The Latest Version Of Qi Standard V1.2.4 Comes, Fixed-frequency Voltage Regulator Program

- Mar 08, 2018-

Recently, the WPC Wireless Charging Alliance released the latest Qi standard on its official website with the version number v1.2.4, which will be enforced on March 8, 2018. This means that wireless charging products will need to follow Qi v1.2.4 Standard certification, rather than the previous Qi v1.2.3. With the release of Qi, the latest standard, fixed frequency regulators may benefit.

Regarding Apple's 7.5W transmitter authentication, Qi v1.2.4 has the following updates relative to Qi v1.2.3:

1. The TX type MP-A11 is officially incorporated into the Qi standard in Qi v1.2.4.

2. In Qi v1.2.3, this type of transmitter passes BPP + FOD Extensions authentication. In the newly released Qi v1.2.4, the transmitter authentication level is simplified, and the EPP (MP-A11 ) Certification.

To sum up, after the new agreement is enforced, the type of Qi certification that the 7.5W transmitter of Apple needs to pass is EPP (MP-A11).

Market wireless charging transmitter program interpretation

Wireless charging launchers currently on the market are mainly divided into two categories:

The first type is the low-middle-end transmitter. The scheme adopted is the frequency conversion architecture and the fixed-frequency modulation duty cycle architecture.

The working principle of the frequency conversion architecture is to adjust the transmit power by changing the operating frequency, which may cause some interference to the mobile phone circuit in some transmitting frequency bands. At present, the transmitter of the frequency conversion architecture on the market generally uses A11 or A11a and can only pass BPP certification. These transmitters typically have powers greater than 5W and less than 10W and no Q-value detection circuitry, which is significantly inferior to the FOD (metal foreign object detection) performance over the BPP + FOD Extensions and EPP certified transmitters.

Some transmitters support Apple's 7.5W fast charge on the A11 / A11a basis by adjusting the duty cycle for a fixed operating frequency. The transient response of this architecture is poor. Transmitters based on this architecture generally do not have a Q-detection circuit and will be poor in FOD detection, nor do they comply with EPP requirements or pass EPP certification. Fixed-frequency duty cycle architecture as a Chinese-style innovation, the program wins in the cost-effective, to a certain extent, also allows users to enjoy the lower prices Apple fast charge experience, but can not do zero interference on the phone. More importantly, it does not conform to the MFi specification and does not belong to the standard architecture of Qi, which may not meet the more stringent requirements of fast charge in the future of Apple's mobile phones and are more likely to fail Apple certification in the future.

The second category is to support Apple 7.5W transmitter represented by fixed-frequency voltage regulator architecture.

Fixed-frequency voltage regulator is Apple's official standard program, Apple proposed at the MFi conference 7.5W fast charge is fixed frequency regulator architecture. Using MP-A11 topology, the operating frequency is fixed at about 127KHz, the duty cycle is constant at 50%, and the transmit power is controlled by adjusting the voltage. Can effectively avoid interference with the phone's band, so that wireless charging on the phone to minimize interference. A Q value detection circuit, FOD detection will be more sensitive to meet EPP requirements. The program can be BPP + FOD Extensions and EPP certification. After WPC Qi v1.2.4 is executed, the EPP certification is uniformly assigned. Market fixed frequency regulator program manufacturers representatives: NXP, IDT, and easy red wireless (CPS).

At present, the mass-produced Apple 7.5W transmitter with fixed-frequency voltage regulation structure is known in the market. In addition to Apple's official mophie and Belkin, there are RAVPower, Spigen, Anker and others. The first two use the NXP program, the latter three use the easy punch wireless (CPS) program. NXP as Apple's official supplier of wireless chargers, of course, is the benchmark for fixed-frequency regulators, of course, the cost will be higher. As the leading enterprise in China, Infineon Wireless is the most widely used 7.5W fixed-frequency product and is widely used by first-line brands. As for IDT, it is reported that it has also launched related products in the near future. It is believed that the market will soon enter the next round of competition. Also found in the WPC official website certified product page has updated a mophie second-generation launchers, the transmitter for fixed-frequency voltage regulation architecture, support for Apple 7.5W fast charge, said the program provider from NXP to easy red wireless.

How to choose the brand manufacturers?

First of all, in terms of authentication, the market of mobile phone generally wireless charging power is higher than 5W, generally 7.5W or 10W, so the transmitter program needs to pass Qi v1.2.4EPP certification. Followed by the program, because of the need to focus on charging stability, charging efficiency, FOD, the interference of mobile phones and other aspects of performance, so the Apple 7.5W fast charge the best choice Apple products specified fixed-frequency regulator architecture transmitter program.


Apple's new machine equipped with wireless charging completely detonated the market, followed by LG, Nokia, SONY, Jin, Xiaomi, Huawei and other manufacturers have been or are about to follow up the technology, this wave of overwhelming. It is expected that the release of Qi v1.2.4 version will further standardize the wireless charging market and promote industrial upgrading. The market's Apple 7.5W wireless charging products will be equipped with mainstream fixed-frequency voltage regulation solutions.