Wireless Power Transmitter

Description

Transmitter board for 5W Wireless Power.

Transmitter module that, combined with a receiver unit 7100-FT1236M, allows the creation of wireless energy transfer systems. The transmitter unit, based on the P9038 IC from IDT, generates an amplified alternating signal applied to an inductor (available separately), whose task is to radiate the electromagnetic field into the surrounding space. The board is able to detect the presence of a load, i.e., a coil in proximity from which energy is drawn, to reduce consumption during phases when energy transfer is not needed. The transmitter module features an 11-pin strip with 2.54 mm pitch, where power can be applied through the Vin and GND terminals, with a voltage between 4.5 and 6.9 VDC.

Dimensions: 31 x 44 mm

Note: The board is supplied fully assembled. The coil for the Wireless Power transmitter is not included and is available separately.

Block Diagram of the IDT P9038 IC

Data Sheet

The Technique

The possibility of transferring electrical energy through electromagnetic waves was first demonstrated in 1890 by Nikola Tesla, who perhaps did not imagine how much it would be appreciated today. The technique is easy, but making this technology more efficient, less bulky, especially for higher powers than the negligible ones available in the past, is the real challenge, which becomes more difficult if solutions must be economical and miniaturized to be introduced even into the smallest devices. IDT (Integrated Device Technology), a California company pioneering this technology, has made available documentation and products to create miniaturized systems to be integrated into the many fields of wireless battery charging.

The Qi Standard

To ensure compatibility between transmitters and receivers, the Wireless Power Consortium (WPC) was created, which established a standard (Qi) ad hoc; this consortium was founded in 2008 and consists of Asian, European, and American companies. The WPC defines the type of inductive coupling, intended as the configuration of the inductors and the communication protocol to be used; in this way, any device that complies with the WPC standard specifications can operate with another standard product even of a different brand, ensuring interoperability and, above all, the availability of power when away from home. The inductors allow, in addition to energy transfer, also the communication channel between receiver and transmitter. The standard defines systems capable of transferring energy without contact, typically with powers up to 5W and distances not exceeding 5mm; the output voltage regulation is achieved through digital control that allows using the communications exchanged between RX and TX to inform the latter of the amount of power required by the load.