I/O cell ESD system
An integrated circuit including an ESD network including a portion located in ESD subareas of a plurality of I/O cells where the ESD subareas are arranged in a row traversing the plurality of I/O cells. The ESD network includes ESD clamp cells and ESD trigger circuit cells wherein a portion of the network is located in the row. In some examples, the row includes an ESD trigger circuit cell with a portion in one subarea of one ESD subarea of one I/O cell and a second portion in a second ESD subarea of another I/O cell. Also described herein is a method for producing an integrated circuit layout with an ESD network.
1. A method of making an integrated circuit, the method comprising:
arranging a bank of I/O cells in an integrated circuit layout, the bank including a plurality of I/O cells, wherein each I/O cell of the plurality of I/O cells in the bank includes a designated ESD subarea, wherein the designated ESD subareas are aligned in a continuous row traversing adjacent boundaries of the plurality of I/O cells in a layout;
after the arranging, placing in the layout a plurality of ESD clamp cells and at least one ESD trigger circuit cell for an ESD network in the row;
manufacturing the integrated circuit as per the layout.
2. The method of claim 1 wherein after the manufacturing, the integrated circuit includes an ESD trigger circuit cell of the at least one ESD trigger circuit cell, the ESD trigger circuit cell including a first portion in an ESD subarea of a first I/O cell of the plurality of I/O cells and a second portion in an ESD subarea of a second I/O cell of the plurality of I/O cells.
3. The method of claim 1 wherein after the manufacturing, the integrated circuit includes an ESD clamp cell of the plurality of ESD clamp cells including a first portion in an ESD subarea of a first I/O cell of the plurality and a second portion in an ESD subarea of a second I/O cell of the plurality of I/O cells.
4. The method of claim 3 wherein after the manufacturing, the clamp cell includes a third portion in an ESD subarea of a third I/O cell of the plurality of I/O cells.
5. The method of claim 1 wherein the placing includes placing in the layout a set of ESD clamp cells in the row followed by replacing at least one ESD clamp cell of the set with the at least one ESD trigger circuit cell.
6. The method of claim 1 wherein the placing includes placing the plurality of ESD clamp cells and the at least one ESD trigger circuit cell in the row such that the ESD network meets predefined ESD I/O integration rules.
7. The method of claim 1 wherein each ESD subarea of the I/O cells of the plurality of I/O cells is of a same size in a second direction, wherein the row traverses the plurality of I/O cells in a first direction that is orthogonal to the second direction.
8. The method of claim 1 wherein a first I/O cell of the plurality of I/O cells in the layout has a first size in a first direction and a second I/O cell of the plurality of I/O cells has a second size different from the first size in the first direction, wherein the row traverses the plurality of I/O cells in the first direction.
9. The method of claim 1 wherein after the manufacturing, the plurality of ESD clamp cells includes a first subset of at least one ESD clamp cell having a first size in a first direction and a second subset of at least one ESD clamp cell having a second size in the first direction different from the first size, wherein the row traverses the plurality of I/O cells in the first direction.
10. The method of claim 1 wherein the placing includes placing a first subset of the plurality of ESD clamp cells at a first designated area of each ESD subarea of a first subset of I/O cells of the plurality of I/O cells, wherein after the placing the first subset, the placing includes placing a second subset of the plurality of ESD clamp cells at locations of the row other than the first designated area of each ESD subarea of the first subset of I/O cells.
11. The method of claim 10 wherein after the placing the first subset, the placing includes placing the at least one ESD trigger circuit cell at locations of the row other than the first designated area of each ESD subarea of the first subset of I/O cells.
12. An integrated circuit comprising:
a plurality of I/O cells located in a bank of I/O cells, each I/O cell of the plurality of I/O cells occupying an area of the bank;
an ESD network circuit portion located within the bank, wherein the ESD network circuit portion includes a plurality of ESD clamp cells and at least one ESD trigger circuit cell;
wherein each I/O cell of the plurality includes an ESD subarea, wherein each ESD subarea of the plurality of I/O cells includes a portion of the ESD network portion, wherein the ESD subareas are aligned in a continuous row traversing the plurality of I/O cells, with one or more independent ESD circuits straddling adjacent I/O cells of the plurality of I/O cells;
wherein an ESD trigger circuit cell of the at least one ESD trigger circuit cells includes a first portion located in an ESD subarea of a first I/O cell of the plurality of I/O cells and a second portion located in an ESD subarea of a second I/O cell of the plurality of I/O cells.
13. The integrated circuit of claim 12 wherein an ESD clamp cell of the plurality of ESD clamp cells includes a first portion located in an ESD subarea of a third I/O cell of the plurality of I/O cells and a second portion located in an ESD subarea of a fourth I/O cell of the plurality of I/O cells adjacent to the third I/O cell.
14. The integrated circuit of claim 13 wherein the ESD clamp cell includes a third portion located in an ESD subarea of a fifth I/O cell of the plurality of I/O cells.
15. The integrated circuit of claim 12 wherein an ESD clamp cell of the plurality of ESD clamp cells includes a first portion located in the ESD subarea of the first I/O cell and a second portion located in an ESD subarea of a third I/O cell of the plurality of I/O cells.
16. The integrated circuit of claim 15 wherein the second I/O cell is located on an opposite side of the first I/O cell from the third I/O cell.
17. The integrated circuit of claim 12 wherein each subarea of the I/O cells of the plurality of I/O is of a same size in a second direction, wherein the row traverses the plurality of I/O cells in a first direction that is orthogonal to the second direction.
18. The integrated circuit of claim 12 wherein the first I/O cell has a size in a first direction and the second I/O cell has a second size different from the first size in the first direction, wherein the row traverses the plurality of I/O cells in the first direction.
19. The integrated circuit of claim 12 wherein the plurality of ESD clamp cells includes a first subset of at least one ESD clamp cell having a first size in a first direction and a second subset of at least one ESD clamp cell having a second size in the first direction different from the first size, wherein the row traverses the plurality of I/O cells in the first direction.
20. The integrated circuit of claim 12 includes a decoupling capacitor in the row.