LTST-B680QEKT Red LED SMD Equivalent & Substitute Parts

Part Overview

The LTST-B680QEKT is a red surface-mount LED indicator manufactured by LITEON, designed for discrete indication applications. This 2-PLCC package LED operates at 2.2V forward voltage with a 624nm dominant wavelength and delivers 785mcd brightness at 20mA test current. The part is currently active in production and fully compliant with ROHS3 and REACH regulations. Equivalent and substitute parts are identified to support supply chain continuity, design flexibility, and inventory optimization while maintaining functional compatibility within specified electrical and mechanical parameters.

Substiute Parts

LTST-B680QEKT

LITEONIn Stock: 4860LTST-B680QEKT Datasheet

Current PartRFQ

AA3528SESK/J3

KingbrightIn Stock: 24671AA3528SESK/J3 Datasheet

MFR RecommendedRFQ

SML-LX2832SIC-TR

Lumex Opto/Components Inc.In Stock: 2349SML-LX2832SIC-TR Datasheet

MFR RecommendedRFQ

SMTL2-URC

Bivar Inc.In Stock: 15048SMTL2-URC Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LTST-B680QEKT are qualified based on the following critical parameters that determine functional compatibility:

Primary Compatibility Criteria:

• Package / Case: 2-PLCC (mandatory for PCB footprint compatibility)
• Mounting Type: Surface Mount (mandatory for assembly process compatibility)
• Color: Red (mandatory for application requirement)
• Lens Transparency: Clear (mandatory for optical performance)
• Viewing Angle: 120° (acceptable range for indication applications)
• Size / Dimension: 3.20mm L x 2.80mm W (mandatory for PCB layout compatibility)

Electrical Compatibility Criteria:

• Voltage - Forward (Vf): 2.0V to 2.2V (acceptable operating range)
• Current - Test: 20mA (standard test condition)
• Wavelength - Dominant: 624nm to 625nm (red spectrum tolerance)

Regulatory Compliance:

• RoHS3 Compliant (mandatory)
• REACH Unaffected (mandatory)

Three substitute parts meet these criteria with varying brightness levels and forward voltage specifications, enabling selection based on specific circuit requirements and supply availability.

Parameter Comparison

Engineering Selection Recommendations

All four parts maintain active production status and full compliance with ROHS3 and REACH regulations, ensuring regulatory continuity across substitution scenarios.

LTST-B680QEKT (Primary Part): Delivers maximum brightness at 785mcd with 2.2V forward voltage and 1.90mm maximum height. Optimal for applications requiring highest luminous intensity within standard 2-PLCC form factor constraints.

AA3528SESK/J3 (Kingbright): Operates at identical 2.2V forward voltage with 450mcd brightness. Suitable for applications where brightness reduction is acceptable and supply availability of LITEON parts is limited. Maintains MSL 3 rating equivalent to primary part.

SML-LX2832SIC-TR (Lumex Opto/Components Inc.): Operates at reduced 2.0V forward voltage with 250mcd brightness. Applicable in circuits designed for lower forward voltage operation or where minimum brightness requirements are met at 250mcd. Maintains MSL 3 rating.

SMTL2-URC (Bivar Inc.): Operates at lowest forward voltage of 1.9V with 700mcd brightness, providing high luminous intensity at reduced voltage. MSL rating increases to 4 (72 Hours), requiring stricter moisture control during storage and assembly. Suitable for low-voltage circuit designs requiring high brightness output.

Frequently Asked Questions (FAQ)

Q: Can SMTL2-URC replace LTST-B680QEKT in all applications?

A: SMTL2-URC is electrically compatible within the 2-PLCC red LED category but operates at 1.9V forward voltage versus 2.2V for the primary part. Circuit design must accommodate this voltage difference. Additionally, SMTL2-URC carries MSL 4 (72 Hours) versus MSL 3 (168 Hours), requiring more stringent moisture control during component storage and assembly processes.

Q: What is the primary difference between AA3528SESK/J3 and SML-LX2832SIC-TR?

A: Both parts share identical 2-PLCC packaging and 120° viewing angle. The primary differences are forward voltage (2.2V versus 2.0V) and brightness (450mcd versus 250mcd). AA3528SESK/J3 maintains voltage parity with the primary LTST-B680QEKT part, while SML-LX2832SIC-TR operates at lower voltage with reduced brightness output.

Q: Are all substitute parts compatible with existing PCB layouts designed for LTST-B680QEKT?

A: Yes. All substitute parts maintain identical footprint dimensions of 3.20mm L x 2.80mm W and 2-PLCC package specification. Maximum height varies slightly (1.90mm primary versus 2.10mm for substitutes), which is acceptable within standard PCB assembly clearance tolerances for surface-mount components.

Q: Which substitute part offers the closest electrical match to LTST-B680QEKT?

A: AA3528SESK/J3 provides the closest electrical match, maintaining identical 2.2V forward voltage and 20mA test current. The primary difference is brightness at 450mcd versus 785mcd. This part is recommended when voltage-matched operation is a design requirement.

Q: What does MSL 4 (72 Hours) mean for SMTL2-URC compared to MSL 3 (168 Hours)?

A: MSL 4 indicates higher moisture sensitivity, requiring component use within 72 hours of package opening under controlled humidity conditions. MSL 3 allows 168 hours. For SMTL2-URC, stricter moisture control protocols must be implemented during storage, handling, and assembly to prevent moisture-induced failures.

Q: Can brightness differences between substitute parts affect circuit operation?

A: Brightness differences (250mcd to 785mcd range) depend on application requirements. For indicator-only applications, lower brightness may be acceptable. For applications requiring specific luminous intensity thresholds, brightness specifications must be evaluated against circuit design parameters and user visibility requirements.