Rectifier arbitration in wireless charging systems

An electronic device configured to receive wireless power from a power transmitting device, comprising:

• first and second coils configured to receive alternating-current magnetic signals transmitted from the power transmitting device and configured to produce corresponding alternating-current voltages;
• a first rectifier coupled to the first coil, wherein the first rectifier has transistors configured to rectify the alternating-current voltages from the first coil and produce a corresponding rectified direct-current voltage when active rectification in the first rectifier is enabled;
• a second rectifier coupled to the second coil, wherein the second rectifier has transistors configured to rectify the alternating-current voltages from the second coil and produce a corresponding rectified direct-current voltage when active rectification in the second rectifier is enabled;
• and
• control circuitry including a comparator that has first and second inputs, wherein a first node between the first coil and the first rectifier is coupled to the first input of the comparator, wherein a second node between the second coil and the second rectifier is coupled to the second input of the comparator, and wherein the control circuitry is configured to enable active rectification in at least one of the first rectifier and the second rectifier based on an output of the comparator.