USB Type-C DP Alt Mode
Full-featured USB Type-C and DP Alt Mode
USB Type C DP Alt Mode In English collateral the shorthand DP Alt Mode (DisplayPort Alternate Mode) is often used for the same idea Chinese vendors call "一线通": one full featured USB Type C cable that carries video, high speed data and charging together, even though that bundle is not a single formal standard name Core capabilities (three in one) Video (Display) Via DisplayPort Alternate Mode (DP Alt Mode) or Thunderbolt on USB C, phones and laptops can drive a monitor, TV or projector Typical resolutions include 1080p and 4K@60Hz depending on the device and cable Power (Power Delivery, PD) USB Power Delivery enables bidirectional power up to 100W (20V/5A) or even 240W Example: a monitor powers a laptop over Type C while receiving its video signal Data (USB) USB 3.2, USB4 and similar protocols can reach 10Gbps, 20Gbps or 40–80Gbps depending on hardware USB Type C signaling with DP Alt Mode To understand Type C, start from the pin map As shown, the receptacle has four TX/RX differential pairs, two legacy USB D+/D pairs, one SBU pair, two CC pins, plus four VBUS pins and grounds Normally USB 3.x uses two TX/RX pairs for SuperSpeed data: orientation one routes TX1/RX1, orientation two routes TX2/RX2 So two differential pairs are always idle for a given plug orientation DP Alt Mode carries DisplayPort over those two "redundant" differential pairs so USB 3.x and DP can run together USB 2.0 stays on D+/D , which is why USB 2.0 (and even USB 1.x) devices keep reversible plug convenience after moving to Type C Combined with a DP only style lane map, you can also run DP plus USB 2.0 using four TX/RX lanes for DP while data stays on D+/D Two CC pins and two SBU wires also exist CC mainly serves Power Delivery negotiation and plug orientation detection: CC1 when inserted one way, CC2 when flipped When DP is active, SBU becomes the AUX P/AUX N pair (polarity swaps with orientation) for DPCD, EDID and related sideband traffic Typical device support Apple MacBook (2016 and later): Thunderbolt 3/4 ports generally offer the best full featured Type C experience Windows ultrabooks: many models from the last few years ship at least one full featured Type C port with DP or Thunderbolt markings; budget or older units may omit it Android phones: needs hardware DP output plus a vendor desktop mode (Samsung DeX, Huawei desktop mode, Xiaomi and others); not every Type C phone qualifies iPad Pro/Air: supports external display extension (Sidecar or mirroring) Nintendo Switch: Type C supports DP output but pairing with portable monitors can be picky about PD; verify Switch compatibility to avoid missing TV mode or unstable power How to verify DP Alt Mode support Marketing language Phrases like "single cable Type C video", "full featured Type C", "USB C with video" or "supports DP Alt Mode" are strong indicators Charging phrases such as "reverse charging", "charges your laptop/phone" or "USB PD" may apply because PD reverse charging is common on full featured docks Icons All three icon styles above imply DP Alt Mode support The first two imply DP Alt Mode; the third does not References https://za3c.com.tw/mhl %E5%92%8C usb typec dp alt mode %E6%94%AF%E6%8F%B4%E6%B8%85%E5%96%AE/ https://www.adreamertech.cn/news/NewsDetail/94
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