): The 23-21 provides a robust, handled package with integrated lensing (for the 130° viewing angle) and solderable terminals, simplifying assembly compared to bare die which require specialized mounting and wire bonding.

vs. Through-Hole LEDs: The key advantages are automated assembly compatibility, reduced board space, and the absence of leads that require bending and clipping. This leads to lower assembly cost and higher reliability in high-volume production.

10. Frequently Asked Questions (Based on Technical Parameters)

Q1: Can I drive this LED directly from a 3.3V or 5V logic supply?
A: No. You must always use a series current-limiting resistor. For a 3.3V supply and a target current of 5mA, with a maximum V_F of 2.15V, the minimum resistor value is R = (3.3V - 2.15V) / 0.005A = 230Ω. A standard 240Ω or 270Ω resistor would be appropriate.

Q2: Why is there such a wide range in luminous intensity (18 to 45 mcd)?
A: This reflects natural variation in semiconductor manufacturing. The binning system (M1, M2, N1, N2) allows you to select a minimum brightness level for your design. If your circuit requires at least 25 mcd, you would specify bin N1 or N2.

Q3: Is this LED suitable for outdoor use?
A: The operating temperature range (-40°C to +85°C) suggests it can withstand a wide range of ambient conditions. However, long-term exposure to direct sunlight, moisture, and UV radiation is not covered by the datasheet. For outdoor use, consider additional protective conformal coating on the PCB and verify the resin material's UV stability if not specified.

Q4: What does the "R6C" in the part number likely signify?
A: While not explicitly defined here, in common LED part numbering, "R" often denotes Red color, "6" may relate to the dominant wavelength bin or color code, and "C" could indicate a water-clear resin (as noted in the Device Selection Guide).

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