LTST-E683RGB RGB LED 4-PLCC SMD Equivalent & Substitute Parts

Part Overview

The LTST-E683RGB is a common anode RGB LED in 4-PLCC surface mount package manufactured by Lite-On Inc. This component provides simultaneous red, green, and blue light output for RGB indication applications. The part is currently obsolete, making equivalent substitute components necessary for ongoing production and maintenance requirements. The LTST-E683RGB operates at forward voltages of 2.1V (red), 3.3V (green), and 3.3V (blue) with a 120° viewing angle and clear lens configuration.

Substiute Parts

LTST-E683RGB

Lite-On Inc.In Stock: 3176LTST-E683RGB Datasheet

Current PartRFQ

SMTL4-SRGB

Bivar Inc.In Stock: 26683SMTL4-SRGB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LTST-E683RGB is based on strict alignment of the following electrical and mechanical parameters:

Package compatibility: Both parts must use 4-PLCC surface mount package with identical footprint dimensions (3.20mm L x 2.80mm W).

Configuration: Common anode RGB LED configuration must be maintained for circuit compatibility.

Color output: Red, green, and blue wavelength ranges must support RGB indication functionality.

Electrical characteristics: Forward voltage and test current specifications must be compatible with existing circuit design parameters.

Lens properties: Clear lens with round flat-top style and 120° viewing angle must be preserved.

Physical dimensions: Height and overall package dimensions must fit within existing PCB assembly constraints.

The SMTL4-SRGB from Bivar Inc. meets these substitution criteria while offering active product status and improved availability.

Parameter Comparison

Engineering Selection Recommendations

The SMTL4-SRGB is a direct substitute for the obsolete LTST-E683RGB based on matching package, configuration, and core electrical parameters. The substitute part offers active product status with confirmed availability of 26,635 units in stock, compared to the obsolete status of the original part.

Both parts maintain identical 4-PLCC package dimensions, common anode configuration, and 120° viewing angle. Forward voltage specifications are compatible, with the SMTL4-SRGB operating at 1.9V for red (0.2V lower than the original) while maintaining 3.3V for green and blue channels. Test current remains constant at 20mA across all color channels.

The SMTL4-SRGB demonstrates improved luminous intensity across all color channels, with notably higher green output (1450mcd versus 627.5mcd). Physical height difference is minimal (2.05mm versus 2.00mm), remaining within typical PCB assembly tolerances.

Both parts carry REACH Unaffected status and EAR99 ECCN classification. The SMTL4-SRGB includes ROHS3 compliance certification. Moisture sensitivity level increases from MSL 3 to MSL 4, requiring adjusted storage and handling protocols.

Frequently Asked Questions (FAQ)

Q: Can the SMTL4-SRGB directly replace the LTST-E683RGB without PCB modifications?

A: Yes. Both parts use identical 4-PLCC package footprints with matching pin configurations and common anode topology. No PCB layout changes are required for mechanical and electrical compatibility.

Q: What is the significance of the forward voltage difference (2.1V vs 1.9V for red)?

A: The 0.2V reduction in red forward voltage for the SMTL4-SRGB requires circuit current-limiting resistor recalculation to maintain 20mA test current. Existing resistor values may need adjustment depending on supply voltage and circuit design.

Q: How does the increased millicandela rating affect circuit design?

A: The SMTL4-SRGB provides higher luminous intensity, particularly in the green channel (1450mcd versus 627.5mcd). Existing current-limiting resistors may need adjustment to prevent over-brightness or to maintain consistent color balance in RGB applications.

Q: Are there storage and handling differences between these parts?

A: Yes. The SMTL4-SRGB has MSL 4 rating (72 hours) compared to MSL 3 (168 hours) for the original part. This requires stricter moisture control during storage and shorter time windows between package opening and component placement on the assembly line.

Q: What is the height difference impact on PCB assembly?

A: The 0.05mm height increase (2.05mm versus 2.00mm) is negligible for standard PCB assembly processes and remains within typical component tolerance ranges. No assembly equipment adjustments are necessary.

Q: Are both parts compliant with environmental regulations?

A: Both parts carry REACH Unaffected status. The SMTL4-SRGB includes ROHS3 compliance certification, providing additional environmental compliance documentation for regulated applications.