1. Key points

  • USB PD 3.1 raises the maximum from 100W (20V/5A) to 240W.
  • New fixed voltages of 28V, 36V and 48V provide 140W, 180W and 240W.
  • Devices draw only what they negotiate; a higher-rated charger does not force extra power.
  • Cables must be rated for the current: 5A cables above 60W, EPR cables for above 100W.

2. Negotiation

Charger and device agree on a power level before delivering higher voltages.

3. Extended Power Range

USB PD 3.1 added EPR levels for laptops and larger devices.

4. USB4

USB4 supports up to 80 Gbps over certified cables and commonly pairs with PD charging.