Disclosed examples include digital isolator modules, isolation circuitry and low-loss multi-order bandpass filter circuits, including a capacitive coupled galvanic isolation circuit with first and second coupling capacitors individually including a first plate and a second plate, and a bond wire connecting the first plates of the coupling capacitors, a first circuit with a first inductor coupled to form a first resonant tank circuit with a first parasitic capacitor associated with the second plate of the first coupling capacitor, and a second circuit with a second inductor coupled to form a second resonant tank circuit with a second parasitic capacitor associated with the second plate of the second coupling capacitor.

Disclosed examples include digital isolator modules, isolation circuitry and low-loss multi-order bandpass filter circuits, including a capacitive coupled galvanic isolation circuit with first and second coupling capacitors individually including a first plate and a second plate, and a bond wire connecting the first plates of the coupling capacitors, a first circuit with a first inductor coupled to form a first resonant tank circuit with a first parasitic capacitor associated with the second plate of the first coupling capacitor, and a second circuit with a second inductor coupled to form a second resonant tank circuit with a second parasitic capacitor associated with the second plate of the second coupling capacitor.

A coupled resonator filter including a first parallel resonator including a first capacitance connected in parallel with a first inductance. The filter includes a second parallel resonator including a second capacitance connected in parallel with a second inductance and a third parallel resonator including a third capacitance connected in parallel with a third inductance. Magnetic coupling between the first inductance and the second inductance, between the second inductance and the third inductance, and between the first inductance the third inductance occurs in accordance with first, second and third coupling factors, respectively. A frequency response of the coupled resonator filter includes a notch when values of the first coupling factor, the second coupling factor and the third coupling factor satisfy predetermined conditions.

A coupled resonator filter including a first parallel resonator including a first capacitance connected in parallel with a first inductance. The filter includes a second parallel resonator including a second capacitance connected in parallel with a second inductance and a third parallel resonator including a third capacitance connected in parallel with a third inductance. Magnetic coupling between the first inductance and the second inductance, between the second inductance and the third inductance, and between the first inductance the third inductance occurs in accordance with first, second and third coupling factors, respectively. A frequency response of the coupled resonator filter includes a notch when values of the first coupling factor, the second coupling factor and the third coupling factor satisfy predetermined conditions.

A coupled resonator filter including a first parallel resonator including a first capacitance connected in parallel with a first inductance. The filter includes a second parallel resonator including a second capacitance connected in parallel with a second inductance and a third parallel resonator including a third capacitance connected in parallel with a third inductance. Magnetic coupling between the first inductance and the second inductance, between the second inductance and the third inductance, and between the first inductance the third inductance occurs in accordance with first, second and third coupling factors, respectively. A frequency response of the coupled resonator filter includes a notch when values of the first coupling factor, the second coupling factor and the third coupling factor satisfy predetermined conditions.

A circuit comprising: a passive reactive component; and an active circuit, the active circuit arranged to increase the ac voltage difference across the reactive component by changing the current at an input to the reactive component and the current at an output of the reactive component by equal and opposite amounts. By increasing the current on one side of the resonant circuit and decreasing the current on the other side of the resonant circuit, the amount of current flowing through the resonant circuit is increased and thus the ac voltage difference across the inductor of the LC resonant circuit is increased. The Q of an inductor (the ratio of its imaginary to real impedance) is increased. In a filter, the improved Q provides a sharp, high rejection notch and faster pass-band to stop-band roll-off, thus improving the frequency response of the circuit.

An electronic component includes a multilayer body including dielectric layers, a circuit pattern, and band-shaped conductor patterns. The circuit pattern includes a conductor pattern that is disposed inside the multilayer body and defines an inductor. The band-shaped conductor patterns are grounded and cover a portion of a shield surface. An internal surface is located between the circuit pattern and an upper surface. On a shield surface, a non-shielded area is provided which is not covered with any of the band-shaped conductor patterns, and through which magnetic flux generated from the inductor is able to pass.

A filter is disposed on a base board. The filter includes a first portion, a second portion, a ground portion, a first coupling portion and a second coupling portion. The first portion is disposed on a first layer in the base board to input signals. The second portion is disposed on the first layer to output signals. The ground portion is disposed on a second layer in the base board. The first coupling portion is disposed on the first layer. The first coupling portion is electrically coupled to the first portion and the second portion. The first coupling portion is electrically coupled to the ground portion through via holes. The second coupling portion is disposed on the first layer. The second coupling portion is electrically coupled to the first portion and the second portion. The second coupling portion is electrically coupled to the ground portion through the via holes.

A filter is disposed on a base board. The filter includes a first portion, a second portion, a ground portion, a first coupling portion and a second coupling portion. The first portion is disposed on a first layer in the base board to input signals. The second portion is disposed on the first layer to output signals. The ground portion is disposed on a second layer in the base board. The first coupling portion is disposed on the first layer. The first coupling portion is electrically coupled to the first portion and the second portion. The first coupling portion is electrically coupled to the ground portion through via holes. The second coupling portion is disposed on the first layer. The second coupling portion is electrically coupled to the first portion and the second portion. The second coupling portion is electrically coupled to the ground portion through the via holes.

A multilayer filter includes dielectric layers, a first terminal, a second terminal, a first inductor, a second inductor, and first to fifth capacitors. In a stacking direction of the dielectric layers, at least one of a first air-core portion defined by the first inductor and a second air-core portion defined by the second inductor includes, in a region from the first inductor layer to the second inductor layer, a region enabling magnetic flux to pass therethrough without being obstructed by the first to fifth capacitors and the third inductor.