This article is for brands and traders buying USB-C cables. The core point is simple: fitting is not the same as working. The price difference often hides in the pins and the chip. For the USB Type-C connector range we supply, the pin definition is stated on the datasheet.
1. A full-featured Type-C connector is 24-pin
USB Type-C is defined in the USB-IF specification as a 24-pin, full-featured connector, carrying USB 2.0 data, the high-speed differential pairs (SuperSpeed/USB4), the configuration channel (CC), sideband (SBU), power (VBUS) and ground (GND). CC handles capability negotiation between the device and the cable, and SBU is used by some Alt Modes and audio accessories. Without those pins a cable cannot properly identify itself to the device, so the device falls back to the most conservative power it can offer. A genuinely full-featured cable supplies power, data and video at once because each of those pins does its job.
2. Why 16-pin cables exist
To cut cost, some plugs use a reduced pin count (16 pins is common), usually removing the data-related pins. The result is a cable that only charges or supplies power: it cannot carry data, and it cannot drive a dock or video. Which pins are omitted varies by manufacturer, so the supplier's pinout drawing is what governs — not the words "Type-C" on the listing.
3. How to tell whether a cable carries data
- Check the datasheet wording: does it state full-featured, USB 2.0 data, SuperSpeed, USB4 or Alt Mode?
- Check for an e-marker: above 3A or at high power, USB PD requires an e-marker chip to identify the cable's capability (source: USB-IF)
- Check USB-IF testing and the TID: verifiable third-party evidence of compliance
- Check the label: a cable marked "charge only" cannot carry data by definition
4. Decide the use before you trim pins
- Charging only, no data: a reduced-pin charging cable is cheaper and a reasonable choice
- Dock, monitor, SSD or data sync: a full-featured cable is required, with the SuperSpeed/USB4 and Alt Mode your use needs confirmed
- High-power fast charging: look at the e-marker and the gauge, not only the wattage printed on the jacket
Put the use into the RFQ so the supplier can specify the right construction, rather than buying cheap first and returning a batch later.
5. Why data and video need a full-featured cable
USB 2.0 data, SuperSpeed/USB4 data and DisplayPort and other Alt Mode video all depend on the corresponding data pins. Once a reduced-pin charging cable has left them out, transport is physically impossible — even with the device, cable and port all in place, the system will not detect a monitor or a dock. A large share of returns for docks, monitors and portable SSDs comes down to the buyer having received a charging cable.
6. How to verify a cable
Before a bulk order, do three things: test with a device that is known to need data (a dock, a monitor, an SSD); check the pinout drawing and datasheet the supplier provides; and keep samples and test reports as the evidence base for any later dispute. Judging a cable by "it charges when I plug it in" is the same as not testing it.
7. What to write into the RFQ
- Use: charging only, data, or video — state it explicitly
- Pins: request the plug pinout drawing and the matching wire gauge
- E-marker: state whether it is needed and the maximum power supported
- Testing: insertion loss, eye diagram or USB-IF test reports
- Documents: datasheet, test reports and packaging labels
8. Common traps
- Treating "it charges" as "full-featured", which shows up as laptop-dock and monitor returns
- Using a "Type-C" cable with no stated pin definition as a data cable, and discovering after the batch that it only charges
- Reading only the "240W" claim and ignoring the e-marker and the gauge
For the speed and power side of the same connector — speed grades, the e-marker and 240W EPR — see USB4 vs USB 3.2: a buyer's guide to 240W USB-C cables. If you sell into the EU, our EU common charger directive article sets out what the mandatory USB-C port changes for buyers.
Sources
- USB-IF, USB Power Delivery (e-marker, 240W, Type-C specification): https://www.usb.org/usb-charger-pd
- USB-IF, specifications and documents (USB Type-C specification and compliance test documents): https://www.usb.org/documents
- Note: 24-pin is the USB-IF full-featured definition; reduced pin counts such as 16-pin are an industry cost-reduction approach, and the exact pins omitted vary by manufacturer with no single public standard — the supplier's pinout drawing governs.