Variable impedance network for an integrated circuit potentiometer
AssigneeWinbond Electronics Corp.
InventorsHagop A. Nazarian, William Tang, Zhan Duan, Chao-Ming Tsai, Lawrence D. Engh
Life of this patent
Estimating the term…
Abstract
An impedance network, which includes at least one end terminal, a wiper terminal, a center impedance element, and a first plurality of impedance elements. The wiper terminal provides a tap position at a selected impedance value of the impedance network, selectable at a specified increment value. The first plurality of impedance elements is configured to reduce resistance variation during switching from one tap position to another tap position. The first plurality of impedance elements is connected in series in a mirrored configuration about the center impedance element.
Claims19
An impedance network, comprising:
- at least one end terminal;
- a wiper terminal providing a tap position at a selected impedance value of the impedance network, selectable at a specified increment value, said wiper terminal selectable as an end terminal;
- a center impedance element;
- a first plurality of impedance elements configured to provide a range of impedance values with less number of wiper switching elements than for an impedance network with impedance elements having a uniformly selected increment value, the first plurality of impedance elements connected in series in a mirrored configuration about the center impedance element, wherein said first plurality of impedance elements includes a plurality of connection nodes which enables said first plurality of impedance elements to be connected in series, said first plurality of impedance elements includes a first plurality of wiper switching elements to selectively couple said plurality of connection nodes to the wiper terminal, said first plurality of wiper switching elements includes a plurality of transistors, and on/off states of said plurality of transistors are in a mirrored configuration around the center impedance element.
An impedance network, comprising:
- at least one end terminal;
- a wiper terminal providing a tap position at a selected impedance value of the impedance network, selectable at a specified increment value, said wiper terminal selectable as an end terminal;
- a center impedance element;
- and a first plurality of impedance elements configured to provide a range of impedance values with less number of wiper switching elements than for an impedance network with impedance elements having a uniformly selected increment value, the first plurality of impedance elements connected in series in a mirrored configuration about the center impedance element, wherein each impedance element of said first plurality of impedance elements includes a second plurality of impedance elements selectively connectable in parallel.
A resistance network having end terminals and a wiper terminal, comprising:
- a first set of switching elements;
- a first plurality of resistors selectively connectable in parallel with said first set of switching elements to form an equivalent resistive element where values of said first plurality of resistors are equal;
- a center resistor;
- a second plurality of resistors connected in series in a mirrored configuration about the center impedance element, each resistor of said second plurality of resistors including said equivalent resistive element, resistance values of different equivalent resistive elements in said second plurality of resistors is in a binary configuration with two middle equivalent resistive elements having an equal value with the value of the center resistor;
- and
- a second set of switching elements to couple nodes of said second plurality of resistors to the wiper terminal.
A method for configuring an impedance network, comprising:
- first configuring a first plurality of resistors selectively connectable in parallel;
- connecting a second plurality of resistive elements in series, where each resistive element includes equivalent resistance formed by the first plurality of resistors;
- providing a center resistor;
- second configuring said second plurality of resistive elements into a mirrored configuration with respect to the center resistor;
- and
- selectively connecting nodes of said second plurality of resistive elements to a wiper terminal of the impedance network.
Dependencies are inferred from the claim text.