Low-consumption demodulation method for FSK signal in wireless charging equipment

Abstract

The invention relates to a low-consumption demodulation method for an FSK signal in wireless charging equipment. The method is characterized in that a signal on a receiving coil is sent to the input end of a demodulation chip comparator, and comprises the following steps of: (1) sampling an output value of the comparator and acquiring the number of sampled points in a period; (2) demodulating the signal according to the number of the sampled points in the period; (3) synthesizing a complete data frame according to a demodulated result; and (4) verifying and outputting the complete data frame. In the low-consumption demodulation method which adopts the above steps and is used for the FSK signal in the wireless charging equipment, a complex analog circuit is not required, the maximum frequency required by a digital circuit in the method is only 2 MHz, , only a simple addition operation is performed under the frequency, and the main operating frequency is 210 KHz or below; and compared with a conventional FSK decoding method, the method is more suitable for the FSK signal according to the QI standard, the cost is low, the demodulation speed is high, debugging is convenient and the precision is high.

Description

technical field [0001] The present invention relates to the field of electronic technology, in particular to wireless charging, in particular to a low-consumption demodulation method for FSK signals in a wireless charging device. Background technique [0002] In the wireless charging equipment of the QI standard, the communication signal transmitted from the energy transmitter to the energy receiver is transmitted through 2FSK (binary frequency shift keying), and the difference from the traditional 2FSK signal is: the communication according to the QI standard Protocol, different phases of the same system, communication carrier frequency Fop and modulation frequency Fmod are not fixed, and the frequency difference between Fop and Fmod is small. [0003] The wireless charging equipment of the QI standard transmits different powers through energy signals of different frequencies during normal operation, and 2FSK signal communication may occur at any frequency point of the ener...

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Problems solved by technology

[0005] Due to the limitations of the QI standard communication protocol, the difference between the carrier frequency Fop and the modulation frequency Fmod is small. If the traditional method is used for demodulation, the entire system needs very high precision to distinguish different frequencies, whether it is analog or digital. will greatly increase the overhead of the entire circuit

At the same time, the carrier frequency Fop may be any value between 110 and 205KHz in different communication stages of the same system, which greatly increases the overhead of the entire demodulation system

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