Abstract: The present invention discloses an EMI suppression device, comprising: a first transformer including a first circuit-end central tap to receive a first circuit signal from two first circuit-end signal taps, and a first cable-end central tap to receive a first cable signal from two first cable-end signal taps; a second transformer including a second circuit-end central tap to receive a second circuit signal from two second circuit-end signal taps, and a second cable-end central tap to receive a second cable signal from two second cable-end signal taps; a first circuit-end inductor coupled between the first circuit-end central tap and a system ground to reduce the common mode noise of the first circuit signal; and a second circuit-end inductor coupled between the second circuit-end central tap and the system ground to reduce the common mode noise of the second circuit signal. Said first and second circuit-end inductors operate separately.

Abstract: The present invention discloses an EMI suppression device, comprising: a first transformer including a first circuit-end central tap to receive a first circuit signal from two first circuit-end signal taps, and a first cable-end central tap to receive a first cable signal from two first cable-end signal taps; a second transformer including a second circuit-end central tap to receive a second circuit signal from two second circuit-end signal taps, and a second cable-end central tap to receive a second cable signal from two second cable-end signal taps; a first circuit-end inductor coupled between the first circuit-end central tap and a system ground to reduce the common mode noise of the first circuit signal; and a second circuit-end inductor coupled between the second circuit-end central tap and the system ground to reduce the common mode noise of the second circuit signal. Said first and second circuit-end inductors operate separately.

Abstract: A noise filtering circuit for suppressing electromagnetic interference (EMI) is provided. The noise filtering circuit filters out high multiplied-frequency noise of a digital signal being transmitted and includes a reference voltage structure formed from conductors, a signal transmitting structure formed from a transmission conductor, a ground layer, and a ground structure electrically connected to the reference voltage structure and the ground layer. The ground structure is configured to form an inductor-capacitor oscillating structure in coordination with the electric-magnetical coupling between the reference voltage structure and the signal transmitting structure as well as the inductance of the ground structure, so that a digital signal is filtered out at a specific frequency and the passband of the digital signal can be transmitted.

Abstract: A common mode noise suppression circuit applicable to differential signal transmission performs common mode noise suppression with respect to differential signals transmitted by a transmission line. An inductance-capacitance resonant structure is formed based on electromagnetic coupling combining a ground structure to suppress common mode noise of differential mode signals at broadband meanwhile keeping low loss of the differential mode signals at broadband via differential transmission lines. By this, the common mode noise suppression circuit performs broadband suppression with related to the common mode noise within a frequency scope of several GHz without affecting the differential mode signals and improves manufacturing process miniaturization to decrease cost.

Abstract: A noise filtering circuit for suppressing electromagnetic interference (EMI) is provided. The noise filtering circuit filters out high multiplied-frequency noise of a digital signal being transmitted and includes a reference voltage structure formed from conductors, a signal transmitting structure formed from a transmission conductor, a ground layer, and a ground structure electrically connected to the reference voltage structure and the ground layer. The ground structure is configured to form an inductor-capacitor oscillating structure in coordination with the electric-magnetical coupling between the reference voltage structure and the signal transmitting structure as well as the inductance of the ground structure, so that a digital signal is filtered out at a specific frequency and the passband of the digital signal can be transmitted.

Abstract: A common mode noise suppression circuit applicable to differential signal transmission performs common mode noise suppression with respect to differential signals transmitted by a transmission line. An inductance-capacitance resonant structure is formed based on electromagnetic coupling combining a ground structure to suppress common mode noise of differential mode signals at broadband meanwhile keeping low loss of the differential mode signals at broadband via differential transmission lines. By this, the common mode noise suppression circuit performs broadband suppression with related to the common mode noise within frequency scope of several GHzs without affecting the differential mode signals and improves manufacturing process miniaturization to decrease cost.