2pcs Barrel Jack 2.1mm x 5.5mm

🔹 2PCS DC Power Barrel Jack – 2.1mm x 5.5mm (PCB Mount)

Standard 2.1mm inner diameter / 5.5mm outer diameter DC power jack connectors, designed for direct mounting onto printed circuit boards (PCBs). They provide a secure and low-profile connection for powering custom PCBs, development boards, and electronic devices using common wall adapter plugs.

✅ Specifications:

• Connector Type: DC Power Barrel Jack (Receptacle)

• Mounting Style: PCB Mount (Through-Hole, THT)

• Inner Pin Diameter (Tip): 2.1mm

• Outer Sleeve Diameter (Sleeve): 5.5mm

• Center Polarity: Typically Center Positive (+) (Most Common)
  Always verify specific product listing/datasheet.

• Terminal Pins: 3 through-hole pins (or sometimes 2)

• Standard Pinout (3-pin, bottom view):

  1. Center Pin / Tip Contact (Positive, if center positive)

  2. Outer Sleeve Contact (Negative/Ground)

  3. Normally Closed (NC) Switch Contact (Breaks connection when plug is inserted)

• PCB Hole Spacing: Standard pin spacing (e.g., 3.5mm between pins, check datasheet)

• Rated Voltage/Current: ~12V DC, 1A-2A (typical for standard PCB jacks)

• Material: Nickel-plated brass contacts, plastic housing

• Height: Low profile above PCB (varies by model)

• Quantity: 2 pieces

⚙️ Features:

• PCB Integrated Design: Saves space and provides a clean, soldered connection directly to your circuit board.

• Universal Compatibility: Matches the world’s most common DC power plug size.

• Optional Switching Function: The third pin allows for automatic power source switching (e.g., between battery and external adapter).

• Secure Mechanical Mount: Plastic housing and multiple pins provide stability when a plug is inserted/removed.

• Cost-Effective & Standard: The go-to solution for adding DC power input to any custom PCB.

📦 Typical Applications:

• Custom PCB Projects: The standard power input for DIY Arduino shields, Raspberry Pi HATs, audio amplifier boards, and LED controllers.

• Development & Prototype Boards: Found on countless evaluation and breakout boards.

• Consumer Electronics Repair: Direct replacement for damaged jacks in gadgets, routers, and small appliances.

• Battery-Powered Devices: Enables automatic switchover from battery to wall power when plugged in (using the NC pin).

• 3D Printer & CNC Controller Boards: Standard input for many open-source controller boards.

🔧 PCB Layout & Wiring Guide:

1. Footprint is Critical: Use the exact manufacturer-recommended footprint (pad size, hole diameter, and pin spacing) in your PCB design. A common mistake is using the wrong footprint.

2. Standard 3-Pin Connection (Center Positive):

   • Pin 1 (Center/Tip): Connect to your board’s VCC/V+ rail.

   • Pin 2 (Sleeve): Connect to your board’s GND plane.

   • Pin 3 (NC Switch): Connect to the positive side of a battery or alternate power source. When a plug is inserted, this connection opens.

3. If No Battery: You can leave Pin 3 (NC) unconnected or tie it to Pin 1.

4. Polarity Protection: It is highly recommended to add a series diode or P-channel MOSFET for reverse polarity protection on the input, as users may still use a center-negative adapter by mistake.

5. Mechanical Stress: Ensure the PCB is supported near the jack if the board will experience frequent plug insertion/removal. Consider adding a strain relief bracket.

⚠️ Critical Safety & Design Notes:

• CONFIRM POLARITY: Before soldering, verify the jack’s polarity with a multimeter in continuity mode. Match it to your power supply’s plug polarity.

• Current Limit: Standard PCB jacks are often rated for 1A or 2A continuous. For higher currents, source a “power jack” rated for 5A+.

• Input Protection: Always include at least a fuse or polyfuse and a protection diode on the power input line to safeguard your circuit.

• Fit the Plug: Ensure the jack’s depth accepts the full length of the plug’s barrel for a reliable connection.