Cell array with mismatch reduction
View Patent ↗A cell array has a plurality of cell elements integrated in a wafer in a bidimensional cell matrix, wherein each integrated cell element comprises a mismatch between its actual physical property and a nominal property value. The mismatch of each cell element is a function of the distance of the respective cell element to a center of the cell array having a bidimensional mismatch distribution which is circular symmetric. The cell elements are connected in series in a wiring pattern along the circular symmetric mismatch distribution of the cell array to reduce an accumulated mismatch.
1. A cell array having a plurality of cell elements integrated on a wafer in a bidimensional cell matrix, at least one integrated cell element exhibiting a mismatch between its actual physical property and a nominal property value, the mismatch of the at least one cell element being a function of the distance of the respective cell element to a center of the cell array having a bidimensional mismatch distribution, the plurality of cell elements arranged in rows and columns; wherein the cell elements are connected in series in a wiring pattern in which,
for a plurality of rows of cell elements, each row of cell elements includes more than two series connections to cell elements of one or more other rows, and
for a plurality of columns of cell elements, each column of cell elements includes more than two series connections to cell elements of one or more other columns; and
wherein the cell matrix comprises a first number (N) of cell element rows and a second number (M) of cell element columns, and wherein the first number (N) of cell element rows is equal to the second number (M) of cell element columns.
2. A cell array having a plurality of cell elements integrated on a wafer in a bidimensional cell matrix, at least one integrated cell element exhibiting a mismatch between its actual physical property and a nominal property value, the mismatch of the at least one cell element being a function of the distance of the respective cell element to a center of the cell array having a bidimensional mismatch distribution, the plurality of cell elements arranged in rows and columns; wherein the cell elements are connected in series in a wiring pattern in which,
for a plurality of rows of cell elements, each row of cell elements includes more than two series connections to cell elements of one or more other rows, and
for a plurality of columns of cell elements, each column of cell elements includes more than two series connections to cell elements of one or more other columns; and
wherein the cell array is surrounded by dummy cell elements.
3. A cell array having a plurality of cell elements integrated on a wafer in a bidimensional cell matrix, at least one integrated cell element exhibiting a mismatch between its actual physical property and a nominal property value, the mismatch of the at least one cell element being a function of the distance of the respective cell element to a center of the cell array having a bidimensional mismatch distribution, the plurality of cell elements arranged in rows and columns; wherein the cell elements are connected in series in a wiring pattern in which,
for a plurality of rows of cell elements, each row of cell elements includes more than two series connections to cell elements of one or more other rows, and
for a plurality of columns of cell elements, each column of cell elements includes more than two series connections to cell elements of one or more other columns; and
wherein the wiring pattern includes at least three series connected cell elements that are successively displaced from each other by one row and one column.
4. The cell array according to claim 3 , wherein the wiring pattern includes at least a portion that connects cells in a meandrous form.
5. The cell array according to claim 3 , wherein the wiring pattern includes at least a portion that connects cells in a helical form.
6. The cell array according to claim 3 , wherein each cell element of the integrated cell array is bridgeable by a corresponding switch.
7. The cell array according to claim 6 , wherein the corresponding switch is provided within the integrated cell array.
8. The cell array according to claim 6 , wherein the corresponding switch is provided outside the integrated cell array.
9. A cell array having a plurality of cell elements integrated on a wafer in a bidimensional cell matrix, at least one integrated cell element exhibiting a mismatch between its actual physical property and a nominal property value, the mismatch of the at least one cell element being a function of the distance of the respective cell element to a center of the cell array having a bidimensional mismatch distribution, the plurality of cell elements arranged in rows and columns, wherein the cell elements are connected in series in a wiring pattern in which,
for a plurality of rows of cell elements, each row of cell elements includes more than two series connections to cell elements of one or more other rows, and
for a plurality of columns of cell elements, each column of cell elements includes more than two series connections to cell elements of one or more other columns; and
wherein the cell elements comprise capacitors.
