PMA standard targeted wireless power charging device's frequency modulation signal demodulating method

Abstract

The invention relates to a PMA standard targeted wireless power charging device's frequency modulation signal demodulating method, comprising: 1) reading wire coil signals; sampling the wire coil signals; and counting the cycles; 2) extracting the frequency changes based on the change of the counted cycles; 3) determining and outputting data according to the frequency changes and the duration of the frequencies; and 4) splicing and outputting the data. With the method, the demodulation part does not require a complicated simulation circuit and the highest frequency required by its digital circuit part is only 4MHz at which only simple adding operation is performed. The main working frequency is under 236KMz. Compared with the current FSK decoding method, the method can be more consistent with PMA standard demodulation signals. With a lower cost yet higher demodulation speed, the method is also convenient to debug and does not have requirement on the fixing of Fop or not. With high precision to be achieved, the method can be applied more widely.

Description

technical field [0001] The present invention relates to the technical field of wireless charging, in particular to the technical field of wireless charging equipment communication, and specifically refers to a method for demodulating a frequency modulation signal of a wireless charging equipment according to the PMA standard. Background technique [0002] For PMA standard wireless charging equipment, when the energy transmitter (TX) sends the FSK signal, it is often at the beginning of the operation of the entire system, and at this time the working frequency of the TX signal is 215-220KHz in the PMA-3 system, and in the PMA-4 system. In the PMA-5 system, it is 142~158KHz, in the PMA-6 system, it is 109~121KHz, in the PMA-7 system, it is 140~158KHz, in the PMA-8 system, it is 220~226KHz. Fmod is Fop+Mdepth, then it can be calculated that the period difference Top-Tmod between the carrier frequency Fop and the modulation frequency Fmod is 96-770 ns. A data is sent every 500u...

AI Technical Summary

Problems solved by technology

[0003] In the wireless charging equipment of the PMA (Power Matters Alliance) standard, the communication signal transmitted from the energy transmitter to the energy receiver is transmitted by means of frequency conversion, and the existing problems are: in PMA-3, PMA-4 , PMA-5, PMA-6, PMA-7, PMA-8 standard communication protocol, the communication carrier frequency Fop of the signal sent by the energy transmitter (TX) is not unique (109KHz≤Fop≤226KHz), and Fop and Fmod The frequency difference between them is not fixed, there is only a certain range of frequency difference, that is, the modulation depth Mdepth (5 ~ 10KHz), and the same power receiving system may need to support the above six kinds of energy transmitters based on different PMA protocols at the same time (TX ),

[0005] Due to the limitations of the PMA standard communication protocol, the difference between the carrier frequency Fop and the modulation frequency Fmod is fixed within a certain range, so that the higher the frequency of Fop, the smaller the period difference between Fop and Fmod. If the traditional method is used for demodulation , the whole system needs very high precision to distinguish different frequencies, no matter using analog or digital way, the time will greatly increase the overhead of the whole circuit

At the same time, the carrier frequency Fop in the communication phase of different PMA transmission systems is not fixed at a certain value between 110 and 205KHz (the PMA protocol only provides a range), which greatly increases the overhead of the entire demodulation system

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