Demodulation circuit of fsk signal in wireless charging equipment

Abstract

The invention relates to a demodulation circuit for FSK signals in wireless charging equipment, which includes a receiving coil, a comparator, a first low-pass filter, a high-frequency sampling module, a period point counting module, a second low-pass filter, and a period point counting module. The processing module and demodulation output module are connected in sequence to output FSK signals that meet the requirements. The demodulation circuit of the FSK signal in the wireless charging device using this structure uses the method described in the above-mentioned period point calculation module and period point processing module in the demodulation circuit, so that only 2M clock processing is used in the demodulation circuit. data, the packet error rate can be controlled within the allowable range, which greatly reduces the hardware circuit overhead, saves resources, and has a wide range of applications.

Description

technical field [0001] The present invention relates to the field of electronic technology, in particular to wireless charging, in particular to a demodulation circuit for FSK signals in a wireless charging device. Background technique [0002] The wireless charging equipment using the Qi standard transmits power through 2FSK (binary frequency shift keying). A single-frequency sinusoidal signal, but may be doped with a large amount of high-frequency noise. At present, because wireless charging technology is in its infancy, there are not many FSK signal demodulation circuits for Qi standard wireless charging equipment. The existing FSK demodulation circuits are all for ordinary FSK signals. The traditional 2FSK demodulation method mainly There are three ways of coherent demodulation, filtering non-coherent demodulation and quadrature multiplication non-coherent demodulation. [0003] In the Qi standard communication protocol, in order to ensure the stability of the transmis...

AI Technical Summary

Problems solved by technology

If the traditional method is used for demodulation, the whole system needs very high precision to distinguish different frequencies, which will greatly increase the overhead of the whole circuit no matter whether it is analog or digital.

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 circuit

[0004] Therefore, in the prior art, the demodulation problem of the FSK signal of the wireless charging device of the Qi standard is realized by a hardware circuit

Images