Abstract: A 7th order splitter for replacing the known 9th order splitter of an ISDN/POTS telecommunication system and reducing thereby the space occupied on the board as well as the cost. The 7th order splitter comprising, between line terminals (Line+, Line?) and POTS/ISDN terminals, the cascade connection of a LC filter cell (L21a, L12b, C21) and several elliptical filter cells (L22a, L22b, C22, C24, C25; L23a, L23b, C23, C26, C27). One or more of these filter cells is associated with a damped series resonance circuit comprising a capacitor (C21; C22; C23) series coupled with an RL circuit (R21, L24; R22, L25; R23, L26) between two winding (L21a, L21b; L22a, L22b; L23a, L23b) of a symmetrical coil of the associated filter cell. Each RL circuit is constituted by the parallel coupling of a resistor (R21; R22; R23) and a coil (L24; L25; L26).

Abstract: A 7th order splitter for replacing the known 9th order splitter of an ISDN/POTS telecommunication system and reducing thereby the space occupied on the board as well as the cost. The 7th order splitter comprising, between line terminals (Line+, Line?) and POTS/ISDN terminals, the cascade connection of a LC filter cell (L21a, L12b, C21) and several elliptical filter cells (L22a, L22b, C22, C24, C25; L23a, L23b, C23, C26, C27). One or more of these filter cells is associated with a damped series resonance circuit comprising a capacitor (C21; C22; C23) series coupled with an RL circuit (R21, L24; R22, L25; R23, L26) between two winding (L21a, L21b; L22a, L22b; L23a, L23b) of a symmetrical coil of the associated filter cell. Each RL circuit is constituted by the parallel coupling of a resistor (R21; R22; R23) and a coil (L24; L25; L26).

Abstract: An enhancement circuit for enhancing the value of a coil having a first winding. The enhancement circuit comprises a second winding forming a transformer with the first winding and having a first terminal coupled to the ground and a second terminal coupled to an input of a feedback circuit. The feedback circuit senses the voltage over the coil and comprises a transconductance amplifier that amplifies and converts the sensed voltage into a current injected back in the second winding. In a preferred embodiment, the coil has a pair of windings and is used in a double-ended low-pass filter, as an xDSL splitter for telecommunication applications. The pair of windings is then coupled between telecommunication input terminals and output terminals of the low-pass filter. The improved enhancement circuit comprises a third and a fourth winding both coupled to the first and second windings.