USB-C - Power Delivery & Data Cables

Device to check USB-C cables

Identify capabilities of a USB-C cables using tester ^{1 2}

USB Type-C connector…

• …adapters for widely used (legacy) Type-A and Micro USB
• …support multiple functionalities …higher data transfer speeds
• 24 pin connector …oval-shaped interface …rotationally-symmetrical
  • Connectors & cables do not need to support all pins
  • D (data) pins come in pairs
  • 4x GND and VBUS pins
  • 4x TX/RX pairs for increased data transmission speeds
  • CC1/CC2 …detect connector orientation …power modes
  • SBU for audio and video

Modes…

• MHL (Mobile High-Definition) to connect smart phones to a TV
• HDMI to connect with a standard HDMI display
• DisplayPort compatible with HDMI/DVI/VGA
• Thunderbolt 3
  • Connect with a 4k monitor (support DisplayPort)
  • Max. 40Gbps data transfer
  • 0.5m, active cable if longer
• USB BC (Battery Charging)
• USB PD (Power Delivery) over USB Type-C cables
• USB-IF (USB Implementers Forum) cable certification program
  • Environmental, electrical and mechanical standards

Power

Four VBUS connections carry power…

• …used to operate and charge devices
• …two additional GND pins for ground
• Terminology…
  • DFP …Downstream Facing Port (power provider)
  • UFP …Upstream Facing Port (power receiver)
  • DRP …Dual Role Power (supports both modes)
  • PPS …Programmable Power Supply (dynamic voltage)
• Starts in legacy mode
  • …requires 5.1 Ohm pull-down resistors on CC pins
  • …otherwise no power will be provided
  • …max 5V/3A without power negotiation
• USB BC (Battery Charging)…
• USB PD (Power delivery) …fast charging
  • …“handshake” …power delivery negotiation process
  • …voltages: 5V, 9V, 15V, 20V, 28V, 36V, and 48V

Spec.	Max. Voltage (V)	Max. Current (A)	Max. Power (W)
USB 2.0	5	0.5	2.5
USB BC 1.2	5	1.5	7.5
USB C 3.0	5	3	15
USB BC 2	5	5	25
USB C PD 2.0/3.0	20	5	100

The cables matters

• …power can only flow at a rate the cable can handle
  • …operates with strict safety standards
  • …prevent cables from overheating
• E-Marker …chip embedded into the plug ³
  • …required in USB-3.1 and newer cables
  • …indicates power carrying capabilities
  • …enables power delivery with 20V/3A, 60W (and more)
• ERP (Extended Power Range)
• Respected brands
  • Anker
  • Cable Matters
  • Dockcase

Data Transfer

Use a cable that supports faster data transfer…

• …usually marked with a DisplayPort or Thunderbolt symbol
• 10Gb/s requires at least RX1/TX1
• 20Gb/s …Gen 2x2 (both high speed connections)

Data transfer speeds over USB:

Spec.	Speed (Gbps)
USB 2.0	0.48
USB 3.0	5
USB 3.1 Gen 1	5
USB 3.1 Gen 2	10
USB 3.2	20
USB 4.0	40

Footnotes

1. Treedix USB Cable Tester Board
   http://treedix.com

2. USB Cable Tester, Alvaro Prieto, GitHub, CC BY 4.0
   https://github.com/alvarop/usb_c_cable_tester
   https://github.com/coryalder/usb-c-tester-case

3. Designing a Type-C electronically marked cable – Part 1
   https://www.eeworldonline.com/designing-a-type-c-electronically-marked-cable-part-1/