A 3.0-W wireless power receiver circuit with 75-% overall efficiency

Resonant magnetic coupling is utilized to transfer 3.0-W power without wire. The received AC power is rectified by an active rectifier and then converted to the desired DC level by a switching DC-DC converter. The reverse leakage of the active rectifier is prevented by a delay locked loop (DLL) based delay compensation circuit. The overall power efficiency of the wireless power receiver implemented in a 0.35-μm BCDMOS technology is 75-% when the resonant frequency of the magnetic resonator is 3.23-MHz.