Speaking of wireless power supply, many people may first think of Qi power supply solutions for charging smart phones and tablets. However, Qi power specifications are not fully applicable to miniaturized wearable devices. A wireless power supply solution that meets the requirements of the Qi standard is mainly suitable for wireless power supply with a large battery capacity of 5-15W.

In response to the characteristics and needs of miniaturized wearable devices, Lapis Technology (LAPIS) aims at wireless power supply solutions with power below 3W. Previously, it developed the first-generation wireless power supply chipset “ML763x” with a power of 200 mW. The power of the second generation wireless power supply chipset “ML766x” is as high as 1W.

Wu Juan, senior manager of Rohm semiconductor (Shanghai) Co., Ltd. Technology Center, said that the wireless charging solution of Lapistone Technology is not intended to replace the Qi standard, but to meet the needs of a wider range of wireless charging applications. It is a kind of Qi standard. add.

What pain points does “ML766x” solve?

The output power of the first generation wireless power supply chipset “ML763x” is 200 mW. It is mainly used for wireless power supply of true wireless stereo headsets. However, it is used for charging products with slightly larger battery capacity. The power supply is not enough. Customers need at least power supply Wireless charging solutions above 500mW.

Although the power supply of a wireless power supply solution that meets the Qi standard can meet the requirements, because the physical size of the chipset under the Qi standard is relatively large, it cannot meet the physical size requirements of miniaturized wearable devices. Therefore, it has become an urgent need for customers to find a wireless power supply solution that can increase the power supply and meet the miniaturized physical size.

Wu Juan said that the second-generation wireless charging chipset “ML766x” launched this time has a power supply of up to 1W, while achieving a miniaturized design, which satisfies true wireless stereo headsets, mice, keyboards, wrist blood pressure monitors, hearing aids, and smart watches. And electric toothbrushes and other broader product design needs.

According to Wu Juan, the new product “ML766x” chipset includes two LSIs at the transmitter and receiver. The ML7661 at the transmitter is a 40pin WQFN package, and the ML7660 at the receiver is available in 30pin WL-CSP and 32pin WQFN packages. It satisfies customers to flexibly design small and thin wireless charging products.

Two major features of “ML766x”

For small Electronic devices, the wireless charging solution using Qi standard 15W power supply exceeds the specifications and the area is too large. The new product optimizes the control of the transmission power according to the required power supply, which can suppress the heat generation of the LSI main body and achieve up to 1W wireless power supply.

According to Wu Juan, due to the 13.56MHz high frequency power supply, the antenna size can be smaller. Compared with ordinary products, the system size can be reduced by 30%, so it is very suitable for small electronic devices such as wrist blood pressure monitors, smart watches, and hearing aids.

In addition, built-in support for I2C interface and SPI interface communication protocol, in addition to high-speed communication, you can also connect multiple slaves; built-in control circuit required for power transmission and reception, without the need for a microcontroller to control digital sensors equipped with these functions, etc. . In this way, the installation space of the microcontroller can be reduced. Even compared with ordinary products with the same 1W power supply, the system size of the new product in the industry is also ultra-small.

Another feature of “ML766x” is that it has both functions of wireless power supply and NFC contactless communication.

NFC wireless communication uses 13.5MHz near field communication technology, while “ML766x” wireless power supply uses the same 13.5MHz frequency.

The current common solutions on the market require two sets of antennas, one set for power supply, and one set for communication if they want to communicate and supply power at the same time. The “ML766x” of Lapistone Technology can reuse the same frequency with wireless communication through wireless charging, and realize the two functions of wireless power supply and wireless communication at the same time with only one antenna. At the same time, the typical mode of NFC also consists of three communication modes—card reader mode, card simulation mode, and point-to-point mode. A new wireless power supply mode is added, which becomes four modes.

As a new generation wireless power supply solution for small electronic devices,“ML766x” will achieve mass production in April 2022, and the initial mass production scale will reach 100,000 pieces per month.In order to facilitate users to import and verify, Lapistone Technology has prepared an evaluation board with an open line.

In the future, Lapistone Technology will develop wireless charging solutions with more power specifications based on customer needs, and strive to develop a new generation of products that meet the “NFC Forum” standards as soon as possible, greatly improving the wireless charging applications in various products.

Link to this article：LAPIS second-generation wireless power supply chipset “ML766x” power up to 1W