Bottom Line: Choose a Würth Elektronik 150141-series SMD indicator LED by fixing four decisions in order: the color that the user must recognize, the brightness at the actual drive current, the 3528 top-view package and optical geometry, and the supply configuration you can buy consistently. For a conventional red status channel, 150141RS73100 is the practical starting point because red is immediately understood for fault, stop, alarm, or power-off states and can usually be driven from low-voltage rails with comfortable resistor margin. Do not select from color alone: compare intensity at 20 mA, derate for lower current and temperature, validate visibility behind the real light pipe or enclosure, and source the exact suffix from verified inventory rather than accepting an undocumented substitution.

Würth Elektronik 150141 SMD Indicator LED Selection Guide

The Würth Elektronik 150141 family gives engineers a compact way to build single-color or two-color status indications around a common 3528-class, top-view SMD format. That apparent simplicity is useful, but it can hide important differences in wavelength, forward voltage, luminous intensity, pin behavior, and sourcing risk.

This guide uses the red 150141RS73100 as the primary choice and then shows when green, blue, yellow, or bi-color variants make more sense. It focuses on selection rather than repeating the current-limiting-resistor design process: the goal is to help engineering and procurement agree on the right visual function, footprint strategy, acceptable substitutes, and purchase controls before a board reaches production.

1. Start with the meaning of the indication

Color semantics should be defined from the product's user interaction before an MPN is placed on the BOM. A red LED is normally the clearest choice for fault, stop, protection trip, overtemperature, denied access, or a condition that requires attention, which makes 150141RS73100 a strong default for the primary alarm channel.

Red should not automatically mean "power present." On equipment with both normal and fault states, a green power or ready light paired with a red alarm light reduces ambiguity; on a one-LED product, firmware patterns may need to distinguish standby, error, and boot conditions. Write the state table first, including the LED state during reset, firmware update, loss of communications, and power collapse.

Wavelength matters because color names describe broad perception bands rather than identical results. The listed green 150141GS73100 is specified at 525 nm typical, 150141RV73100 combines 625 nm red and 570 nm bright green, and 150141YB73100 combines 590 nm yellow and 470 nm blue. For safety information, reinforce color with a label, icon, or distinct blink pattern.

2. Match brightness to the viewing environment

Luminous intensity must be selected for the installed optical path, not for a bare LED viewed on a lab bench. The primary red part is commonly evaluated at the family's 20 mA reference condition, while the available 150141 variants cover markedly different intensity levels; for example, the returned product data lists 150141GS73100 at 1000 mcd typical, 150141RV73100 at 250/60 mcd, and 150141YB73100 at 220/240 mcd at 20 mA.

A high millicandela value is not automatically better. An enclosure indicator viewed at 300 mm indoors can be uncomfortable or produce haloing if it is designed for direct outdoor visibility, while a low-intensity channel may disappear behind a smoky lens. The 120-degree viewing angle associated with the listed green and bi-color variants favors broad status visibility, but it also spreads optical power rather than concentrating it into a narrow axial spot.

Use a three-level brightness target during validation. The minimum level must remain legible at the lowest allowed current, highest ambient temperature, worst lens transmission, and least-favorable production bin; the nominal level should be comfortable in the normal environment; the maximum level should not create glare in a dark room. A prototype that passes only at 20 mA may still fail if the production firmware uses 2 mA to save energy.

Perceived brightness is color-dependent, so equal mcd values can look unequal and two dies in one bi-color package may require separate PWM duty cycles. Treat 20 mA as a comparison point rather than a mandatory operating current, and document the validated current range for production.

3. Budget forward voltage and drive headroom

Forward voltage determines whether the selected color can be driven cleanly from the available rail across tolerance and temperature. Red and yellow indicator dies are often near a 2.0 V typical reference at 20 mA, while InGaN green and blue parts are commonly near 3.2 V; the returned data explicitly lists 150141GS73100 at 3.2 V and the yellow/blue 150141YB73100 at 2.0/3.2 V typical.

That difference can decide the architecture on a 3.3 V system. A red 150141RS73100 leaves useful voltage for a series resistor and a low-side transistor, whereas a nominal 3.2 V green or blue die leaves little headroom after regulator tolerance, GPIO output drop, and cold-temperature forward-voltage increase. The result may be a green channel that dims sharply as a battery discharges even though the red channel remains stable.

For direct GPIO drive, check guaranteed output voltage plus per-pin, per-port, and total current limits. A transistor or constant-current driver is preferable when several indicators operate together, rail margin is small, or brightness matching matters. For bi-color devices, verify the schematic symbol, terminal count, internal connection, and drive direction against the current datasheet.

4. Confirm package, footprint, and optical geometry

The 3528 top-view package is a mechanical choice as much as an electrical one. A nominal 3.5 mm by 2.8 mm body offers a visible emitting area and robust pick-and-place handling, but the land pattern, courtyard, polarity mark, package height, and lens location must match the exact Würth drawing.

