Panel Indicator LED Selection

Question

Problem: Panel Indicator LED Selection. Solve this hands-on electronics task on EWskills.

Accepted Answer

1. Component Purpose

A Power ON indicator LED gives the operator instant visual confirmation that the board is powered and running. Green is the universal color for “power OK” or “normal operation” in electronics.

A 1206 SMD package is large enough to be clearly visible on a front panel and easy to solder during PCB assembly.

Required: Green · 1206 · SMD · Vf 2.0–3.4V · 20mA · ≥20mcd · ≥100° viewing · −40°C to +85°C · RoHS

2. How to Find It on DigiKey

Go to DigiKey.com → Optoelectronics → LED Indication - Discrete

Apply these filters:

Color → Green
Package / Case → 1206 (3216 Metric)
Mounting Type → Surface Mount
Millicandela Rating → 20mcd or higher
Viewing Angle → 100° or wider
Part Status → Active

Tip: When calculating the series resistor: R = (Vsupply − Vf) / If. For 5V supply and Vf = 2.0V at 20mA: R = (5 − 2) / 0.020 = 150Ω. Use a standard 150Ω resistor.

3. Key Specifications & What They Mean

Specification	Required	Why
Color	Green	Standard for power/status OK indication.
Package	1206	Visible size for front panel use.
Forward Voltage	2.0V to 3.4V	Needed to calculate series resistor.
Test Current	20mA	Standard full-brightness drive current.
Luminous Intensity	≥20mcd	Clearly visible under indoor lighting.
Viewing Angle	≥100°	Visible from wide range of positions.
Temp Range	−40°C to +85°C	Standard indoor industrial range.
RoHS	Yes	Compliance required.

4. Selecting a Safe, Production-Ready Part

The filtered list will show matching parts. Before you pick one, check: Is it Active? Is stock available? Is the manufacturer reputable? Is a datasheet available?

Full checklist: How to Select a Safe, Production-Ready Component — EWskills Guide

5. Filtered DigiKey Link

➡ View Matching Parts — Green, 1206, ≥20mcd, ≥100°, SMD

38. Panel Indicator LED Selection