Overview
IEC 63563-5:2025 - Qi Specification version 2.0, Part 5: Communications Physical Layer defines the low‑level communications between a Qi power receiver (PRx) and power transmitter (PTx). Published by IEC in 2025 and based on the Wireless Power Consortium (WPC) Qi v2.0 specification, this standard specifies the physical layer and data link formats for data bits, bytes and packets, and provides requirements and guidelines for load modulation (backscatter) and frequency‑shift keying (FSK) used in wireless power transfer.
Key topics & technical requirements
- Physical & data link layers: Formats and interpretation of data bits, bytes and complete data packets used for PRx→PTx communications.
- Load modulation (backscatter): PRx modulates the power drawn from the primary cell to create two amplitude states (HI and LO). The standard requires detectable amplitude differences; examples in the document include at least 15 mA change in primary cell current or 200 mV change in primary cell voltage. States must be held constant for a minimum specified duration to be valid.
- Frequency‑shift keying (FSK): Defines FSK modulation scheme, bit/byte encoding, and packet structures (see sections on modulation, encoding and response patterns).
- Encoding & packet structure: Big‑endian storage for numeric fields, ASCII printable text strings (0x20–0x7E) padded with NUL (0x00), and shorthand packet mnemonics (e.g., /) for protocol references.
- Compliance language & conventions: Verbal forms (shall/should/may), notation rules for numbers and packet fields, and scope of mandatory vs informative provisions.
Applications & who should use it
- Wireless power system designers (transmitters and receivers) implementing Qi v2.0 communications.
- IC and chipset developers building modulation/demodulation hardware for wireless power.
- Firmware and protocol engineers implementing bit/byte encoding, framing and link‑layer behavior.
- Test labs and conformity assessors validating compliance with Qi communications physical layer requirements.
- Product manufacturers of chargers, mobile devices and accessories integrating Qi wireless power.
Practical value
Adopting IEC 63563-5:2025 ensures interoperable, robust PRx→PTx communications in Qi wireless charging ecosystems. It provides measurable thresholds for reliable detection (current/voltage delta), clear encoding/packet rules, and both load modulation and FSK options - enabling designers to implement interoperable, testable wireless power products.
Related standards
- Qi Specification family (other Qi v2.0 parts such as Communications Protocol, Power Delivery, Mechanical/Thermal documents)
- IEC publications and WPC documents referenced in the Qi specification for interoperability and conformance testing
Keywords: IEC 63563-5:2025, Qi Specification 2.0, Communications Physical Layer, load modulation, frequency‑shift keying, backscatter modulation, wireless power transfer, WPC.