TYPE-C-31-M-12 PCB design guide and datasheet

The TYPE-C-31-M-12 is the generic 16-pin USB-C receptacle, the connector on a large share of hobby and low-volume boards that charge or enumerate over USB-C. It is a right-angle surface-mount part (8.94 × 7.35 × 3.16 mm) with 16 SMT signal leads plus four through-board shell retention legs, carrying only the USB 2.0 subset of the Type-C pinout: VBUS, GND, D+/D−, CC1/CC2, and SBU. The base part is rated 5 A at 20 V, with 10,000 mating cycles.

A note on names: LCSC catalogs this part under "Korean Hroparts Elec", but that is the distributor's naming: the manufacturer brands itself HRO (krhro.com), and its drawing PDF covers the whole M-12 family, including the M-12A variant in high-conductivity copper rated 6 A. The part is also endlessly cloned, so "TYPE-C-31-M-12" on a marketplace listing describes a class of connector more than a guaranteed footprint.

USB-C failures on boards using this connector are rarely the connector's fault. They are design mistakes around it: missing or shared CC pull-downs, mishandled duplicate USB 2.0 pads, a footprint copied from the wrong clone, or unsoldered retention legs. Each is covered below.

What breaks boards

1. 01

   CC1 and CC2 each need their own 5.1 kΩ pull-down

   For a board that takes power, the USB Type-C specification requires a separate Rd pull-down of 5.1 kΩ from CC1 to GND and another from CC2 to GND. A single resistor shared between both CC pins (the mistake that shipped on the Raspberry Pi 4) breaks orientation and cable detection with e-marked C-to-C cables, and is the number-one reason a board charges from an A-to-C cable but not from C-to-C. Note this is a board design rule from the USB-C spec, not a parameter on the connector drawing.

2. 02

   The 16-pin variant is USB 2.0 only; tie the duplicated data pads pairwise

   This connector has no SuperSpeed pairs; the pin table is GND on A1/B12/A12/B1, VBUS on A4/B9/A9/B4, CC1 on A5, CC2 on B5, and two copies of the USB 2.0 data pair (A6/A7 and B6/B7) so either plug orientation lands on live pads. Tie DP1 to DP2 and DN1 to DN2 with short stubs. If your product needs USB 3.x, this whole connector class is out: you need a 24-pin receptacle.

3. 03

   Verify the footprint against the exact vendor drawing, not the part name

   Because the part is generic and widely cloned, pad geometry, mid-mount versus top-mount bodies, and retention-leg holes vary between vendors selling under the same name. The HRO drawing specifies eight 0.30 mm signal pads on 0.5 mm pitch plus four wider 0.60 mm shared VBUS/GND pads, with through-board holes for the four shell legs. Pull the drawing for the connector you will actually buy, check it against your footprint, and keep copper clear of the retention-leg holes.

4. 04

   Solder the shell retention legs: they carry the mechanical load

   Insertion force is specified at 5–20 N and removal at 8–20 N, and that load must not be carried by the sixteen 0.3 mm signal joints. The four through-board legs are the mechanical anchor: give them plated holes and solder them. Placement matters too: the drawing references the recommended layout to the PCB edge, so board-edge position tolerance directly affects how fully a cable seats.

5. 05

   Merge the VBUS pads with real copper, and protect the port

   VBUS appears on four pins (A4/B9/A9/B4) and GND on four more; merge each group with copper sized for your actual current budget. The connector itself is rated 5 A (6 A for the M-12A variant): the often-quoted 3 A figure is the USB-C default-current design target for board copper, not this connector's limit. Add ESD protection such as a USBLC6-2SC6 on D+/D−, and consider a PPTC polyfuse on VBUS so a shorted cable doesn't take out the board.

Key specifications

Verified against the manufacturer datasheet on 2026-07-09. Confirm the current revision before production use.

Alternatives

• USB4105-GF-A: GCT's connector in the same 16-pin USB 2.0 class, with a properly documented, stable footprint from a brand-name vendor: the upgrade path when clone footprint roulette isn't acceptable.
• 24-pin USB-C receptacles (JST, Amphenol): full-featured Type-C with SuperSpeed pairs for USB 3.x designs; finer-pitch and harder to solder, often hybrid SMT/through-hole.
• 6-pin power-only USB-C: just VBUS, GND, and CC pins for 5 V charge-only designs (up to 3 A default USB-C current); no data pads at all, and easier to hand-solder.

Common questions

Why does my USB-C board charge from an A-to-C cable but not C-to-C?

Almost always the CC resistors. A power-sinking board needs an individual 5.1 kΩ pull-down on CC1 and another on CC2 per the USB-C specification; a shared single resistor breaks detection with e-marked C-to-C cables, so the source never turns on VBUS. A-to-C cables mask the error because the resistor lives in the cable.

Can the 16-pin USB-C connector do USB 3.0?

No. The 16-pin variant carries only the USB 2.0 subset (VBUS, GND, CC, SBU, and duplicated D+/D− pads for both plug orientations), with no SuperSpeed pairs. USB 3.x requires a full-featured 24-pin receptacle.

How much current can the TYPE-C-31-M-12 carry?

The manufacturer drawing rates the base connector at 5 A and 20 V, and the M-12A high-conductivity-copper variant at 6 A. The commonly quoted 3 A is the USB-C default-current design target for your board copper, not the connector's limit: size the merged VBUS pours for whatever current you actually negotiate.

Where is the TYPE-C-31-M-12 datasheet?

The manufacturer is HRO (krhro.com; LCSC lists it as "Korean Hroparts Elec"), and the official drawing PDF covering the M-12, M-12A, M-12B, and M-12C variants is attached to the HRO product page linked above. Because clones abound, verify the drawing matches the exact vendor you buy from.

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