Patent ID: 9515702
Filing Date: 2016-12-06
CPC Classification: H03D,H04B

Claim Text:
1. A demodulator for near field communication (NFC), the demodulator comprising: a scale down circuit configured to receive a first modulated signal and a second modulated signal from a first power electrode and a second power electrode, respectively, and configured to provide a scale down signal to a first node by scaling down a magnitude of the first modulated signal and a magnitude of the second modulated signal; a current source coupled between the first node and a ground voltage, and configured to generate a constant current flowing from the first node to the ground voltage; a charge store circuit coupled between the first node and the ground voltage, and configured to perform a charge operation and a discharge operation alternately, based on the scale down signal and the constant current, to output an envelope signal, which corresponds to an envelope of the scale down signal, through the first node; and an edge detector configured to generate input data, which correspond to the first modulated signal and the second modulated signal, based on a transition of the envelope signal.