10. A cell array having a plurality of cell elements integrated on a wafer in a bidimensional cell matrix, at least one integrated cell element exhibiting a mismatch between its actual physical property and a nominal property value, the mismatch of the at least one cell element being a function of the distance of the respective cell element to a center of the cell array having a bidimensional mismatch distribution, the plurality of cell elements arranged in rows and columns; wherein the cell elements are connected in series in a wiring pattern in which,
for a plurality of rows of cell elements, each row of cell elements includes more than two series connections to cell elements of one or more other rows, and
for a plurality of columns of cell elements, each column of cell elements includes more than two series connections to cell elements of one or more other columns; and
wherein the cell elements comprise varactors.
11. A cell array having a plurality of cell elements integrated on a wafer in a bidimensional cell matrix, at least one integrated cell element exhibiting a mismatch between its actual physical property and a nominal property value, the mismatch of the at least one cell element being a function of the distance of the respective cell element to a center of the cell array having a bidimensional mismatch distribution, the plurality of cell elements arranged in rows and columns; wherein the cell elements are connected in series in a wiring pattern in which,
for a plurality of rows of cell elements, each row of cell elements includes more than two series connections to cell elements of one or more other rows, and
for a plurality of columns of cell elements, each column of cell elements includes more than two series connections to cell elements of one or more other columns; and
wherein the cell elements comprise resistors.
12. A cell array having a plurality of cell elements integrated on a wafer in a bidimensional cell matrix, at least one integrated cell element exhibiting a mismatch between its actual physical property and a nominal property value, the mismatch of the at least one cell element being a function of the distance of the respective cell element to a center of the cell array having a bidimensional mismatch distribution, the plurality of cell elements arranged in rows and columns; wherein the cell elements are connected in series in a wiring, pattern in which,
for a plurality of rows of cell elements, each row of cell elements includes more than two series connections to cell elements of one or more other rows, and
for a plurality of columns of cell elements, each column of cell elements includes more than two series connections to cell elements of one or more other columns; and
wherein the cell elements comprise current sources.
13. A cell array having a plurality of cell elements integrated on a wafer in a bidimensional cell matrix, at least one integrated cell element exhibiting a mismatch between its actual physical property and a nominal property value, the mismatch of the at least one cell element being a function of the distance of the respective cell element to a center of the cell array having a bidimensional mismatch distribution, the plurality of cell elements arranged in rows and columns; wherein the cell elements are connected in series in a wiring pattern in which,
for a plurality of rows of cell elements, each row of cell elements includes more than two series connections to cell elements of one or more other rows, and
for a plurality of columns of cell elements, each column of cell elements includes more than two series connections to cell elements of one or more other columns; and
wherein the cell elements comprise transistors.
14. A cell array having a plurality of cell elements integrated on a wafer in a bidimensional cell matrix, at least one integrated cell element exhibiting a mismatch between its actual physical property and a nominal property value, the mismatch of the at least one cell element being a function of the distance of the respective cell element to a center of the cell array having a bidimensional mismatch distribution, the plurality of cell elements arranged in rows and columns; wherein the cell elements are connected in series in a wiring pattern in which,
for a plurality of rows of cell elements, each row of cell elements includes more than two series connections to cell elements of one or more other rows, and
for a plurality of columns of cell elements, each column of cell elements includes more than two series connections to cell elements of one or more other columns; and
wherein the cell elements comprise diodes.
15. A digital to analog converter comprising:
a cell array having a plurality of cell elements integrated on a wafer in a bidimensional cell matrix, at least one integrated cell element exhibiting a mismatch between its actual physical property and a nominal property value, the mismatch of the at least one cell element being a function of the distance of the respective cell element to a center of the cell array having a bidimensional mismatch distribution, the plurality of cell elements connected in series in a wiring pattern; and
a number of dummy cells extending around a perimeter of the cell array, wherein each of the dummy cell has nominal property values substantially equivalent to one of the cell elements in the cell array.
16. The analog to digital converter according to claim 15 wherein the plurality of cell elements form a plurality of rows and a plurality of columns, and wherein:
at least one dummy cell is disposed adjacent to first and second ends of each row; and
at least one dummy cell is disposed adjacent to first and second ends of each column.
17. The digital-to-analog converter according to claim 16 wherein the plurality of cell elements form a plurality of rows and a plurality of columns, and wherein:
at least one row of cell elements includes more than two series connections to cell elements of one or more other rows; and
at least one column of cell elements includes more than two series connections to cell elements of one or more other columns.