Vishay Semiconductor Opto Division TLHK44R1S2

Overview

TLHK44R1S2 from Vishay Semiconductors is a high-intensity red AlInGaP-on-GaAs LED in a 3 mm tinted diffused T-1 package, delivering 112–280 mcd luminous intensity at 20 mA, with dominant wavelength 630 nm, ±30° viewing angle, and forward voltage 1.9–2.6 V. It serves as a status or indicator light in industrial control panels requiring uniform brightness and wide-angle visibility.

For engineers reviewing the TLHK44R1S2 datasheet, TLHK44R1S2 pinout, TLHK44R1S2 application, or TLHK44R1S2 equivalent, key selection factors include luminous intensity binning (R/S groups), DC and pulsed current capability (30 mA DC / 100 mA surge), thermal resistance (400 K/W), and compatibility with standard 3 mm LED mounting footprints.

Technical Context

The TLHK44R1S2 uses AlInGaP epitaxial structure grown on GaAs substrate to achieve high red luminous efficacy and stable spectral output. Its diffused lens provides ±30° half-intensity angle and uniform angular intensity distribution across the viewing cone.

Designed for DC bias and short-pulse operation, it supports forward currents up to 30 mA continuously (T_amb ≤ 60 °C) and 100 mA surge (t_p ≤ 10 μs), with junction temperature limited to 100 °C and thermal resistance of 400 K/W enabling reliable operation in compact enclosures.

Key Specifications

Pinout & Package

TLHK44R1S2 is housed in a standard Ø3 mm (T-1) plastic package with axial leads: anode (longer lead) and cathode (shorter lead, flat side on housing). The package features a tinted diffused lens, spherical dome (R1.4), and mechanical tolerances per DIN drawing 6.544-5255.01-4.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLHK44R1S2, TLHR4400 offers higher on-axis intensity but narrower viewing angle, while SSL-LX3033SRD provides similar diffusion and binning but requires additional thermal design margin due to 12.5% higher junction-to-ambient resistance.

Availability

TLHK44R1S2 is available at Aetrix Electronics and suitable for industrial HMIs, medical device front panels, and building automation systems requiring stable component supply, consistent luminous intensity grading, and long-term obsolescence management.

Supply support for TLHK44R1S2 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 Intertechnology is a global manufacturer of discrete semiconductors and passive components, founded in 1962 and headquartered in Malvern, PA.

The TLHK44R1S2 belongs to Vishay's standard high-intensity LED product line, engineered specifically for reliability-critical visual indication in industrial, medical, and transportation equipment where consistent color, intensity, and thermal performance are mandatory.

FAQ

What is the luminous intensity range of the TLHK44R1S2 at 20 mA?

The TLHK44R1S2 delivers a luminous intensity range of 112–280 mcd at 20 mA forward current, categorized into R (112–180 mcd) and S (180–280 mcd) intensity groups. This binning ensures consistent visual appearance when multiple TLHK44R1S2 units are deployed on the same interface panel, eliminating visible brightness mismatches.

Does the TLHK44R1S2 support pulsed operation beyond its DC rating?

Yes, the TLHK44R1S2 supports surge forward current up to 100 mA for pulse widths ≤10 μs, as specified in its absolute maximum ratings. This capability enables use in PWM-driven dimming circuits or transient status alerts without exceeding junction temperature limits, provided average power remains within the 80 mW dissipation limit.

What is the viewing angle specification for the TLHK44R1S2?

The TLHK44R1S2 has an angle of half intensity of ±30°, meaning luminous intensity drops to 50% of its on-axis value at 30° off-center in both directions. Its diffused tinted lens produces a near-Lambertian emission pattern, making it ideal for applications requiring broad, uniform illumination across operator-facing surfaces.

Can the TLHK44R1S2 be used in reverse-bias configurations?

The TLHK44R1S2 is rated for 5 V reverse voltage at 10 μA leakage, and the datasheet notes that short-term reverse driving is permissible per Note (1). However, it is not designed for sustained reverse conduction; use is limited to brief AC coupling or diagnostic signal inversion, not continuous reverse-bias operation.

How does the TLHK44R1S2's thermal resistance affect PCB layout?

With a junction-to-ambient thermal resistance of 400 K/W, the TLHK44R1S2 requires careful attention to PCB copper area and airflow in sealed enclosures. To maintain T_j ≤ 100 °C at 30 mA (max 80 mW), keep surrounding traces minimal, avoid thermal islands, and ensure ≥25 mm² of exposed copper connected to cathode/anode pads if ambient exceeds 60 °C.