POWER ELECTROMAGNETIC INTERFERENCE SUPPRESSION FILTER

摘要

A power EMI suppression filter is connected to a power feeding line of a main functional IC and other loads. The main functional IC driven by a power source supplied by the power feeding line generates an output voltage and current which are individually involved with an output voltage interference and output current interference, and a phase difference exits there-in-between. A reference providing circuit generates a first reference signal according to the output voltage interference and/or the output current interference. A primary filtering circuit calculates eigenvalues of the output voltage interference and/or the output current interference according to the first reference signal to generate a second reference signal. A secondary filtering circuit calculates eigenvalues again based on the second signal so the phase difference and amplitudes of the interferences are zero. Thus, an output voltage and current signal the load receives are DC signal without interferences.

主权项

1. A power electromagnetic interference suppression filter, which is electrically connected to a power feeding line of a main functional IC and a load, wherein said main functional IC generates an output voltage and an output current after said main functional IC is driven by a power source supplied by said power feeding line; said output voltage is involved with an output voltage interference; said output current is involved with an output current interference; and a phase difference exits between said output voltage interference and said output current interference owing to harmonics interferences generated at said power source, said power electromagnetic interference suppression filter comprising:
a reference providing circuit, electrically coupled to said main functional IC and outputting a first reference signal according to said output voltage interference and/or said output current interference; a primary filtering circuit, connected to said reference providing circuit in parallel for receiving said first reference signal, wherein said primary filtering circuit calculates eigenvalues of said output voltage interference and/or said output current interference according to said first reference signal and outputs a second reference signal; and a secondary filtering circuit, connected to said primary filtering circuit for receiving said second reference signal, wherein said secondary filtering circuit accordingly calculates eigenvalues of said output voltage interference and/or said output current interference according to said second reference signal such that said phase difference is adjusted to zero, amplitudes of said output voltage interference and said output current interference are adjusted to zero as well, and an output voltage signal and an output current signal that said load receives are merely direct current (DC) signal without any interferences or harmonics involved.