Near field rf communicators and near field communications enabled devices

摘要

A near field RF communicator has an inductive coupler (10) to enable inductive coupling with a magnetic field of an RF signal. A demodulator (102) extracts modulation from an inductively coupled magnetic field. An error amplifier (206) controls a voltage of the near field RF communicator on the basis of a comparison of a reference voltage (VREF) with a voltage (VINPUT) related to a voltage derived by a power deriver (105). A modulator (M) is provided to modulate an inductively coupled magnetic field with data to be communicated via the inductive coupling. An error amplifier controller (102A; 101) is provided to prevent operation of the error amplifier in the event of a magnetic field amplitude below a predetermined level or the presence of modulation. The near field RF communicator may be a near field RF transponder or an NFC communicator in target mode.