Vishay Semiconductor Opto Division TLHR4401

Overview

TLHR4401 from Vishay Semiconductors is a red light-emitting diode (LED) in a 3 mm tinted diffused plastic package (T-1), delivering 2.5–14 mcd luminous intensity at 10 mA, with dominant wavelength 612–625 nm and ±30° viewing angle. It serves as an on/off indicator or status light in industrial control panels and consumer appliance interfaces.

For engineers reviewing the TLHR4401 datasheet, TLHR4401 pinout, TLHR4401 application, or TLHR4401 equivalent, key selection criteria include luminous intensity binning (Group N), forward voltage range (2–3 V @ 20 mA), reverse voltage rating (6 V), junction temperature limit (100 °C), and compatibility with DC or pulsed drive up to 1 A surge current.

Technical Context

The TLHR4401 uses GaAsP-on-GaP epitaxial technology to achieve stable red emission with high on-off contrast. Its 3 mm tinted diffused lens provides uniform illumination and wide angular distribution (±30° half-intensity angle), optimized for human-visible status indication rather than collimated signaling.

It operates within -40 to +100 °C ambient temperature range and supports continuous DC bias or short-pulse operation (tp ≤ 10 μs, IFSM = 1 A). Thermal resistance junction-to-ambient is 400 K/W, requiring minimal heatsinking in typical panel-mount applications.

Key Specifications

Pinout & Package

TLHR4401 is a two-terminal through-hole LED in a standard Ø 3 mm (T-1) tinted diffused plastic package with axial leads. Cathode is identified by flat side on lens housing and shorter lead per Vishay mechanical 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 TLHR4401, TLHR4400 offers lower cost and adequate brightness for dim environments, while TLHR4405 provides superior visibility in bright conditions but requires attention to thermal management and may exceed required intensity in standard indoor use.

Availability

TLHR4401 is available at Aetrix Electronics and suitable for industrial control panels, consumer appliance interfaces, and test equipment maintenance lighting requiring stable component supply and consistent luminous intensity binning.

Supply support for TLHR4401 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 TLHR4401 belongs to Vishay's standard 3 mm LED product line, designed specifically for general-purpose indicating and status lighting where consistent color, wide viewing angle, and mechanical robustness are prioritized over ultra-high efficiency or narrow spectral bandwidth.

FAQ

What is the luminous intensity range of TLHR4401 and how is it binned?

The TLHR4401 has a luminous intensity range of 2.5–14 mcd at 10 mA and is categorized in Group N (2.5–5 mcd) per Vishay's intensity classification table. Units shipped in one packing unit maintain IVmin/IVmax ≤ 0.5, ensuring consistent brightness across the batch. This binning supports uniform appearance in multi-LED arrays without manual sorting. TLHR4401 is tested per the standard 25 ms pulse method defined in the datasheet.

What is the correct polarity and physical identification for TLHR4401 leads?

The TLHR4401 has two axial leads: the anode is the longer lead, and the cathode is the shorter lead, marked by a flat edge on the lens housing. Per Vishay mechanical drawing 6.544-5255.01-4, this orientation follows Code 12 (cathode before anode in tape feed). Incorrect polarity results in no emission and risks exceeding the 6 V reverse voltage rating, potentially degrading reliability. Always verify orientation before soldering TLHR4401.

Can TLHR4401 be driven with pulsed current, and what are the limits?

Yes, TLHR4401 supports pulsed operation with a surge forward current (IFSM) of 1 A for pulse widths ≤ 10 μs, provided duty cycle and average power remain within ratings. The absolute maximum DC forward current is 30 mA, and power dissipation must stay ≤ 100 mW at Tamb ≤ 60 °C. Pulse drive enables multiplexed display designs while maintaining brightness; thermal design must account for peak junction temperature rise during pulses. TLHR4401 performance under pulsing is documented in Figures 2 and 6 of the datasheet.

What is the dominant wavelength specification for TLHR4401 and why does it matter?

The dominant wavelength of TLHR4401 is specified as 612–625 nm, placing its red emission in the high-visibility portion of the human photopic response curve. This range ensures strong contrast against neutral backgrounds and compatibility with red-filtered sensors or human operators expecting standard "traffic-light red." Unlike peak wavelength (635 nm), dominant wavelength reflects perceived color under standard illuminants and is critical for color-matching across batches. TLHR4401 does not include wavelength binning beyond this range.

How does TLHR4401 compare to other parts in the TLHR440x family in terms of forward voltage?

TLHR4401 shares identical forward voltage characteristics with other TLHR440x variants: 2–3 V at 20 mA, with typical value ~2.5 V. This consistency arises from the common GaAsP-on-GaP die technology and package construction. Forward voltage variation is process-controlled and not intensity-binned; therefore, TLHR4401, TLHR4400, and TLHR4405 all exhibit the same VF range. Designers can use the same series resistor calculation across the family when driving at 20 mA, simplifying BOM consolidation. TLHR4401 maintains this behavior across its full operating temperature range (-40 to +100 °C).