Systems and methods for driving a control gate with a select gate signal in a split-gate nonvolatile memory cell
View Patent ↗A nonvolatile memory includes a memory array having a plurality of memory cells, a select gate driver configured to provide a select gate voltage to a select gate of a first memory cell of the plurality of memory cells, and a control gate driver configured to use the select gate voltage to provide a control gate voltage to a control gate of a second memory cell of the plurality of memory cells.
1. A nonvolatile memory comprising:
a memory array having a plurality of memory cells;
a select gate driver configured to provide a select gate voltage to a select gate of a first memory cell of the plurality of memory cells; and
a control gate driver configured to use the select gate voltage to provide a control gate voltage to a control gate of a second memory cell of the plurality of memory cells.
2. The nonvolatile memory of claim 1 , wherein the control gate driver is configured to level shift the select gate voltage provided by the select gate driver and use the level shifted select gate voltage to provide the control gate voltage.
3. The nonvolatile memory of claim 1 , wherein the first memory cell and the second memory cell are a same memory cell.
4. The nonvolatile memory of claim 1 , wherein the first memory cell and the second memory cell are located in different rows of the memory array.
5. The nonvolatile memory of claim 1 , wherein the first memory cell and the second memory cell are located in different columns of the memory array.
6. The nonvolatile memory of claim 1 , wherein the control gate driver is configured to provide the control gate voltage at an output node of the control gate driver and comprises:
a first transistor of a first conductivity type having a first current electrode coupled to a first voltage supply node, a control electrode, and a second current electrode coupled to the output node; and
a second transistor of a second conductivity type having a first current electrode coupled to the control electrode of the first transistor, a control electrode coupled to the select gate, and a second current electrode coupled to a second voltage supply node.
7. The nonvolatile memory of claim 6 , further comprising:
a resistive element coupled between the first current electrode and the control electrode of the first transistor; and
a third transistor of the second conductivity type having a first current electrode coupled to the output node, a control electrode coupled to the first current electrode of the second transistor, and a second control electrode coupled to a third voltage supply node.
8. The nonvolatile memory of claim 7 , wherein the resistive element comprises:
a fourth transistor of the first conductivity type having a first current electrode coupled to the first voltage supply node, a second current electrode coupled to the control electrode of the first transistor, and a control electrode coupled to receive a bias voltage.
9. The nonvolatile memory of claim 7 , further comprising:
a first voltage supply switch configured to select a first voltage level provided by the first voltage supply node;
a second voltage supply switch configured to select a second voltage level provided by the second voltage supply node; and
a third voltage supply switch configured to select a third voltage level provided by the third voltage supply node.
10. The nonvolatile memory of claim 6 , further comprising,
a first voltage supply switch configured to select a first voltage level provided by the first voltage supply node; and
a second voltage supply switch configured to select a second voltage level provided by the second voltage supply node.
11. The nonvolatile memory of claim 1 , wherein the select gate driver is configured to provide a corresponding select gate voltage to each select gate of a first plurality of memory cells, and wherein the control gate driver is configured to use the corresponding select gate voltages to provide the control gate voltage.
12. The nonvolatile memory of claim 1 , wherein a highest absolute voltage level of the select gate voltage is less than a highest absolute voltage level of the control gate voltage.
13. A nonvolatile memory comprising:
a memory array;
a select gate driver coupled to a select gate of a first memory cell of the memory array;
a control gate driver coupled to a control gate of a second memory cell, wherein the control gate driver comprises:
a first transistor of a first conductivity type having a first current electrode coupled to a first voltage supply node, a control electrode, and a second current electrode coupled to a driver output node configured to drive a control gate voltage to the control gate of the second memory cell;
a second transistor of a second conductivity type having a first current electrode coupled to the driver output node, a control electrode coupled to the control electrode of the first transistor, and a second current electrode coupled to a second voltage supply node;
a resistive element coupled between the first current electrode and the control electrode of the first transistor; and
a third transistor of the second conductivity type having a first current electrode coupled to the driver output node, a control electrode coupled to the first current electrode of the second transistor, and a second control electrode coupled to a third voltage supply node.
14. The nonvolatile memory of claim 12 , wherein the first memory cell and the second memory cell are a same memory cell.
15. The nonvolatile memory of claim 12 , wherein the resistive element comprises:
a fourth transistor of the first conductivity type having a first current electrode coupled to the first voltage supply node, a second current electrode coupled to the control electrode of the first transistor, and a control electrode coupled to receive a bias voltage.
16. The nonvolatile memory of claim 12 , further comprising:
a first voltage supply switch configured to select a first voltage level provided by the first voltage supply node;
a second voltage supply switch configured to select a second voltage level provided by the second voltage supply node; and
a third voltage supply switch configured to select a third voltage level provided by the third voltage supply node.
17. The nonvolatile memory of claim 16 , further comprising:
mode select logic coupled to provide a mode select signal to the first and second voltage supply, wherein the first voltage supply switch is configured to select the first voltage level from a first plurality of voltage levels based on the mode select signal and the second voltage supply switch is configured to select the second voltage level from a second plurality of voltage levels based on the mode select signal.
18. In a nonvolatile memory, a method comprising:
providing a select gate voltage to a select gate of a first memory cell in the nonvolatile memory;
using the select gate voltage to provide a control gate voltage to a control gate of a second memory cell in the nonvolatile memory.
19. The method of claim 18 , wherein using the select gate voltage to provide the control gate voltage comprises:
level shifting the select gate voltage; and
providing the level shifted select gate voltage as the control gate voltage.
20. The method of claim 18 , further comprising:
providing a corresponding select gate voltage to each select gate of a first plurality of memory cells in the nonvolatile memory;
performing an ORing operation on the corresponding select gate voltages, wherein using the select gate voltage to provide the control gate voltage to the control gate of the second memory cell comprises using a result of the ORing operation to provide the control gate voltage.