Both PPS (Programmable Power Supply) and SPR AVS (Standard Power Range Adjustable Voltage Supply) are advanced fast charging protocols featuring dynamic voltage adjustment capabilities. While both technologies share the concept of adjustable voltage delivery, they differ significantly in technical specifications, design philosophy, and implementation approach.
1. Technical Specifications Difference
PPS
- Introduced with USB PD 3.0
- Voltage range: 3.3V–21V
- Adjustment precision: 20mV voltage steps, 50mA current steps (high precision)
- Mainly for: Phones, tablets, and other small to medium power devices, especially for direct battery charging (common in Samsung and Android phones)
SPR AVS
- Introduced with USB PD 3.2
-
Voltage ranges:
27–45W: 9V–15V
45–100W: 9V–20V - Adjustment precision: 100mV voltage steps (lower precision than PPS, optimized for broader compatibility)
- Mainly for: Devices ≤100W, including phones, iPads, and thin laptops. It brings AVS (previously in EPR for 100–240W) down to the SPR range.
2. Different Design Philosophies
- PPS: Designed specifically for direct battery charging applications, PPS requires extremely fine voltage adjustments (20mV steps) to precisely track the battery's charging curve and minimize conversion losses throughout the charging cycle.
- SPR AVS: Serves as a bridge between traditional fixed-voltage PDOs (Power Delivery Objects) and EPR AVS, extending adjustable voltage capabilities to devices under 100W. SPR AVS prioritizes broad compatibility and operational stability over maximum precision, making it ideal for mainstream consumer devices.
3. User Experience Differences
PPS Experience
Phone manufacturers use it in their fast charging systems. The benefits are faster charging speeds and less phone heating. However, PPS compatibility varies— not all chargers and devices support it.
SPR AVS Experience
Voltage transitions are smoother, less likely to cause power drops or screen flickering, and reduce heating. More importantly, it's a universally supported new capability in the USB PD standard, so mainstream devices like iPhone 17 can directly benefit.
Quick Summary:
PPS = Ultra-precise, born for direct battery charging.
SPR AVS = Universal adjustable voltage, bringing more stable, cooler charging to devices ≤100W.
Practical Comparison: Understanding the Technical Differences
To better understand the distinction between these two protocols, consider the following comparison:
PPS: Precision-Optimized Protocol
PPS functions like a precision instrument, making fine-grained adjustments (20mV increments) to match exact battery requirements. This precision is particularly valuable in direct battery charging applications where optimal voltage matching minimizes energy loss and heat generation.
SPR AVS: Flexibility-Focused Standard
SPR AVS operates with broader voltage adjustment ranges (9-20V) in 100mV steps, prioritizing universal compatibility over maximum precision. This approach provides sufficient flexibility for most devices while maintaining stable operation across diverse charging scenarios.
Important Note!
iPhone 17 supports SPR AVS, not PPS. This is a key distinction that affects charger compatibility and performance!