VLMD31L2P1-GS18 Equivalent & Substitute Parts

Part Overview

The VLMD31L2P1-GS18 is a red LED indication component manufactured by Vishay Semiconductor Opto Division, configured as a 2-SMD, J-Lead surface mount device. This part operates at 1.8V forward voltage with a dominant wavelength of 648nm and delivers 35mcd luminous intensity. The VLMD31L2P1-GS18 is classified as obsolete, making identification of active equivalent parts essential for ongoing production and design continuity. Substitute parts must maintain electrical compatibility across forward voltage, current ratings, and optical characteristics while meeting the same mechanical and environmental specifications.

Substiute Parts

VLMD31L2P1-GS18

Vishay Semiconductor Opto DivisionIn Stock: 1090VLMD31L2P1-GS18 Datasheet

Current PartRFQ

VLMD31M2P1-GS08

Vishay Semiconductor Opto DivisionIn Stock: 3118VLMD31M2P1-GS08 Datasheet

Parametric EquivalentRFQ

VLMK3102-GS08

Vishay Semiconductor Opto DivisionIn Stock: 18835VLMK3102-GS08 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the VLMD31L2P1-GS18 is determined by the following critical parameters:

Electrical Compatibility: Forward voltage (Vf), test current, and wavelength characteristics must remain within acceptable operational ranges for the application circuit.

Mechanical Compatibility: Package type (2-SMD, J-Lead), physical dimensions (3.00mm L x 2.80mm W, 1.85mm max height), lens style (Round with Flat Top), and lens size (2.40mm Dia) must match to ensure PCB footprint and assembly compatibility.

Optical Compatibility: Color (Red), dominant wavelength (648nm), and luminous intensity (35mcd) define the visual indication performance.

Environmental & Compliance: RoHS3 compliance, MSL rating (2A, 4 Weeks), and REACH status must be maintained.

Two substitute parts meet these criteria:

VLMD31M2P1-GS08: Active product with identical electrical specifications (1.8V Vf, 10mA test current, 648nm dominant wavelength) and mechanical dimensions. Luminous intensity is 39mcd, representing a 4mcd increase. Packaging differs only in format (Tape & Reel vs. standard packaging).

VLMK3102-GS08: Active product with similar mechanical and optical characteristics but operates at 1.9V forward voltage (0.1V higher) and features a 630nm dominant wavelength (18nm shorter). Luminous intensity matches at 39mcd. This part represents a wavelength variant within the red LED spectrum.

Parameter Comparison

Engineering Selection Recommendations

VLMD31M2P1-GS08 is the primary substitute for VLMD31L2P1-GS18. This part maintains identical electrical specifications (1.8V forward voltage, 10mA test current) and optical wavelength (648nm dominant). The 4mcd increase in luminous intensity (39mcd vs. 35mcd) represents improved brightness performance. Both parts share the same mechanical footprint and environmental compliance ratings. The transition from obsolete to active product status ensures long-term supply availability. Packaging format differs (Tape & Reel), which affects procurement and assembly processes but does not impact electrical or mechanical compatibility.

VLMK3102-GS08 serves as a secondary substitute when wavelength tolerance permits. This part operates at 1.9V forward voltage (0.1V higher than the original) and features a 630nm dominant wavelength (18nm shorter in the red spectrum). The increased forward voltage requires circuit verification to confirm adequate current-limiting resistor performance. The wavelength shift from 648nm to 630nm produces a visually perceptible color difference, shifting from deep red toward pure red. This substitution is appropriate only when the application tolerates both the voltage increase and wavelength variation. Luminous intensity (39mcd) exceeds the original specification.

Both substitutes maintain ROHS3 compliance, MSL 2A (4 Weeks) rating, and identical mechanical dimensions, ensuring PCB compatibility and assembly process continuity.

Frequently Asked Questions (FAQ)

Q: Can VLMD31M2P1-GS08 replace VLMD31L2P1-GS18 without circuit modification?

A: Yes. VLMD31M2P1-GS08 maintains identical forward voltage (1.8V) and test current (10mA) specifications. The 4mcd luminous intensity increase does not require circuit changes. Packaging format differs (Tape & Reel), affecting procurement logistics but not electrical performance.

Q: What is the key difference between VLMD31M2P1-GS08 and VLMK3102-GS08?

A: VLMD31M2P1-GS08 matches the original wavelength (648nm) and forward voltage (1.8V). VLMK3102-GS08 operates at 1.9V forward voltage and 630nm dominant wavelength. The voltage increase requires circuit verification; the wavelength shift produces a visually different red color.

Q: Are both substitutes mechanically compatible with the original PCB footprint?

A: Yes. Both substitutes share identical package type (2-SMD, J-Lead), physical dimensions (3.00mm L x 2.80mm W), and maximum height (1.85mm). PCB footprint and assembly processes remain unchanged.

Q: Do the substitutes maintain the same environmental compliance ratings?

A: Yes. Both VLMD31M2P1-GS08 and VLMK3102-GS08 are ROHS3 compliant with MSL 2A (4 Weeks) rating, matching the original part's environmental specifications.

Q: Why is VLMD31L2P1-GS18 classified as obsolete?

A: Obsolete status indicates the manufacturer has discontinued production. VLMD31M2P1-GS08 and VLMK3102-GS08 are active products with confirmed ongoing availability, making them suitable for design transitions and production continuity.

Q: Can VLMK3102-GS08 be used if the application requires 648nm wavelength?

A: No. VLMK3102-GS08 operates at 630nm dominant wavelength, which is 18nm shorter. This produces a visually distinct color shift. Use only if the application tolerates wavelength variation within the red spectrum.

Q: What is the impact of the 0.1V forward voltage difference in VLMK3102-GS08?

A: The 1.9V forward voltage (vs. 1.8V original) requires verification of the current-limiting resistor value to ensure proper LED current. Circuit simulation or testing is necessary to confirm adequate brightness and component stress levels.