Talking about wireless charging development and solutions

The three common ways of wireless charging are as follows. As can be seen from the figure, the electromagnetic induction type is currently the most efficient and smallest, and is most suitable for use in portable devices.

Although the wireless charging technology is simple in principle and can be understood with primary physics knowledge, there are still many technical problems that need to be solved in terms of product application. There are currently two major wireless charging technologies on the market: one is WPC and the other is A4WP.

In order to promote the development of wireless charging technology, on December 17, 2008, several companies such as Philips Electronics, Texas Instruments, and National Semiconductor jointly established the Wireless Charging Alliance WPC to jointly develop a wireless charging standard Qi to improve the compatibility of different products. Qi uses the most mainstream electromagnetic induction technology. On August 31, 2010, the Wireless Charging Alliance announced in Beijing that it has officially introduced the international standard for wireless charging in China. Currently, 109 companies have participated in the alliance. Among the WPC Alliance members, the mobile phone industry is the first to join, including Samsung, Huawei, Nokia, Blackberry and so on.

Texas Instruments (TI), one of the major WPC members, introduced the industry's first wireless power transmission control chipset. The set consists of a bq500110 single-channel transmit control chip and a bq51013 single-channel receive control chip. TI's wireless charging solution, the transmitter has 19V power supply and 5V power supply. Currently, the wireless charging kits on the market are basically non-5V power supply, such as 12V, 19V. The convenience of use will be affected. A dedicated power supply is needed to power him. The adapter for the mobile phone and the USB port of the computer cannot supply power to it. . TI is the first mass production wireless charging solution company.

TI's wireless charging development board

At the beginning of May this year, Qualcomm, a supporter of magnetic resonance technology, teamed up with Samsung and Powermat to form the wireless charging alliance A4WP, which mainly promotes magnetic resonance technology. A4WP's wireless charging technology not only supports free placement, but also supports charging multiple devices at the same time.

IDT Corporation (Integrated Device Technology, Inc.) develops an integrated transmitter and receiver chipset based on resonant technology for Intel's wireless charging technology.

Convenience is one of the key factors driving consumer mobile solutions to adopt wireless technology first. Different mobile devices, such as mobile phones, tablets, media players, and mobile TVs, require various adapters for different interface connectors, which means that in order to charge mobile devices, people need to carry many different connectors and adapters. These needs can be addressed with a universal wireless adapter with a strong supporting infrastructure and ecosystem. Providing wireless charging in cars, coffee shops, libraries, restaurants, trains, airplanes, and offices will satisfy the convenience people need.

IDT's wireless charging solution

Although wireless charging technology can be used in mobile phones, notebook computers, small appliances, etc., the market share is still the largest in the mobile phone field. The wireless charging technology trend is summarized as follows:

First: the simple principle The principle of electromagnetic coupling of high school physics, the industry is also very familiar, the technology extended from RFID is also very easy to accept. The receiving end is one or two chips (finally a single-chip solution), one end is connected to the charging coil, and one end is connected to the battery. Many companies have begun to introduce a series of chips, which will accelerate the spread and popularity of wireless charging knowledge.

Second: the extra space in the troublesome craft mobile phone, especially the smart phone, is difficult to vacate to place a large charging coil.

as the picture shows:

This circular coil with a diameter of 40mm, plus a thickness of 0.8-2mm inorganic magnetic material (that is, the use of micro-aeronautical organic magnetic material should also be 0.2mm thickness), the thickness of the mobile phone should be increased, if this component is placed on the mobile phone circuit board It also takes up space and runs on other components. Therefore, all engineers who do mobile phone structural design have headaches, which restricts or hinders the development of wireless charging products. Become a roadblock.

Some companies have introduced wireless charging and receiving coils (antennas) with a thickness of 0.53mm, which is expected to promote the popularization of wireless charging technology in mobile phones.