Patent ID: 6922046

Claim:
An impedance network, comprising: first and second impedance network terminals; a wiper terminal; first, second, third, fourth and fifth pluralities of impedance elements, each plurality of impedance elements being connected in series, the first, third and fifth pluralities of impedance elements being equal in number, the second and fourth pluralities of impedance elements being equal in number, the second, third and fourth pluralities of series connected impedance elements being connected in series in the order of second, third and fourth pluralities of impedance elements, a first end of the series connection of the first plurality of impedance elements being connected to the first impedance network terminal and a first end of the series connection of the fifth plurality of impedance elements being connected to the second impedance network terminal, each connection to and between impedance elements forming nodes; a first plurality of switching elements selectively coupling nodes in the third plurality of impedance elements to the wiper terminal; a second plurality of switching elements selectively coupling nodes in the first and fifth pluralities of impedance elements to the wiper terminal; a third plurality of switching elements selectively coupling nodes in the second and fourth pluralities of impedance elements to second ends of the series connections of the first and fifth impedance elements.