Renesas: contactless wireless charging solution for healthcare and wearable devices
Renesas Electronics announced a contactless wireless charging solution for low-power applications, such as hearing aids and other wearable devices that require resistance to water and dust, consisting of a power receiver integrated circuit (IC) (RAA457100) and a power transmitter IC (RAA458100). Each IC includes all functions needed for wireless charging on a single chip. Renesas will also offer an evaluation kit to help manufacturers with their wireless charging designs.
Wireless charging technology eliminates the need to change batteries or connect a power cable. This convenience has wide appeal for a variety of applications, such as smartphones and wearable devices. Wireless charging technology is of particular interest in low-power applications such as hearing aids that require small form factors as well as resistance to water and dust. However, existing wireless charging technologies have been considered unsuitable for charging systems employing compact Li-ion secondary batteries for these low-power applications associated with the difficulties in; achieving smaller form factors with the antenna size mandated by the current standards; and heat dispersion due to large charging currents that are required to charge low-power applications.
With the new wireless charging solution, Renesas has combined its wireless charging system expertise with its proven MCUs to enable all key system components in a small space for easier design implementation.
The μPA2690T1R power MOSFET from Renesas is recommended for configuring the bridge circuit. When it is combined with the RAA458100, the system manufacturer can choose between half-bridge and full-bridge circuit configurations to match the power level of the power transmitter.