A system includes a tank circuit, a synchronization circuit, a transmitter, and a control circuit. The tank circuit is configured to receive a first signal transmitted from a near field communication reader. The synchronization circuit is configured to synchronize a clock to the first signal. The transmitter is configured to transmit data using the clock from the tank circuit to the near field communication reader using active load modulation. The control circuit is configured to disable the synchronization circuit during a modulation period of the active load modulation and to reduce energy remaining in the tank circuit at an end of the modulation period.