USB Power and Charging Technology

USB 2.0 (BC 1.2)

  • PD: Portable Device
  • SDP: Standard Downstream Port - Data + 500mA for USB 2.0
  • CDP: Charging Downstream Port - Data + 1500mA
  • DCP: Dedicated Charging Port - 1500mA

Primary Detection

  1. VBUS > 0.8V
  2. 0.5-0.7V on DP
  3. Check DM Voltage
  4. If DM is lower than DP, SDP (500mA).
    a. SDP has 15K Ohm pull down on DP and DM.
  5. If DM is roughly equal to DP, CDP/DCP (1500mA).
    a. CDP/DCP has 200 Ohm resistor between DP and DM.

USB 3.0 Type C

  • Supports USB BC 1.2 via DM and DP
  • 500mA (USB 2.0), 900mA (USB 3.0), 1500mA, 3000mA
  • DFP: Rp pull up
  • UFP: Rd pull down
  • e-marked/Active: Ra pull down

USB Type C DFP CC1/CC2 Rp Pull Up

  1. 500mA USB 2.0 or 900mA USB 3.0: 56K to 5V or 36K to 3.3V
  2. 1500mA: 22K to 5V or 12K to 3.3V
  3. 3000mA: 10K to 5V or 4.7K to 3.3V

USB Type C UFP CC1/CC2 Rp Pull Down

  1. 1500mA or 3000mA: 5.1K to GND

USB Type C Active Ra Pull Down

  1. VCONN to GND 0.8-1.2K

USB Power Delivery 2.0

  • 1-wire over CC 300K Baud
  • DFP Bus Master
  • 32-bit 4b/5b BMC Encoding with CRC32 + Retry
  • Above 5V operation
  • Above 3A operation
  • Passive cable up for to 60W
  • e-marked cable use 70mW max for above > 60W
  • Active cable use 1W max

Alternative Modes

  • TX1
  • RX1
  • TX2
  • RX2
  • SBU1
  • SBU2

Cable Requirements

  • 50 Ohm impedance CC/SBU1/SBU2
  • 250mV GND Vdrop
  • 500mV VBUS Vdrop
  • USB 2.0: 4M Max
  • USB 5Gb: 2M
  • USB 10Gb: 1M

Resources