Patent ID: 9444290
Filing Date: 2016-09-13
CPC Classification: G06K,H02J

Claim Text:
1. A circuit for signal decoding in RFID (radio frequency identification) or wireless power charging, comprising: an upper switch, which comprises a first terminal, a second terminal and a control terminal, wherein the first terminal of the upper switch is coupled to a power voltage; a lower switch, which comprises a first terminal, a second terminal and a control terminal, wherein the first terminal of the lower switch is coupled to the second terminal of the upper switch, and the second terminal of the lower switch is coupled to a common voltage; an L-C (inductor and capacitor) resonant circuit, which comprises a first terminal, a second terminal and a resonant decoding terminal, wherein the first terminal of the L-C resonant circuit is coupled to the second terminal of the upper power switch and the first terminal of the lower power switch, and the second terminal of the L-C resonant circuit is coupled to the common voltage; a voltage decoding circuit, which is coupled to the resonant decoding terminal of the L-C resonant circuit, for decoding a signal of the resonant decoding terminal to obtain a first feedback data according to a variation of an amplitude of the signal of the resonant decoding terminal; a current decoding circuit, which is coupled between the second terminal of the lower switch and the common voltage, for decoding a current variation of the lower switch to obtain a second feedback data according to the current variation of the lower switch; and a control circuit, which is coupled to the control terminal of the upper switch, the control terminal of the lower switch, the voltage decoding circuit and the current decoding circuit, for decoding the first feedback data and the second feedback data to check whether a check code of the first feedback data is conformed to a specification and whether a check code of the second feedback data is conformed to the specification, wherein the control circuit acquires one of the first feedback data and the second feedback data which is conformed to the specification to serve as a reference for controlling the upper switch and the lower switch, wherein, when the load is heavy such that the first feedback data decoded by the voltage decoding circuit is incorrect, wherein the control circuit confirms that the check code of the first feedback data is incorrect, the control circuit confirms that the check code of the second feedback data is correct to prevent an electrical disconnection with an outside circuit, and wherein, when the load is light such that the second feedback data decoded by the current decoding circuit is incorrect, wherein the control circuit confirms that the check code of the second feedback data is incorrect, the control circuit confirms that the check code of the first feedback data is correct to prevent the electrical disconnection with the outside circuit.