Qi 2.3.1 introduces several important updates that improve the compliance and certification process. Instead of relying on generic testing, certification is now more closely aligned with the actual capabilities of the device being tested.
Key updates include:
These changes make compliance requirements clearer, improve testing accuracy, and help product developers achieve a smoother certification experience.
Qi 2.3.1 introduces the Electronic Self Declaration File (ESDF), a JSON-based file that describes a device and its supported features. Testing tools can automatically read this information and choose the right tests. This reduces manual setup effort and improves consistency across labs and development teams.
The following examples illustrate the ESDF creation in the Compliance Software Application.
Figure 1: Creating Sample ESDF using Pre-compliance mode in MPP-TPR Compliance Test Software
Figure 2: Sample eSDF File Loaded in Compliance Mode – MPP-TPR Compliance Test Software
ESDF Benefits:
Qi 2.3.1 introduces separate compliance tests for each supported power mode. This makes it easier for engineers to identify and run only the tests that apply to their product. Wireless charging devices operate at different power levels, from basic charging to fast charging up to 25W. Since one hardware setup cannot efficiently support all power levels, different power modes are used. Testing each power mode separately improves accuracy and simplifies certification.
The Qi MPP specification introduces different power modes to:
By dynamically selecting the appropriate mode, the system can deliver power more efficiently while maintaining safety and compliance requirements.
Different devices support different charging capabilities. Dedicated tests ensure products are validated only against the features they support. This improves efficiency while ensuring accurate compliance results and better coverage of supported functions.
Before diving into the specifics of each Power Mode, it is helpful to understand how they compare in terms of operating range, purpose, and system behavior. Although the Qi MPP specification defines multiple modes, they are not isolated operating states. Instead, they work together to enable efficient, reliable, and scalable wireless power delivery across a wide range of charging scenarios. The following table provides a high-level comparison of the five Power Modes and their primary roles within the Qi MPP ecosystem.
| Power Mode | Typical Power Range | Primary Purpose | Key Characteristics | Typical Use Case |
| DPM | Legacy Qi operation | Backward compatibility | Supports earlier Qi devices | Legacy receivers |
| LPM | Up to ~5W | Low-power charging | High efficiency at light loads | Low-power devices |
| NPM | ~4.5W-20W | Standard charging | Balanced efficiency and thermal performance | Most smartphone charging |
| HPM | Up to 25W | Fast charging | Optimized for higher power transfer | Fast charging |
| CPM | Full range | Continuous operation | No interruption during transitions | Automotive/fixed-power systems |
Figure 4: MPP-TPR Compliance Test Software displays the “LPM+NPM+HPM” applicable tests when “LPM+NPM+HPM” is selected as the Supported Power Mode in the eSDF
Figure 5: MPP-TPR Compliance Test Software displays the “CPM” applicable tests when “CPM” is selected as the Supported Power Mode in the eSDF
Another important Qi 2.3.1 compliance update is the addition of more negative-case coverage.
Nominal testing verifies that products behave correctly when valid messages and valid operating conditions are present. Interoperability problems, however, often appear under less ideal circumstances. The device may receive an unsupported protocol version, a message may contain unexpected information, a transition may occur at a boundary condition, or the receiver or transmitter may need to reject, ignore, or recover from an invalid condition.
Negative testing validates these behaviors. This is particularly important in wireless charging because compliance involves interaction between products developed independently. A robust Qi device must not only understand valid communication; it must also respond predictably when communication does not follow the expected path.
Qi 2.3.1 places greater focus on validating FSK (Frequency Shift Keying) communication between the transmitter and receiver. The certification process now checks not only whether a device responds correctly, but also whether the transmitted packets follow the required protocol rules.
Key focus areas:
This ensures that devices are not only functional but also fully compliant with Qi communication requirements.
The Qi 2.3.1 compliance suite includes new and removed tests across MPP PTX, BPP/EPP PTX, MPP PRX, and other PRX compliance areas. New coverage includes areas such as SGC, FSK modulation, guaranteed-power behavior, MSN response timing, protocol negative cases, and Foreign Object Detection behavior.
Learn more about Qi 2.3.1 Key Protocol and Power-Management Changes.
When migrating to Qi 2.3.1, teams should focus on tests that validate new or changed product behavior, not just the increase in test count. Some additional tests are simply the result of test suite reorganization. Others verify new protocol features that may require firmware or control logic updates. Identifying these tests early helps ensure a smoother and more efficient migration process.
Early preparation is key to a smooth Qi 2.3.1 certification process. Instead of waiting until formal certification, teams should define product capabilities and begin validation during development. This helps identify issues such as missing SGC support, incorrect MSN behavior, timing mismatches, or unsupported error handling. Using the same test selection logic as the certification process reduces surprises later. The goal is to make certification a final confirmation of compliance rather than the first complete validation of the product.