PJ-320D 3.5mm Female Audio Jack - 4-Pin SMD / SMT Surface Mount Socket

Specifications

• Model: PJ-320D (SMD Type).

• Connector Size: 3.5mm.

• Pins: 4 Surface Mount Pads.

• Housing: High-Temp Plastic (Black).

• Rating: 30V DC / 0.5A.

• Insertion Force: 3-20N.

Compatibility & Platform Support

• Bluetooth Speakers: Common replacement for JBL, Boat, and generic speaker AUX ports.

• Development Boards: Used on custom PCBs requiring a compact audio jack.

Virtual Technician: Wiring & Safety ⚠️

• Soldering: This is an SMD component. You will need a fine-tip soldering iron or a hot air rework station to install it properly.

• Removal: Removing the old, broken jack can be tricky. Use desoldering wick or a hot air gun to melt all 4 pads simultaneously so you don't rip the traces off the PCB.

• Pinout Check: Although "PJ-320D" is a standard model, manufacturers sometimes change pin layouts. Always visually compare the pad positions of your old broken jack with the new one before soldering.

Accessories

• Included in the Package:

  • 1 x PJ-320D 3.5mm SMD Audio Socket

Frequently Asked Questions (FAQ)

1. Is this for through-hole PCBs? No, this is an SMD (Surface Mount) part. The legs sit flat on the board surface. If your board has holes for the legs, you need the "DIP" version (PJ-307 or similar).

2. What are the 4 pins for? Left Audio, Right Audio, Ground, and a Switch pin (used to detect when a headphone is plugged in).

3. Will this fit my JBL/Boat speaker? It is a very common standard, but you must compare the photo and the soldering footprint with your broken part to be 100% sure.

4. How does the switch work? When the jack is empty, the Switch pin is connected to one of the audio pins (usually Left or Ground). When you plug a cable in, the metal spring bends and breaks this connection.

5. Can I solder this with a regular iron? Yes, but you need a fine tip and steady hand. Tacking one pin first helps align it.

6. Is it stereo? Yes, it supports stereo (Left/Right) audio.

7. Is it waterproof? No.

8. Can I use it for a microphone? Standard PJ-320D is usually for 3-pole (Stereo) plugs. It might not support the 4th Microphone ring found on headsets properly.

9. What are the dimensions? Approx 14mm x 6mm x 5mm (L x W x H).

10. Why is it called a "Patch" connector? "Patch" is often a translation error for "SMD Pad" or "Surface Patch" mounting.

11. Do I need glue? The solder holds it in place, but standard SMD jacks rely on the solder pads for mechanical strength. Be gentle when plugging/unplugging.

12. Can I use hot air? Yes, hot air is the best way to remove the old one.

13. Is this PJ-320A or PJ-320D? This is the D version (SMD). The A version is typically Through-Hole.

14. What voltage can it handle? Audio signals are low voltage (approx 1-2V). The jack is rated for up to 30V DC.

15. Does it include the AUX cable? No, this is just the bare connector component.

16. Why is my speaker not switching to Aux mode? The "Detection Switch" pin inside your old jack might be broken or dirty. Replacing the jack usually fixes this.

17. Is the plastic heat resistant? Yes, it is designed to withstand reflow soldering temperatures for a short time.

18. Can I use it on a breadboard? No, SMD parts do not fit into breadboards. You would need a breakout adapter.

19. Are the contacts gold plated? Usually, they are nickel-plated or gold-flash for corrosion resistance.

20. Is there a datasheet? Search for "PJ-320D Datasheet" to see the exact mechanical drawing.