公开(公告)号：US20220263486A1

公开(公告)日：2022-08-18

申请号：US17670311

申请日：2022-02-11

申请人： Schaffner EMV AG

发明人： Alessandro AMADUCCI ,  Enrico MAZZOLA

IPC分类号： H03H7/06

摘要： Electromagnetic interference filter for suppressing interferences in DC network, the network comprising a source device powering a load device via a bus connectable to the source device at an input side and to the load device at an output side.
The EMI filter being connected to the bus and comprising an active filter circuit having an active filter bandwidth and being configured to sense a noise component superimposed in the bus and inject a cancelling noise in the bus to suppress said noise component. The EMI filter further comprises a passive circuit including a source circuit connected to the bus at the input side and a passive load circuit to the bus connected at the output side, the passive circuit being configured to provide, at least at a cutoff frequency of the active filter bandwidth, a source impedance at the input side that differs from a load impedance at the output side by a factor of at least two.

公开(公告)号：US20220337226A1

公开(公告)日：2022-10-20

申请号：US17720879

申请日：2022-04-14

申请人： Schaffner EMV AG

发明人： Alessandro AMADUCCI ,  Enrico MAZZOLA

IPC分类号： H03H11/04 ,  H03F3/19 ,  B60R16/02

摘要： A high-frequency amplifier for an active EMI filter with a symmetric class B emitter-follower output stage driven by a driver stage, with a sense output resistor. Both terminals of the sense resistor are brought to the noninverting, respecting inverting input of the driver stage through two dividers of the same ratio, in a global voltage feedback loop. The amplifier is configured to provide a high output impedance at 10 kHz and up to 100 MHz, a peak-to-peak output current of 2-10 ampere and a low quiescent current of less than 400 mA. The invention includes EMI filters with such a high-frequency current source, for example in the current-sense current-inject feedback configuration.