At the iPhone 17 series launch event, Apple did not mention it, but a 40W Dynamic Power Adapter quietly appeared on Apple’s official website, drawing great attention from both industry insiders and consumers. Unlike previous chargers with fixed power levels, this one is labeled as 40W, but with an unprecedented suffix: “with 60W Max.”
This extra 60W is actually enabled by SPR AVS, which was introduced in the USB PD 3.2 specification update of October 2024. SPR AVS defines a standard power range of 27W–100W, allowing devices to precisely negotiate charging needs between 9V and 20V in 100mV steps. This ensures better power conversion efficiency while reducing heat loss.
ChargerLAB has compiled a comparison table of USB PD PPS, ERP AVS, and SPR AVS protocols.
We have also organized a complete USB PD specification document, including the PD 3.2 update, for those who need a detailed reference.
Google Drive: https://drive.google.com/file/d/1jwiU6huqDx5pysulzcXnafnvQbJkG9_Y/view?usp=sharing