Vishay Semiconductor Opto Division VLMKE3401-GS18

Overview

VLMKE3401-GS18 from Vishay Semiconductors is a surface-mount bicolor LED in PLCC-4 package integrating red (630 nm dominant wavelength) and yellow (588 nm typical dominant wavelength) AlInGaP-on-GaAs chips, delivering 71–140 mcd red and 112–224 mcd yellow luminous intensity at 20 mA, with ±60° viewing angle - used for dual-color status indication in telecom and office equipment.

For engineers reviewing the VLMKE3401-GS18 datasheet, VLMKE3401-GS18 pinout, VLMKE3401-GS18 application, or VLMKE3401-GS18 equivalent, key selection criteria include luminous intensity binning (R1 group for both colors), JEDEC Level 4 moisture sensitivity, non-diffused lens for light-pipe coupling, IR-reflow compatibility, and PLCC-4 footprint with 2.6 mm × 1.6 mm body size.

Technical Context

This device integrates two monolithic AlInGaP-on-GaAs die in a single white thermoplastic PLCC-4 package with internal reflector and clear epoxy lens. Each chip operates independently with separate anode/cathode terminals, enabling independent red/yellow activation or simultaneous dual-color output.

It supports standard SMT assembly processes including lead-free IR reflow (J-STD-020 compliant) and TTW soldering, with thermal resistance junction-to-ambient of 560 K/W on ≥16 mm² PCB pad. The non-diffused lens provides high directionality ideal for backlighting and optical coupling applications.

Key Specifications

Pinout & Package

PLCC-4 package with 4 terminals: two anodes (A_R, A_Y) and two cathodes (K_R, K_Y) arranged in common-cathode or common-anode configuration depending on PCB layout. Body dimensions: 2.6 mm × 1.6 mm × 1.2 mm height; mounting pad layout optimized for thermal dissipation on ≥16 mm² copper area.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bicolor LED applications.

Compared with VLMKE3401-GS18, VLMKE3400-GS18 offers broader intensity tolerance at lower cost but sacrifices color-matched brightness uniformity, while TLDR6300 provides different chromaticity and voltage characteristics incompatible with red/yellow signaling systems.

Availability

VLMKE3401-GS18 is available at Aetrix Electronics and suitable for telecom indicator systems, office equipment backlighting, and LCD symbol illumination requiring stable component supply, moisture-sensitive handling support, and consistent PLCC-4 SMT logistics.

Supply support for VLMKE3401-GS18 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Vishay Semiconductors is a global manufacturer of discrete semiconductors and passive components, specializing in high-reliability optoelectronics, power MOSFETs, and precision resistors.

The VLMKE3400/VLMKE3401 series was designed specifically for compact, high-brightness bicolor status indication in space-constrained consumer and industrial interfaces using AlInGaP technology for stable red/yellow output.

FAQ

What is the maximum continuous forward current rating for each die in the VLMKE3401-GS18?

The VLMKE3401-GS18 has a maximum DC forward current of 30 mA per diode at ambient temperatures ≤80 °C. This limit applies independently to both the red and yellow chips. Exceeding 30 mA risks accelerated degradation and thermal runaway, especially under poor PCB heat sinking conditions. The VLMKE3401-GS18 must be operated within this specification to maintain its rated luminous intensity and 100,000-hour lifetime.

Does the VLMKE3401-GS18 support lead-free reflow soldering, and what profile should be used?

Yes, the VLMKE3401-GS18 is qualified for lead-free IR reflow soldering per J-STD-020, with a peak temperature of 245 °C (maximum 260 °C for ≤30 s). The recommended profile includes preconditioning per JEDEC Level 4, ramp-up ≤3 °C/s, time above 217 °C of 60–150 s, and ramp-down ≤6 °C/s. The VLMKE3401-GS18 must be stored and handled per moisture sensitivity level 4 requirements prior to reflow.

How is luminous intensity binned for the VLMKE3401-GS18, and what does "R1" mean?

The VLMKE3401-GS18 is binned into the R1 luminous intensity group: 112–140 mcd for yellow and 71–140 mcd for red at 20 mA. This binning ensures tight brightness matching within each reel - no mixing of intensity groups occurs. The "R1" designation guarantees that every VLMKE3401-GS18 unit shipped shares this intensity range, critical for consistent visual appearance in multi-LED arrays.

Can the red and yellow chips in the VLMKE3401-GS18 be driven simultaneously, and what is the impact on forward voltage?

Yes, both chips in the VLMKE3401-GS18 can be driven simultaneously using independent current paths. Forward voltage remains unchanged: red operates at 1.9–2.6 V and yellow at 2.0–2.6 V at 20 mA. Simultaneous operation does not cause voltage stacking or interaction because the dies share no internal electrical connection - the VLMKE3401-GS18 behaves electrically as two isolated diodes in one package.

What is the thermal resistance junction-to-ambient for the VLMKE3401-GS18, and how does PCB layout affect it?

The VLMKE3401-GS18 has a thermal resistance junction-to-ambient (R_thJA) of 560 K/W when mounted on a PCB with copper pad area >16 mm². Reducing pad size below this threshold increases R_thJA nonlinearly - e.g., a 4 mm² pad raises it to ~1200 K/W, risking junction temperatures exceeding 125 °C at 30 mA. Proper thermal design is essential for maintaining VLMKE3401-GS18 reliability and luminous output stability over time.