Wirable power is also wireless power supply, ROHO is 1W power transmission / power receiving chipset -Product & Service: Nikkei Crostek Active

　Rohm's subsidiary Lapis Technology released a news release on the release of a wireless power supply chipset capable of power supply of up to 1W. It consists of a transmitter IC and a receiver IC. The feature is that the mounting area of ​​the power receiving substrate is as small as 230mm². It is aimed at wearable devices. Specific applications include wristband blood pressure monitors, smart watches, and hearing aids.

Wireless power supply chipset capable of power supply of up to 1W (source: ROHM)[Click image to enlarge]

Currently, the Qi standard is widely used in wireless power supply. However, according to the company, "Although the Qi standard can supply a large amount of power at a maximum of 15 W, the mounting area of ​​the power receiving board on which the antenna and power receiving circuit are mounted is large, making it difficult to install in wearable devices." . On the other hand, the new product has the industry's smallest mounting area in the 1W power supply class. The mounting area can be reduced by about 30%.” (ROHM). In addition to eliminating the need for an external microcomputer by integrating a control circuit into the power receiving IC, the antenna was made smaller by adopting a high feeding frequency of 13.56MHz.

Comparison of wireless power supply technology We compared the Qi standard, competitors' products (general products), and the new product "ML766x". Compared to the Qi standard, the maximum power supply amount is smaller, but the mounting area (system size) of the power receiving board can be reduced by about 65%. (Source: ROHM) [Click image to enlarge]Comparing the mounting area of ​​the power receiving board. The right is the case when using this new product. The mounting area (system size) of the power receiving board can be reduced by approximately 30%, and at the same time, the maximum power supply amount can be doubled. (Source: ROHM) [Click image to enlarge]

In addition, since the power supply frequency of the new product is 13.56 MHz, contactless data communication using the short-range wireless communication standard "NFC (Near Field Communication)" is possible. It has the advantage of being available. In the case of an electrically assisted bicycle (E-bike), the data detected by the torque sensor can be transmitted contactlessly while supplying power. "Using wires for power supply and data communication spoils the design. Using the new product eliminates the need for wires and improves design and design flexibility," said the company.

　The model number of the power transmission IC released is "ML7661", and the power reception IC is "ML7660". The power transmission IC includes a power transmission control circuit, an NFC communication control circuit, an SPI/I²C interface, and a 10-bit A-D converter. The power receiving IC includes a power receiving control circuit, NFC communication control circuit, SPI/I²C interface, 496-byte data flash memory, and a 10-bit A-D converter. The data transmission speed of NFC communication can be selected between 212kbit/s and 424kbit/s. The power transmission IC package is a 40-pin WQFN with external dimensions of 6.0mm x 6.0mm x 0.8mm. For the power receiving IC, we have prepared a 30-terminal WLCSP with external dimensions of 2.28 mm × 2.61 mm × 0.48 mm and a 32-terminal WQFN with external dimensions of 5.0 mm × 5.0 mm × 0.8 mm. Both have an operating temperature range of -40 to +85°C.

　Sample shipments of both the power transmission IC and the power reception IC have already started. Mass production is planned to start in April 2010 with a monthly production system of 100,000 units. The sample price is 550 yen (including tax) for both the power transmission IC and the power reception IC.