LTST-S320CKT Equivalent & Substitute Parts

Part Overview

The LTST-S320CKT is a red LED indication component manufactured by Lite-On Inc., designed for surface mount, right-angle applications. This 2-SMD, no-lead discrete LED operates at 1.8V forward voltage with a dominant wavelength of 638nm and produces 16 millicandela at 20mA test current. The component is classified as obsolete, necessitating identification of active substitute parts that maintain functional compatibility within specified electrical and mechanical parameters.

Substiute Parts

LTST-S320CKT

Lite-On Inc.In Stock: 706LTST-S320CKT Datasheet

Current PartRFQ

LTST-S320KDKT

Lite-On Inc.In Stock: 985LTST-S320KDKT Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LTST-S320CKT are identified based on the following critical parameters that determine functional and mechanical compatibility:

Electrical Compatibility Criteria:

• Color: Red
• Wavelength - Dominant: 638nm (±tolerance range)
• Current - Test: 20mA
• Viewing Angle: 130°

Mechanical Compatibility Criteria:

• Mounting Type: Surface Mount
• Package / Case: 2-SMD, No Lead
• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level: 3 (168 Hours)

Acceptable Variation Parameters:

• Voltage - Forward (Vf): Tolerance within circuit design limits
• Millicandela Rating: Higher ratings acceptable for indication applications
• Lens Style: Alternative geometries acceptable if optical requirements met
• Height (Max): Variation acceptable within PCB layout constraints
• Product Status: Active parts preferred for obsolete components

The LTST-S320KDKT qualifies as a substitute based on matching dominant wavelength (638nm), test current (20mA), viewing angle (130°), surface mount configuration, 2-SMD no-lead package, and identical RoHS and MSL compliance.

Parameter Comparison

Engineering Selection Recommendations

LTST-S320KDKT as Primary Substitute:

The LTST-S320KDKT is an active product from the same manufacturer (Lite-On Inc.) and maintains critical electrical parameters: identical dominant wavelength (638nm), matching test current (20mA), and equivalent viewing angle (130°). Both components are ROHS3 compliant and share identical MSL classification (3, 168 Hours), ensuring equivalent handling and storage requirements.

The substitute exhibits a forward voltage increase of 0.2V (from 1.8V to 2V) and higher luminous intensity (28.15mcd versus 16mcd). These characteristics are acceptable for indication applications where the circuit design accommodates the voltage differential and increased brightness is not detrimental.

Mechanical differences include reduced width (1.00mm versus 2.00mm) and increased height (2.10mm versus 1.10mm). PCB layout verification is required to confirm clearance compatibility, particularly regarding height constraints and right-angle mounting orientation.

The active product status of LTST-S320KDKT provides supply chain continuity and eliminates obsolescence risk associated with the LTST-S320CKT.

Frequently Asked Questions (FAQ)

Q: Can the LTST-S320KDKT directly replace the LTST-S320CKT without circuit modification?

A: The substitute operates at 2V forward voltage compared to the original 1.8V. Circuit designs must accommodate this 0.2V increase. Verify that current-limiting resistor values and power supply specifications support the higher forward voltage. No other circuit modifications are required for indication applications.

Q: What are the mechanical constraints for substitution?

A: The LTST-S320KDKT has reduced width (1.00mm versus 2.00mm) and increased height (2.10mm versus 1.10mm). Verify PCB layout clearance, particularly vertical space above the component and horizontal routing constraints. The mounting type differs slightly (Surface Mount versus Surface Mount, Right Angle), requiring confirmation that the PCB footprint accommodates the substitute geometry.

Q: Are the optical characteristics equivalent?

A: Both components share identical dominant wavelength (638nm), viewing angle (130°), and lens transparency (clear, colorless). The substitute produces higher luminous intensity (28.15mcd versus 16mcd). For indication applications, this increased brightness is typically acceptable and may improve visibility. Verify that the application does not require the specific lower brightness of the original component.

Q: Do both components have identical compliance certifications?

A: Yes. Both the LTST-S320CKT and LTST-S320KDKT are ROHS3 compliant and classified as MSL 3 (168 Hours). Handling, storage, and reflow requirements are identical.

Q: Why is the LTST-S320KDKT preferred over the obsolete LTST-S320CKT?

A: The LTST-S320KDKT maintains active product status, ensuring long-term supply availability and eliminating obsolescence risk. It meets all critical electrical and optical parameters while providing equivalent compliance certifications.