Wireless Power Transfer relies on magnetic induction between a planar receiver and transmitter coils. When the receiver coil is positioned over the transmitter coil, magnetic coupling occurs when driving the transmitter coil. The resultant flux is coupled into the secondary coil, which induces a voltage and current flows. The secondary voltage is rectified, and power is wirelessly transferred to a load. Two new Texas Instruments ICs manage this transfer: one transmits and the other receives the transferred power, as shown in Fig. 1. The power transfer receiver IC is a bq51050B secondary-side direct li-ion battery charge-controller (Fig. 2).
Fig. 1. Wireless power transfer using receiver and transmitter circuits.