USB-C PD and PPS
PD sets the ceiling, PPS sets the smoothness, and the cable decides whether either reaches the phone.
This is the protocol half of the charging topic. Work down through what the versions actually change, what PD and PPS each do differently, and the cable and connector rules that decide the real outcome.
- Three routes below cover every protocol decision
- 29 guides organised by the question they answer
- Every route ends at a version, a voltage range and a cable rating
Three routes, and you only need one of them
Learning the protocol, tracking the versions and choosing between PD and PPS are three different jobs. Start with the one you are actually doing.
Learn the protocol first
PD is a negotiation, not a voltage. Understanding what is being agreed — and by whom — makes every version change easier to read.
Track the versions
3.0, 3.1 and 3.2 change the voltage ladder rather than the connector. Knowing which tier a design needs stops you paying for headroom nobody will use.
Decide PD or PPS
Both can charge the same phone and they do not deliver the same result. PPS matches the battery curve; fixed PD runs in steps. Which one your line needs depends on the device list.
The cable and connector are part of the protocol
A protocol negotiation sits on top of a physical link. If the link cannot carry the current or hold the contact, the negotiation result is irrelevant.
Cables and E-markers
Above 3A the cable has to identify itself with an E-marker chip, and without one the system negotiates down regardless of what the charger advertises. Voltage drop over a long or thin cable does the rest: the phone sees a lower voltage and compensates with more current, which shows up as heat rather than speed.
Connector durability
The connector is the part that wears out, and its rating is a test result rather than a design intention. Insertion cycle data belongs in the specification for any product with a captive cable or a fixed receptacle.
High power: 140W, 240W and the wall behind them
Above 100W the constraint stops being the charger and becomes the cable, the connector and the circuit the socket is on.
The 140W tier
140W is where EPR becomes the default rather than a feature, and where multi-port allocation gets hard. Two 140W platforms on paper can behave completely differently once three devices are plugged in, so the split map is part of the platform comparison.
240W and the socket
A 240W charger is only a 240W charger on a circuit that can feed it, and most domestic sockets shared with other loads cannot. The honest specification for this tier includes the supply conditions, not just the output.
Building and certifying a PD line
Once the protocol choice is fixed, the remaining work is platform standardisation and the compliance path that lets the product ship.
Fixed-plug OEM platforms
A fixed-plug platform lets one internal design serve several markets by changing the plug assembly rather than the electronics, which is what keeps certification cost proportional to volume. It is the single most useful decision in a PD line.
Fleet and port-layout configurations
In a business fleet the port layout matters more than the peak rating, because the total is shared and the split policy decides which device gets throttled. Specify the map, not just the wattage.
Certification
PD certification is what proves the negotiation behaviour to a customer or an auditor, and it sits alongside the regional safety marks rather than replacing them.
What actually decides whether a PD charger delivers
Four things, in this order. The version number on the box is the least useful of them.
The negotiated profile
A charger advertising 100W only delivers it if the device asks for a profile the charger can supply. Mismatched profile support is the most common reason a capable brick charges slowly.
The cable E-marker
Above 3A the cable must identify itself. Without an E-marker the negotiation caps out, and no amount of charger headroom changes that.
Voltage drop in the cable
A long or thin cable loses voltage, the device draws more current to compensate, and the loss appears as heat rather than speed. Cable quality is a charging specification, not an accessory choice.
Port allocation on multi-port units
The total is shared. Whether the laptop keeps its fast-charge window when three other devices are plugged in depends entirely on the documented split map.
Where to go from here
The protocol cluster connects to four neighbours. Pick the one that matches your next question.
USB-C PD and PPS questions
The short answers. Each one links into the guide that covers it properly.
Is PPS better than PD?
Not better, different. PPS lets the charger follow the battery curve in fine steps, which keeps the phone in its efficient window and runs cooler. Fixed PD charges in voltage steps. For phones that support PPS it is the better path; for everything else plain PD is the standard answer.
What does PD 3.1 actually add?
EPR, which extends the voltage ladder above 20V and makes 140W and 240W over USB-C possible. Below 100W, PD 3.0 and 3.1 behave almost identically, so the version matters most in the high-power tiers.
Do I need an E-marked cable for 100W?
Yes for anything above 3A. The E-marker is what tells the system the cable can carry the current. Without it the negotiation caps below the charger rating, and the product never reaches the number on its own box.
Why does my laptop charge slowly on a 100W charger?
In order of likelihood: a cable without an E-marker, a port that shares its allocation with another device, a proprietary charging path the brick does not speak, or a profile the laptop will not accept. Test the cable first, then the port map.
Is a 240W charger worth specifying?
Only if the machines genuinely draw that much and the socket can feed it. Above 100W the constraint moves to the cable, the connector and the circuit, so a 240W output figure without those conditions is an incomplete specification.
Request a protocol review
Send us the device list and the wattage tiers you are working to. We will come back with the versions and profiles each device needs, the cable rating that supports them, and the platform choice that keeps certification cost proportional to volume.