38. Panel Indicator LED Selection
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