3-Pin Magnetic Connector | Promax Pogo Pin

How to Choose the Right 3-Pin Magnetic Connector

A 3-pin magnetic connector adds a third contact to the standard power pair, opening up signal, sense, or low-speed data lines. It’s the entry point for combined power-and-data applications without the cost of a USB or multi-pin interface. Use the steps below to lock in your spec.

1. Define the role of the third pin. Decide whether the third pin carries a signal, identifies the cable, drives a sense line, or runs a low-speed data path. The decision affects contact spacing, shielding, and plating. Tell our engineers what the third line does and we’ll match the pin geometry.
2. Match the current rating to your peak load. Our standard 3-pin parts handle up to 3A per contact at 12V. With three contacts in parallel, the total current capacity reaches 9A — enough for most fast-charge and accessory-power applications. Higher-current variants are available on request.
3. Verify contact resistance for both power and signal paths. Standard 3-pin connectors hold contact resistance at 50 mΩ or below. That’s low enough to keep voltage drop negligible at 3A and signal integrity stable on the third line. Tighter resistance is available when low-noise sensing matters.
4. Confirm the operating temperature and humidity range. Standard 3-pin parts run from –40°C to +85°C, with humidity tolerance from 10%RH to 90%RH. The wider low-temperature rating suits outdoor wearables, automotive accessories, and industrial sensor applications.
5. Check the mechanical life rating against your charge cycle. Standard 3-pin connectors are rated for 10,000 mating cycles. That covers nine years of daily charging or roughly three years for products mated multiple times per day. Higher cycle counts are achievable during custom design.
6. Pick the magnet grade and housing geometry. The N52 magnet in our standard 3-pin parts holds firmly in compact housings. We adjust magnet size, polarity, and contact pitch to fit slim wearables, charging docks, or rugged enclosures. Symmetrical magnet layouts allow mate-either-way designs.
7. Confirm plating, materials, and certifications. Standard contacts use Gold plating over a copper alloy base. Promax holds ISO 9001, ISO 14001, ISO 45001, and IECQ QC080000, and all 3-pin connectors are RoHS-compliant. Thicker plating or alternative finishes are available during custom design.

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