LTST-T680UGKT Equivalent & Substitute Parts

Part Overview

The LTST-T680UGKT is a green surface mount LED indicator manufactured by Lite-On Inc., featuring a 528nm dominant wavelength and 1255mcd brightness rating in a 2-PLCC package. This part is discontinued at DiGi Electronics, making equivalent substitutes necessary for ongoing production and maintenance applications. The part delivers 3.2V forward voltage at 20mA test current with a 120° viewing angle and clear lens configuration.

Substiute Parts

LTST-T680UGKT

Lite-On Inc.In Stock: 725LTST-T680UGKT Datasheet

Current PartRFQ

LTST-T680UGWT

Lite-On Inc.In Stock: 5096LTST-T680UGWT Datasheet

DirectRFQ

SML-LX2832SUGC-TR

Lumex Opto/Components Inc.In Stock: 37271SML-LX2832SUGC-TR Datasheet

MFR RecommendedRFQ

SML-Z14M4TT86

Rohm SemiconductorIn Stock: 4227SML-Z14M4TT86 Datasheet

MFR RecommendedRFQ

SML-Z14MTT86A

Rohm SemiconductorIn Stock: 3116SML-Z14MTT86A Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LTST-T680UGKT is determined by the following critical parameters:

Primary Compatibility Criteria:

• Color: Green
• Package / Case: 2-PLCC or equivalent surface mount package
• Mounting Type: Surface Mount
• Lens Transparency: Clear (preferred for direct replacement)
• Size / Dimension: 3.20mm L x 2.80mm W (footprint compatibility)
• RoHS Status: ROHS3 Compliant

Secondary Electrical Parameters:

• Voltage - Forward (Vf): 3.2V nominal (acceptable range: 2.0V to 3.2V with circuit design consideration)
• Current - Test: 20mA (acceptable range: 20mA to 50mA)
• Viewing Angle: 120° (acceptable range: 120° or greater)
• Wavelength - Dominant: 528nm (acceptable range: 518nm to 574nm for green indication)

The substitute parts listed below meet the primary compatibility criteria and maintain functional equivalence within the specified electrical parameter ranges.

Parameter Comparison

Engineering Selection Recommendations

LTST-T680UGWT (Lite-On Inc.) This part is the closest direct substitute, sharing identical manufacturer, base product number, color, wavelength, brightness rating, voltage, and current specifications. The primary difference is lens transparency (diffused vs. clear) and package designation (2-LCC J-Lead vs. 2-PLCC). Height is 0.1mm lower. This part is active and maintains full ROHS3 compliance with higher inventory availability (5044 pcs). Select this part when diffused lens characteristics are acceptable for the application.

SML-LX2832SUGC-TR (Lumex Opto/Components Inc.) This part maintains the 2-PLCC package, clear lens, and identical footprint dimensions. However, it operates at significantly lower voltage (2.2V vs. 3.2V) and brightness (150mcd vs. 1255mcd). This part is suitable only for applications where lower brightness is acceptable and circuit design accommodates the reduced forward voltage. Highest inventory availability (37191 pcs) and active product status.

SML-Z14M4TT86 (Rohm Semiconductor) This part operates at 2.1V forward voltage with 224mcd brightness and 50mA test current. The wavelength shifts to 572nm (yellow-green). The 2-PLCC package and clear lens maintain mechanical compatibility. Select this part when the application tolerates lower brightness and altered wavelength characteristics with higher test current requirements.

SML-Z14MTT86A (Rohm Semiconductor) This part operates at the lowest forward voltage (2.0V) with the lowest brightness (90mcd) and 571nm wavelength. The 2-PLCC package and clear lens maintain mechanical compatibility. Moisture sensitivity level is MSL 4 (72 hours) versus MSL 3 (168 hours) for the original part. Select this part only when circuit design requires minimal forward voltage and brightness is not a critical parameter.

All substitute parts maintain ROHS3 compliance, surface mount configuration, and compatible footprint dimensions. Selection depends on specific application requirements for brightness, wavelength, and forward voltage characteristics.

Frequently Asked Questions (FAQ)

Q: Can LTST-T680UGWT replace LTST-T680UGKT directly without circuit modification? A: LTST-T680UGWT shares identical electrical specifications (3.2V, 20mA, 1255mcd) and is manufactured by the same company. The primary difference is lens transparency (diffused vs. clear). Direct substitution is possible if diffused lens characteristics are acceptable. Package designation differs (2-LCC J-Lead vs. 2-PLCC), but footprint dimensions are identical.

Q: Why do the Rohm and Lumex parts have lower forward voltage? A: Different LED chip designs and materials result in different forward voltage characteristics. SML-Z14M4TT86, SML-Z14MTT86A, and SML-LX2832SUGC-TR operate at 2.1V, 2.0V, and 2.2V respectively. Circuit design must accommodate these lower voltages through resistor or current-limiting adjustments.

Q: What is the impact of brightness differences between substitute parts? A: The original LTST-T680UGKT provides 1255mcd brightness. Substitute parts range from 90mcd to 224mcd. Lower brightness may affect visibility in high-ambient-light environments. Application requirements determine acceptable brightness levels.

Q: Are all substitute parts ROHS3 compliant? A: Yes. All listed substitute parts maintain ROHS3 compliance. Moisture sensitivity levels vary: LTST-T680UGKT, LTST-T680UGWT, SML-LX2832SUGC-TR, and SML-Z14M4TT86 are MSL 3 (168 hours); SML-Z14MTT86A is MSL 4 (72 hours).

Q: Do footprint dimensions match across all substitute parts? A: Yes. All substitute parts maintain 3.20mm L x 2.80mm W footprint dimensions. Height varies slightly: LTST-T680UGKT (2.00mm), LTST-T680UGWT (1.90mm), SML-LX2832SUGC-TR (2.10mm), SML-Z14M4TT86 (2.05mm), SML-Z14MTT86A (2.05mm). These variations are within typical PCB assembly tolerances.

Q: Which substitute part has the best inventory availability? A: SML-LX2832SUGC-TR has the highest inventory (37191 pcs), followed by LTST-T680UGWT (5044 pcs), SML-Z14M4TT86 (4140 pcs), and SML-Z14MTT86A (3022 pcs).

Q: Can I use SML-LX2832SUGC-TR as a direct replacement? A: SML-LX2832SUGC-TR maintains package and footprint compatibility but operates at 2.2V with only 150mcd brightness. Circuit design must be modified to accommodate the lower forward voltage. This part is suitable only when reduced brightness is acceptable.