Do not infer footprint compatibility from the digits "3528" alone. Suppliers may use that label for different pad geometries, lens shapes, heights, thermal lands, or terminal counts, and a bi-color member can require a different pin arrangement from the two-pin 150141RS73100. Import or audit the manufacturer's symbol, footprint, and 3D model, then compare the released PCB library against the latest controlled drawing.

Top-view geometry is best when the user looks perpendicular to the PCB or a light pipe sits above it. It is a poor fit for a light pipe that enters from the board edge unless the mechanical design intentionally redirects the light; a side-view LED may give better coupling and lower enclosure loss in that case. Model the LED's emitting center relative to the enclosure aperture and include tolerance for board position, gasket compression, and light-pipe placement.

The water-clear lens used by the listed variants can yield strong output but may reveal hot spots through a transparent window. A diffused light pipe, textured lens, mixing chamber, or increased standoff can improve uniformity. Validate appearance at the minimum and maximum allowed PCB-to-panel distance because a 0.5 mm mechanical shift can change coupling more than an electrical fine-tune.

Assembly compatibility belongs in the package review. Confirm polarity, reflow limits, moisture-sensitivity classification, storage requirements, and permitted reflow cycles; J-STD-020 and J-STD-033 provide the industry framework, while the datasheet and bag label define part-specific limits.

5. Decide between mono-color and bi-color signaling

Mono-color 150141 parts minimize software, pin-count, and diagnostic complexity, while bi-color parts conserve panel area when two states must share one aperture. The 150141RS73100 is therefore the lower-risk choice for a dedicated red alarm that must remain understandable even if firmware control is simple or unavailable.

Choose the 150141GS73100 for a dedicated green or ready channel when its 525 nm color and 1000 mcd typical intensity suit the optical stack. Blue can identify connectivity, pairing, or a special function, but verify its higher forward-voltage headroom and indoor glare; the 150141BS73100 is the family candidate to investigate for that role. Yellow is useful for warning or pending conditions when red is reserved for a fault.

The 150141RV73100 combines red and bright green in one package and is attractive for fail/pass, charging/charged, or offline/online indications. Its returned data lists 625/570 nm typical wavelengths, 250/60 mcd typical intensities, and 2.0 V typical forward voltage at 20 mA, so the two colors should be validated independently rather than driven with one assumed brightness setting.

The 150141YB73100 combines yellow and blue for products that need warning plus communications or mode indication in the same aperture. Returned data lists 590/470 nm, 220/240 mcd, and 2.0/3.2 V typical at 20 mA. That split forward voltage is a reminder that each die needs its own current calculation and that a weak 3.3 V rail may limit the blue channel first.

Avoid using rapid color changes as the only diagnostic language. Define a stable default state, blink frequency, duty cycle, and transition behavior, then test users who were not involved in the design. For service equipment, print the LED code in the manual and keep it stable across product revisions.

6. Plan for temperature, lifetime, and compliance

Environmental margin should be verified against the exact suffix and operating profile before the family is approved. LED forward voltage, radiant output, color, and lifetime change with junction temperature, so a prototype at 25 degrees Celsius does not establish performance inside a sealed enclosure near a regulator or power converter.

Compare local temperature and intended current with the datasheet's maximum and derating curves, using maximum ratings as damage limits rather than design targets. For optical-safety assessment, IEC 62471 is the relevant framework. Automotive programs should require evidence of the necessary AEC-Q102 qualification instead of assuming a commercial variant qualifies.

Compliance documentation should identify the manufacturer, exact MPN, and revision. Returned records identify the family as halogen-free and RoHS- and REACH-compliant, but procurement should still collect current declarations for the production lot and destination market.

7. Build a procurement-ready specification

A procurement-ready LED line item defines acceptable evidence and substitutions instead of listing only a color and package. Use the complete manufacturer name and 150141RS73100 suffix, packaging quantity, date-code policy, compliance requirements, factory-sealed reel condition, traceability documents, and approved alternates.

Do not allow a distributor to replace "red 3528 LED" with a visually similar generic part without engineering review. Two red LEDs can differ in intensity bin, dominant wavelength, lens transparency, pad layout, polarity, package height, reflow rating, and ESD robustness. A substitution that lights during incoming inspection can still create an uneven front panel, reverse-mounted boards, or field failures.

Reel economics matter for the 73100 ordering suffix. Confirm the manufacturer's standard packing quantity and minimum order with the live supplier quote, then align prototype, pilot, and production purchases so partial reels do not undermine moisture protection or traceability. For small builds, buy sealed cut-tape or re-reel material only from a supplier that preserves the original label and can document handling.

Stock status and price change faster than electrical specifications, so treat the comparison table's price bands as budgetary planning values rather than offers. Use FindMyChip search to compare current listings across more than 200 verified distributors, then request a consolidated LED quotation for the exact MPN, quantity, target date, and ship-to country. FindMyChip's five-point authentication process and typical 24-hour response can complement franchised-channel checks when schedule or China-based pricing matters.

Recommended 150141-series products

The best family member is the one whose color, drive voltage, intensity, and optical function match the released state table. The following values summarize returned product data and practical use; consult the current Würth Elektronik datasheet and a live quote before design freeze.

