wireless charging technology-EPC,PMA,A4WP
Due to emergence, availability and consumption of wireless electronic devices; various standards and technologies have been developed for wireless charging need. They are Qi, EPC, PMA, WPC etc.

Following table summarizes all these wireless charging technologies. The table mentions major difference between these standards comparing various factors such as frequency of operation, coupling factor, cost, metal, form factor, efficiency etc.
Specifications | EPC | PMA | A4WP |
---|---|---|---|
Frequency of operation | 100 to 205 KHz | 250 to 400 KHz | 6.78MHz |
coupling range | 0.4 to 0.7 | 0.6 yo 0.8 | 0.1 to 0.5 |
Quality factor | 6 to 10 | 6 to 10 | 40 to 100 |
cost | Medium | High | Small |
Thickness | 0.3 to 1.0 mm | 0.8 to 1.3 mm | 0.2 to 0.5 mm |
Heating of metal | Medium | Medium | Low |
Form factor flexibility | Medium | Low | Medium to High |
Efficiency | Higher than 70% | Higher than 70% | Approx. 50% |
Qi Wireless charging basics and how it works
For basics of Qi wireless charging and mentions how does Qi wireless charging work. Refer Qi Wireless charging➤
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