Guide · 7 min read
USB-C Power Delivery, explained.
PD is a conversation, not a firehose: the charger lists what it can supply, the device picks a contract, and both sides hold to it. Understand that one idea and every confusing spec on a charger listing resolves itself.
The negotiation, step by step
Within milliseconds of plugging in: (1) the adapter advertises its profiles — e.g. 5V/3A, 9V/3A, 15V/3A, 20V/3.25A for a 65W unit; (2) the device requests the profile it wants; (3) the adapter switches its output to match; (4) both continuously monitor and can renegotiate (which is the blip you see on multi-port units when a second device joins); (5) if anything looks wrong, both fall back to safe 5V. This device-in-charge design is why bigger adapters are always safe.
The extensions that matter in 2026
PPS — Programmable Power Supply
Instead of fixed steps, PPS lets the device request voltage in 20mV increments in real time, moving conversion losses from the phone into the adapter. It's mandatory for Samsung Super Fast Charging (the Galaxy trap) and used by Pixel and most fast-charging Android phones. Look for "PPS" plus a range like "3.3–21V".
PD 3.1 / EPR — Extended Power Range
PD originally capped at 100W (20V/5A). PD 3.1 adds 28V, 36V, and 48V rails, taking USB-C to 140W, 180W, and 240W. This is what the Apple 140W and 240W desk units speak — and it requires an EPR-rated cable end to end.
What about Quick Charge?
Qualcomm's legacy protocol. QC 4+ converged with PD, so any modern PD adapter covers old QC devices. Never buy for QC alone; treat it as a free bonus. More in Quick Charge explained.
Reading a charger listing like an engineer
A trustworthy listing states its profiles: "PD 3.0: 5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/3.25A; PPS: 3.3–11V/5A". Red flags: a wattage with no profile table, "supports all protocols" with no list, or peak numbers that only exist single-port. When in doubt, our category pages (USB-C hub) only list units with published, verified profiles.
| Rail | Introduced by | Max current | Ceiling | Typically used by |
|---|---|---|---|---|
| 5V | PD 1.0 | 3A | 15W | Earbuds, watches, safe fallback |
| 9V | PD 2.0 | 3A | 27W | Phones (20W–30W class) |
| 15V | PD 2.0 | 3A | 45W | Tablets, handhelds, Switch dock |
| 20V | PD 2.0 | 3A / 5A | 60W / 100W | Laptops (65W, 100W) |
| 28V | PD 3.1 EPR | 5A | 140W | MacBook Pro 16″ |
| 36V | PD 3.1 EPR | 5A | 180W | Workstation and gaming laptops |
| 48V | PD 3.1 EPR | 5A | 240W | Desk hubs, monitor pass-through |
| PPS | PD 3.0 | variable | rail-dependent | Galaxy Super Fast 2.0, Pixel |
Read the table as a shopping filter. Any adapter's real capability is the highest rail it publishes multiplied by the current it publishes on that rail — a "100W" unit with no 20V/5A row is not a 100W unit. The 5A rows all require an e-marked cable, and the three EPR rows require a 240W-rated one; see e-marked cables. Compare protocols directly at PD vs PPS and PD vs Quick Charge, or browse hardware that implements them at GaN chargers and best USB-C chargers.
FAQ
Do both my charger and phone need to support PD?
Yes, but every USB-C phone, tablet, and laptop since roughly 2018 does. The variable is really the adapter and the cable.
Is PD the same as fast charging?
PD is the standard that enables it. 'Fast charging' is marketing for 'charging near the device's maximum input' — which happens when adapter wattage and protocol both match the device's needs.
What is a PD profile mismatch?
When an adapter technically has enough watts but lacks the voltage step a device wants — e.g. 45W without PPS on a Galaxy Ultra, or 100W without 28V for a MacBook Pro 16″. The fix is matching the extension, not adding watts.