Product	Color / typical wavelength	Typical intensity at 20 mA	Typical forward voltage	Budgetary planning range*	Best for
150141RS73100	Red / approximately 625 nm	Verify current datasheet and bin	Approximately 2.0 V	$0.15-$0.45	Dedicated fault, stop, alarm, or attention channel
150141GS73100	Green / 525 nm	1000 mcd	3.2 V	$0.18-$0.50	High-visibility ready, pass, or normal-status channel
150141BS73100	Blue / verify current datasheet	Verify current datasheet and bin	Typically near 3.2 V; verify	$0.18-$0.55	Connectivity, pairing, or special-mode indication
150141RV73100	Red / bright green, 625/570 nm	250/60 mcd	2.0 V	$0.25-$0.70	Two-state fail/pass or charge-status aperture
150141YB73100	Yellow / blue, 590/470 nm	220/240 mcd	2.0/3.2 V	$0.25-$0.75	Warning plus communications or mode in one aperture

*Budgetary ranges are illustrative small-to-mid-volume planning bands, not current offers. Quantity, reel format, date code, origin, and availability can move the actual quote outside these ranges.

Selection decision flowchart

The selection flow should eliminate incompatible optical and electrical choices before price comparison. Use the following sequence as a design-review checklist:

If the aperture communicates one critical fault or stop state, then start with 150141RS73100; else continue to the required state count.
If one aperture must show two mutually exclusive states, then choose a bi-color candidate: red/bright green 150141RV73100 for fail/pass or yellow/blue 150141YB73100 for warning/mode; else use separate mono-color LEDs.
If the rail is 3.3 V with direct GPIO drive, then favor red or yellow first and calculate worst-case headroom; else verify a driver or higher rail for green and blue.
If the LED sits behind a tinted lens or long light pipe, then prototype the highest-loss color and minimum-current condition; else validate direct-view glare at maximum current.
If a shared PCB footprint is required, then compare the exact terminal count, pad drawing, height, and polarity for every approved MPN; else maintain separate controlled footprints.
If the product has automotive, medical, safety, or harsh-environment requirements, then request the relevant qualification and traceability evidence; else apply the standard commercial compliance plan.
If live stock cannot cover pilot quantity plus expected production demand, then obtain a verified quote and engineering-approved alternate before release; else reserve the required lot and record the approved date code and bin.

FAQ

Is 150141RS73100 the best default red LED in the 150141 family?

150141RS73100 is the logical starting point when the product needs a dedicated red top-view indicator in the 3528 family format. It supports familiar fault and attention semantics and generally offers better voltage headroom than green or blue on a 3.3 V rail. It is not automatically best behind every lens, so confirm intensity, wavelength bin, footprint, polarity, and the complete optical stack using the current datasheet and production samples.

Can a 150141-series LED be driven directly from a microcontroller GPIO?

It can be possible at modest current, but the decision depends on the GPIO's guaranteed source or sink voltage, per-pin and total current limits, LED forward voltage, resistor tolerance, and temperature. Red usually leaves more headroom on 3.3 V than blue or InGaN green. Use a transistor or constant-current driver when multiple LEDs operate together, the rail margin is small, or brightness matching and diagnostics are production requirements.

Are mono-color and bi-color 150141 parts footprint-compatible?

Do not assume they are footprint-compatible from the shared family number or 3528 body label. A mono-color device such as 150141RS73100 is listed as a two-pin part, while a bi-color package can use a different terminal count, pin map, internal connection, and polarity convention. Compare the current mechanical drawings and create distinct schematic symbols and approved footprints whenever the manufacturer documentation shows a difference.

How should engineers compare brightness across red, green, blue, and yellow LEDs?

Compare luminous intensity at the same specified current, but validate perceived brightness in the finished enclosure because eye sensitivity varies by wavelength. Include the lens, diffuser, light pipe, viewing distance, ambient lighting, temperature, and production bins. For a bi-color device, tune each die separately with resistor values or PWM so the user sees balanced states rather than assuming equal current or equal millicandela values will look equal.

What should procurement require when buying 150141RS73100?

Require the full Würth Elektronik MPN, authorized or verified source identity, original label and reel traceability, date-code policy, packaging condition, compliance declarations, and a live quantity-specific quote. Reject undocumented substitutions described only as "red 3528 LED." For constrained supply, engineering should approve alternates using mechanical, electrical, optical, assembly, and reliability evidence before purchasing rather than after an incoming lot arrives.

Final recommendation

The safest selection strategy is to anchor the design on function, validate the complete optical path, and make procurement controls part of the engineering specification. Use 150141RS73100 as the primary red alarm or attention LED when a dedicated 3528 top-view channel is appropriate, then move to green, blue, yellow, or bi-color members only when the state model and drive architecture justify them.

Before release, verify the latest datasheet revision, exact footprint, polarity, intensity bin, forward-voltage limits, reflow conditions, compliance evidence, and reel quantity. Then compare current 150141 inventory or submit the exact BOM quantity through FindMyChip RFQ so price, date code, packaging, and delivery can be evaluated together rather than as separate late-stage surprises.