초록 ▼

A novel electromagnetic interference (EMI) filter is designed to attenuate one or more specific frequencies in order to provide electromagnetic compatibility of an electronic device while in the presence of an electromagnetic emitter operating at the same or similar frequencies. The EMI filter of th

A novel electromagnetic interference (EMI) filter is designed to attenuate one or more specific frequencies in order to provide electromagnetic compatibility of an electronic device while in the presence of an electromagnetic emitter operating at the same or similar frequencies. The EMI filter of the present invention combines an EMI low pass filter with one or more "notch" EMI filters tuned to the specific frequencies of interest. When combined in this fashion, the notch EMI filter can effectively attenuate the electromagnetic field of a powerful low frequency emitter which is outside the effective attenuation frequency range of the low pass filter, which is itself effective at filtering a broad range of higher frequencies. In a preferred embodiment, the notch EMI filter capacitive element is integrated in a co-planar relationship with a ceramic feedthrough filter capacitor assembly. This combined notch and low pass filter arrangement is particularly effective in an implantable medical device such as a cardiac pacemaker or implantable cardioverter defibrillator (ICD) against passage of external interference signals, such as those caused by both digital cellular phones and electronic article surveillance systems operating at low frequencies.

대표청구항 ▼

1. An electromagnetic interference (EMI) filter, comprising:a broadband electromagnetic interference (EMI) filter associated with one or more leads of an electronic device and capable of attenuating a range of frequencies; and an inductor-capacitor (L-C) series resonant notch electromagnetic interfe

1. An electromagnetic interference (EMI) filter, comprising:a broadband electromagnetic interference (EMI) filter associated with one or more leads of an electronic device and capable of attenuating a range of frequencies; and an inductor-capacitor (L-C) series resonant notch electromagnetic interference (EMI) filter associated with the leads of the electronic device and capable of attenuating a specific frequency outside the attenuation range of the broadband EMI filter; wherein the broadband EMI filter comprises a capactive low pass filter in a feedthrough filter capacitor, comprising: a casing of dielectric material through which the leads of the electronic device extend; a first set of electrode plates disposed within the casing in conductive relation with the leads of the electronic device, a second set of electrode plates disposed within the casing in non-conductive relation with the leads of the electronic device and in an alternating stack with the first set of electrode plates, and a first conductive termination surface conductively coupled to the second set of electrode plates, wherein the first and second sets of electrode plates form the broadband EMI filter; and a third set of electrode plates disposed within the casing in conductive relation with the leads of the electronic device, a fourth set of electrode plates disposed within the casing in non-conductive relation with the leads of the electronic device and in an alternating stack with the third set of electrode plates, and a second conductive termination surface conductively coupled to the fourth set of electrode plates, wherein the third and fourth sets of electrode plates form the capacitive element of the notch EMI filter.