5. Select a Resistor to Drive an LED

Step1: Design Calculation Resistor

• Voltage across resistor = 12V − 2V = 10V
• Required resistance = 10V ÷ 0.022A ≈ 454.5Ω → Use standard value 470Ω
• Power dissipation = I² × R ≈ (0.022)² × 470 ≈ 0.227W

To maintain a safe thermal margin (around 50%), the minimum recommended resistor power rating is:

≥0.33W (preferably 0.5W)

Step 2: Go to DigiKey

Visit https://www.digikey.com

Step 3: Navigate to Resistors

Products → Resistors → Chip Resistors - Surface Mount

Step 4: Apply Filters

• Resistance: 470 Ω
• Tolerance: ±5%
• Power Rating: ≥0.33W (e.g., 0.5W)
• Mounting Type: Surface Mount

Step 5: Choose a Part That:

• Is in stock
• Has Active status
• Comes from trusted brands (Yageo, Vishay, KOA, etc.)
• Has a datasheet available
• Offering better pricing
   

Step 6: Submit Part Number

Click on the part number → double-check all specs → copy the DigiKey part number and submit it.
Click here to check the filtered page from DigiKey