High-resolution, high-precision solid-state potentiometer

A potentiometer network comprising:

• a first main terminal and a second main terminal;
• a first variable resistance network comprising a first terminal, a second terminal, and a first variable resistance value (R1) which varies between zero ohms and a first resistance level (RP), the first terminal of the first variable resistance network being coupled to the first main terminal;
• a second variable resistance network comprising a first terminal, a second terminal, and a second variable resistance value (R2), the first terminal of the second variable resistance network being coupled to the second main terminal;
• a resistor stack comprising a first plurality of resistors coupled in series to one another at a plurality of internal nodes, each internal node coupling two adjacent resistors of the stack, the first resistor in the stack having a terminal coupled to the second terminal of the first variable resistance network, the last resistor in the stack having a terminal coupled to the second terminal of the second variable resistance network, each resistor of said resistor stack having a value substantially equal to a second resistance level (RS);
• and
• a wiper terminal coupled to one of the plurality of internal nodes of the resistor stack, or to one of the second terminals of the variable resistor networks, or to one of the first and second main terminals;
• and
• wherein the first variable resistance network comprises a first resistor, and a first switch which selectively couples the first resistor of the first variable resistance network between the first and second terminals of the first variable resistance network,
• wherein the first switch has a conducting state which couples the first resistor of the first variable resistance network to the first and second terminals of the first variable resistance network, a non-conducting state, and a non-zero conduction resistance (RON) when it is in its conducting state, and
• wherein the first resistor of the first variable resistance network has a non-zero resistance.

A potentiometer network comprising:

• a first main terminal and a second main terminal;
• a first variable resistance network comprising a first terminal, a second terminal, and a first variable resistance value (R1) which varies between zero ohms and a first resistance level (RP), the first terminal of the first variable resistance network being coupled to the first main terminal;
• a second variable resistance network comprising a first terminal, a second terminal, and a second variable resistance value (R2), the first terminal of the second variable resistance network being coupled to the second main terminal;
• a resistor stack comprising a first plurality of resistors coupled in series to one another at a plurality of internal nodes, each internal node coupling two adjacent resistors of the stack, the first resistor in the stack having a terminal coupled to the second terminal of the first variable resistance network, the last resistor in the stack having a terminal coupled to the second terminal of the second variable resistance network, each resistor of said resistor stack having a value substantially equal to a second resistance level (RS);
• and
• a wiper terminal coupled to one of the plurality of internal nodes of the resistor stack, or to one of the second terminals of the variable resistor networks, or to one of the first and second main terminals;
• and
• wherein said first variable resistance network comprises:
• a plurality of discrete resistance values for said first variable resistance value,
• a sense terminal, and
• a plurality of selectable parallel current branches having a first current branch and one or more remaining current branches, the first current branch being coupled between the first and second terminals of said first variable resistance network, each remaining current branch being coupled between the first and second terminals of said first variable resistance network, the first current branch comprising a switch, each remaining current branch comprising a resistor and a double-pole single-throw switch having a first pole and a second pole, each remaining current branch having its resistor coupled in series with the first pole of its switch to form a series combination that is coupled between the first and second terminals of the first variable resistance network, each remaining branch further having its resistor coupled in series with the second pole of its switch to form a series combination that is coupled between the first terminal and the sense terminal of the first variable resistance network;
• and
• wherein said wiper terminal is selectively coupled to the sense terminal.

A potentiometer network comprising:

• a first main terminal and a second main terminal;
• a first variable resistance network comprising a first terminal, a second terminal, and a first variable resistance value (R1) which varies between zero ohms and a first resistance level (RP), the first terminal of the first variable resistance network being coupled to the first main terminal;
• a second variable resistance network comprising a first terminal, a second terminal, and a second variable resistance value (R2), the first terminal of the second variable resistance network being coupled to the second main terminal;
• a resistor stack comprising a first plurality of resistors coupled in series to one another at a plurality of internal nodes, each internal node coupling two adjacent resistors of the stack, the first resistor in the stack having a terminal coupled to the second terminal of the first variable resistance network, the last resistor in the stack having a terminal coupled to the second terminal of the second variable resistance network, each resistor of said resistor stack having a value substantially equal to a second resistance level (RS);
• a wiper terminal coupled to one of the plurality of internal nodes of the resistor stack, or to one of the second terminals of the variable resistor networks, or to one of the first and second main terminals;
• and
• wherein said first variable resistance network comprises a plurality of discrete resistance values for said first variable resistance value,
• a sense terminal,
• a second plurality of resistors equal in number to said plurality of discrete resistance values minus one, said second plurality of resistors being coupled in series at a set of intermediate nodes to form a line of series-connected resistors, one of said second plurality of resistors being a first resistor in the line and another one of said second plurality of resistors being a last resistor in the line, the first and last resistors of the second plurality of resistors each having a free terminal which is not connected to an intermediate node, the free terminal of the first resistor of the second plurality of resistors being coupled to the first terminal of said variable resistance network,
• a first switch coupled between the first and second terminals of the first variable resistance network, and
• a plurality of double-pole single-throw switches equal in number to said second plurality of resistors, a first one of the double-pole single-throw switches having its first pole coupled between the free terminal of the last resistor in the line and the second terminal of the first variable resistance network and having its second pole coupled between the free terminal of the last resistor in the line and the sense terminal, each other double-pole single-throw switch having its first pole coupled between a respective intermediate node and the second terminal of the first variable resistance network and having its second pole coupled between the same respective intermediate node and the sense terminal.