Apple's 40W Dynamic Power Adapter represents a significant advancement in charging technology, featuring USB PD 3.2 SPR AVS (Standard Power Range Adjustable Voltage Supply) protocol support. This compact charger enables iPhone 17's fast charging capabilities through precise voltage regulation, delivering up to 40W of power with enhanced efficiency compared to traditional fixed-voltage chargers.
USB PD 3.2 SPR AVS Technology Specifications
The adapter implements SPR AVS (Standard Power Range Adjustable Voltage Supply) technology, providing voltage regulation in 100mV increments within the 3.3V-21V range. Unlike traditional Power Delivery Objects (PDOs) with fixed voltage levels, SPR AVS enables real-time voltage negotiation between the charger and device, optimizing power delivery throughout the charging cycle.
Technical Specifications
- Power Output: Up to 40W (20V @ 2A)
- Voltage Range: 3.3V - 21V (SPR AVS)
- Voltage Increment: 100mV steps
- Protocol Support: USB PD 3.2, SPR AVS, PPS
- Connector: USB-C
- Efficiency: >90% at typical loads
This precise voltage control reduces conversion losses within the device, minimizes heat generation, and extends battery cycle life by providing optimal charging voltages during different battery states. The technology is particularly beneficial during the constant voltage phase when the battery approaches full capacity.
iPhone 17 Compatibility and Performance
The iPhone 17 series requires SPR AVS-compatible chargers to achieve maximum charging speeds. While the device supports standard USB PD charging, SPR AVS protocol enables up to 30% faster charging during the initial charging phase (0-80%) compared to traditional fixed-voltage charging methods.
Charging Performance with iPhone 17
- • 0-50% in approximately 25 minutes
- • 0-80% in approximately 45 minutes
- • Optimized thermal management during fast charging
- • Enhanced battery longevity through precise voltage control
Key Features of SPR AVS Technology
- 100mV voltage increments for precise power regulation
- Real-time voltage negotiation with compatible devices
- Reduced conversion losses and improved thermal performance
- Backward compatibility with standard USB PD devices
Purchase Recommendations and Alternatives
The Apple 40W Dynamic Power Adapter is currently available through Apple's official channels and authorized retailers. While Apple was among the first to implement SPR AVS technology, several third-party manufacturers now offer compatible chargers with similar specifications.
Who Should Buy This Charger?
- iPhone 17 series owners seeking maximum charging speeds
- Users prioritizing battery longevity and thermal management
- Those requiring a compact, travel-friendly 40W charger
Alternative Options
Consider these alternatives if the Apple charger doesn't meet your needs:
- • Higher Power Needs: Look for 65W+ SPR AVS chargers for laptops
- • Budget Considerations: Third-party SPR AVS chargers starting around $25
- • Multi-Port Requirements: Chargers with multiple USB-C ports supporting SPR AVS