Apple Inc.
Wireless charging device with multi-tone data receiver and active power supply noise cancellation circuitry

Abstract:

A wireless power transmitting device transmits wireless power signals modulated at a given power frequency to a wireless power receiving device using a wireless power transmitting coil. The wireless power receiving device may transmit data signals to the wireless power transmitting device. The wireless power transmitting device may include a data receiver that is coupled to the wireless power transmitting coil and that receives the transmitted data. The data receiver may include an input stage, bandpass filter circuitry, demodulator circuitry, and a data stream combiner. The data receiver may further include a power supply noise cancellation circuit. The power supply noise cancellation circuit may include an input stage, a baseband filter, a window filter, a down-sampler, and a difference filter. The power supply noise cancellation circuit may be coupled to the data stream combiner and is configured to mitigate power supply noise interference in the received data.