β 13 min readThe Next Generation of High-Performance FPGAs: Tang Mega 138K
Confused by the sheer number of FPGA boards on the market? If you are looking for serious horsepowerβPCIe acceleration, high-speed transceivers, and e
Read Article β| Bulk Pricing | ||
|---|---|---|
| QTY | Unit Price(Inlc. GST) | |
| 25+ | βΉ24.50 βΉ 20.76 + 3.74 GST | |
| 50+ | βΉ24.25 βΉ 20.55 + 3.7 GST | |
| 75+ | βΉ24.00 βΉ 20.34 + 3.66 GST | |
| 100+ | βΉ23.50 βΉ 19.92 + 3.59 GST | |
Ultra-compact PJ-320D 3.5mm audio connector. Features 4 surface-mount (SMD) pins for flat, low-profile PCB soldering. Ideal for Bluetooth speakers, audio receivers, and custom sound boards.
Streamline your audio connections. When designing portable electronics like Bluetooth speakers or pocket-sized synthesizers, internal space is a premium. The PJ-320D 3.5mm Audio Jack utilizes a Surface Mount Technology (SMD) footprint, meaning it solders completely flush to the top layer of your circuit board without requiring space-consuming through-holes on the bottom.
4-Pin Versatility and Insertion Detection This jack features four distinct flat metal tabs. In a typical PJ-320D configuration, these pins correspond to Left Audio, Right Audio, Ground, and an internal Detection Switch. The detection switch is incredibly useful for modern electronics: it allows your microcontroller or amplifier to physically "know" when a user has plugged in headphones, automatically muting the main external speakers so the audio only plays through the headset.
Robust, Heat-Resistant Design Designed for automated factory assembly, the jack is housed in a high-temperature black plastic casing capable of surviving the intense heat of an SMT reflow oven. The internal contacts are engineered with strong spring tension, providing a satisfying "click" when a 3.5mm cable is inserted and ensuring a clean, static-free audio signal even when the device is moved or bumped.
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)
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).
What are the 4 pins for? Left Audio, Right Audio, Ground, and a Switch pin (used to detect when a headphone is plugged in).
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.
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.
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.
Is it stereo? Yes, it supports stereo (Left/Right) audio.
Is it waterproof? No.
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.
What are the dimensions? Approx 14mm x 6mm x 5mm (L x W x H).
Why is it called a "Patch" connector? "Patch" is often a translation error for "SMD Pad" or "Surface Patch" mounting.
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.
Can I use hot air? Yes, hot air is the best way to remove the old one.
Is this PJ-320A or PJ-320D? This is the D version (SMD). The A version is typically Through-Hole.
What voltage can it handle? Audio signals are low voltage (approx 1-2V). The jack is rated for up to 30V DC.
Does it include the AUX cable? No, this is just the bare connector component.
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.
Is the plastic heat resistant? Yes, it is designed to withstand reflow soldering temperatures for a short time.
Can I use it on a breadboard? No, SMD parts do not fit into breadboards. You would need a breakout adapter.
Are the contacts gold plated? Usually, they are nickel-plated or gold-flash for corrosion resistance.
Is there a datasheet? Search for "PJ-320D Datasheet" to see the exact mechanical drawing.


Probots sells every Electronics Part for your next Project. You can order 10,000+ Electronic Parts Online - Arduino, Raspberry Pi, NodeMCU Development Boards, Sensors, Motors, Motor Drivers, SMPS, Plastic Enclosures etc in India directly on probots.co.in
We delivery electronics components and parts throughout India using standard couriers like Bluedart, Delhivery & India Post.
For order related queries contact -
Probots sells every Electronics Part for your next Project. You can order 10,000+ Electronic Parts Online - Arduino, Raspberry Pi, NodeMCU Development Boards, Sensors, Motors, Motor Drivers, SMPS, Plastic Enclosures etc in India directly on probots.co.in
We offer specialized services for Bulk, Wholesale & B2B Customers like discounted prices, additional shipping options, customised products, etc . Customer with large quantity & regular orders qualify for the specialised discounted rates.
We also offer dedicated sales team to assist you with the order process by providing sales quotations, PI, technical support for choosing products, etc.
Note: Business Orders are processed manually and usually take 1-3 days to process compared to placing the order directly on our website. Please plan your purchases accordingly.
Need Help?
For bulk enquiries contact us by -
Probots Electronics is highly regarded for its highly skilled team, offering expert guidance and knowledgeable support to ensure customers find the right components for their specific technical projects. Despite some concerns regarding delivery consistency, most clients report prompt and commendable service, highlighting the store's reliability and professional attitude toward customer care.
β 13 min readConfused by the sheer number of FPGA boards on the market? If you are looking for serious horsepowerβPCIe acceleration, high-speed transceivers, and e
Read Article β
β 20 min readVol. 31 | Fluid Dynamics for Silicon Brains You want to build an automated cocktail maker or a self-watering greenhouse, but your code is flawless and
Read Article β
β 9 min readWorkbench Vol. 24 π The Project Trifecta: 3 Builds to Start Today We don’t just stock parts; we curate ecosystems. This weekβs arrivals are desi
Read Article β