Understanding USB Power Delivery (PD) is the magic behind fast and versatile charging over that ubiquitous USB-C port. It allows devices from tiny earbuds to powerful laptops to negotiate and receive optimal power from a compatible charger. However, the USB PD standard isn’t monolithic; it has evolved with versions like USB PD 3.0 and the significantly more powerful USB PD 3.1, along with optional protocols like PPS (Programmable Power Supply).
Understanding these different standards is key to maximizing charging speeds, ensuring compatibility, and getting the most efficiency out of your USB-C gear. This MTI Software guide breaks down the technical differences between PD 3.0 and PD 3.1 (including EPR), and explains exactly what PPS brings to the table.
Recap: USB Power Delivery (PD) Basics
Before comparing versions, let’s recall what USB PD does. It’s an intelligent charging specification that facilitates communication between a power source (like a wall charger or power bank) and a power consumer (like a laptop or smartphone) via the USB-C connection. This negotiation determines the optimal voltage and current the device can safely accept, allowing for much higher power levels (wattage) than older USB standards and ensuring safety. For PD to work, the charger, device, and often the cable must all support the standard.
USB PD 3.0: The Established Standard (Up to 100W)
For several years, USB PD 3.0 was the prevailing standard for higher-power USB-C charging.
- Power Limit: Capable of delivering up to 100 Watts (typically at 20 Volts and 5 Amps).
- Fixed Voltages: Primarily worked with fixed voltage steps (Power Data Objects or PDOs), commonly including 5V, 9V, 15V, and 20V. The device would negotiate for the highest voltage it supported at the required current (up to 3A or 5A, depending on cable/charger).
- Adoption: Became widely adopted in laptops, tablets, phones, and chargers, establishing USB-C as a viable laptop charging solution for many models.
The Leap Forward: USB PD 3.1 & Extended Power Range (EPR)
Announced in 2021, USB PD 3.1 represented a major upgrade specifically designed to push power delivery well beyond the 100W ceiling.
- Extended Power Range (EPR): This is the defining feature of PD 3.1. It allows for power delivery up to 240 Watts, making USB-C viable for even more demanding devices.
- New Fixed Voltages: To achieve higher power, PD 3.1 introduced three new fixed voltage levels in addition to the PD 3.0 levels:
- 28V (allowing up to 140W at 5A)
- 36V (allowing up to 180W at 5A)
- 48V (allowing up to 240W at 5A)
- Adjustable Voltage Supply (AVS): Within the EPR range (>100W), PD 3.1 also includes AVS, which allows the device to request fine voltage adjustments (in 100mV steps) from the charger between 15V up to the maximum available fixed voltage (28V, 36V, or 48V).
- EPR Requirements: To actually use power levels above 100W, you need full EPR compatibility: an EPR-capable charger, an EPR-rated cable (specifically marked as supporting 240W or 5A/48V), and an EPR-capable device.
- Backward Compatibility: PD 3.1 chargers and cables are backward compatible with PD 3.0 devices; they will simply negotiate power using the older standard’s limits (max 100W).
Unpacking Programmable Power Supply (PPS)
Distinct from the maximum power capabilities defined by PD versions, Programmable Power Supply (PPS) is an optional standard incorporated within USB PD (starting around PD 3.0 and included in 3.1) focused on charging efficiency and optimization.
- What it Does: PPS allows the connected device to request small, real-time adjustments to both voltage and current from the charger. Standard PD largely works with fixed voltage steps, while PPS allows for much finer control (typically in 20mV voltage and 50mA current increments). This negotiation happens frequently (e.g., every 10 seconds).
- The Benefits:
- Improved Efficiency: By allowing the charger to output a voltage closer to what the device’s battery actually needs at that moment, less power conversion (and thus energy loss as heat) needs to happen inside the device.
- Reduced Heat Generation: Less energy wasted means less heat buildup within the phone or laptop during charging, which is better for the components.
- Optimized Charging Speed & Battery Health: Cooler, more efficient charging can potentially contribute to longer battery lifespan. For specific devices, PPS is required to unlock their fastest possible charging speeds (e.g., Samsung’s “Super Fast Charging 2.0”).
- Compatibility is Key: Both the charger and the device must explicitly support PPS for it to function. Many modern Android flagship phones (especially Samsung and Google Pixel) utilize PPS for maximum charging rates. Check your device and charger specifications for “PPS” support.
PD 3.1 (EPR) vs. PPS: Key Differences
It’s crucial to understand these are not mutually exclusive but address different aspects:
- PD 3.1 (with EPR): Defines the maximum potential power the system can deliver (up to 240W). It’s about enabling high-power charging for demanding hardware.
- PPS: Defines a method for optimizing the charging process itself (efficiency, heat) through dynamic voltage/current adjustments. It can operate at various power levels (not just high power) as long as both device and charger support it.
You can have a PD 3.0 charger with PPS, or a PD 3.1 charger without PPS (though many higher-end PD 3.1 chargers include it).
How to Check for Support
- Chargers: Look at the specifications printed on the charger or its packaging/manual. It should explicitly state “PD 3.0,” “PD 3.1,” “EPR,” and/or “PPS” if supported. Wattage rating is also key.
- Cables: Standard USB-C cables support up to 60W. For 100W charging (PD 3.0), you need a cable rated for 5A, usually with an internal “E-Marker” chip. For EPR (>100W / up to 240W), you need a cable explicitly rated and marked for 240W (or 5A/48V).
- Devices: Check the manufacturer’s specifications for your laptop, phone, or tablet. Look for mentions of maximum charging wattage, required PD version, and whether PPS is supported/required for fastest charging.
Conclusion
The USB Power Delivery standard has significantly advanced, offering incredible charging flexibility via USB-C. While USB PD 3.0 established the foundation up to 100W, USB PD 3.1 with Extended Power Range (EPR) pushes the boundary to 240W for highly demanding devices. Separately, the Programmable Power Supply (PPS) protocol offers a smarter, more efficient way to charge compatible devices (especially smartphones) by reducing heat and optimizing power delivery in real-time. This makes it even more important regarding understanding USB Power Delivery (PD)
Understanding these standards helps you choose the right chargers and cables to safely and efficiently power your devices, ensuring you leverage the full capabilities of USB-C charging. Always check the specifications of your charger, cable, and device to ensure compatibility for the best experience.
Need help figuring out wattage? See... Confused about cables? Check [Link to: USB-C Cable Guide: Decoding Standards…]. For the big picture, visit The Ultimate Guide to USB-C...