Sense amplifier circuitry and architecture to write data into and/or read from memory cells
View Patent ↗A technique of, and circuitry for sampling, sensing, reading and/or determining the data state of a memory cell of a memory cell array (for example, a memory cell array having a plurality of memory cells which consist of an electrically floating body transistor). In one embodiment, sense amplifier circuitry is relatively compact and pitched to the array of memory cells such that a row of data may be read, sampled and/or sensed during a read operation. In this regard, an entire row of memory cells may be accessed and read during one operation which, relative to at least architecture employing multiplexer circuitry, may minimize, enhance and/or improve read latency and read access time, memory cell disturbance and/or simplify the control of the sense amplifier circuitry and access thereof. The sense amplifier circuitry may include write back circuitry to modify or “re-store” the data read, sampled and/or sensed during a read operation and/or a refresh operation in the context of a DRAM array. The sense amplifier circuitry of this embodiment restores and/or refreshes data in an entire row of volatile and/or destructive read type memory cells in parallel. This architecture may minimize, enhance and/or improve write back and read latency parameters, relative to at least architecture employing multiplexer circuitry. Also, data that has been read, sampled and/or sensed by the sense amplifier circuitry during a read operation may be modified before being written back to one or more of the memory cells of the selected row of the array of memory cells.
1. An integrated circuit device comprising:
a bit line having a plurality of memory cells coupled thereto wherein each memory cell includes an electrically floating body transistor including:
a source region;
a drain region;
a body region disposed between the source region and the drain region,
wherein the body region is electrically floating; and
a gate disposed over the body region; and
wherein each memory cell includes:
a first data state representative of a first charge in the body region of the transistor; and
a second data state representative of a second charge in the body region of the transistor;
a cross-coupled sense amplifier including first and second input nodes, each input node having an intrinsic capacitance, wherein the cross-coupled sense amplifier includes:
a first transistor having first and second regions and a gate, wherein the first region is connected to or forms a part of the first input node, and wherein the first input node is coupled to the bit line to receive a current which is representative of a data state of a selected memory cell, wherein the selected memory cell is one of the plurality of memory cells which are coupled to the bit line; and
a second transistor having first and second regions and a gate, wherein the first region of the second transistor is connected to or forms a part of the second input node, and wherein the second input node receives a reference current; and reference current generation circuitry, coupled to the second input node of the sense amplifier, to generate a current that is representative of the reference current;
write back circuitry, coupled to the first and second input nodes of the cross-coupled sense amplifier, to restore the data state of the selected memory cell or write a different data state into the selected memory cell; and
wherein, in operation, the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes.
2. The integrated circuit device of claim 1 wherein the gate of the first transistor of the sense amplifier is connected to the second input node and the gate of the second transistor of the sense amplifier is connected to the first input node.
3. The integrated circuit device of claim 2 wherein the second region of the first transistor of the sense amplifier is connected to a first reference voltage and the second region of the second transistor of the sense amplifier is connected to the first reference voltage.
4. The integrated circuit device of claim 1 wherein the cross-coupled sense amplifier further includes third and fourth transistors, each having first and second regions and a gate, wherein:
the first regions of the third and fourth transistors are connected end coupled to a second rererence voltage;
the second region of the third transistor is connected to or forms a part of the first input node;
the second region of the fourth transistor is connected to or forms a part of the second input node;
the gate of the third transistor is connected to the second input node; and
the gate of the fourth transistor is connected to the first input node.
5. The integrated circuit device of claim 1 further including a first current mirror circuit coupled between the bit line and the first input node.
6. The integrated circuit device of claim 5 wherein the first current mirror circuit includes an input which is connected to the bit line and an output which is connected to the first input node.
7. The integrated circuit device of claim 5 further including a second current mirror circuit coupled between the reference current generation circuitry and the second input node.
8. The integrated circuit device of claim 7 wherein the second current mirror circuit includes an input which is connected to the reference current generation circuitry and an output which is connected to the second input node.
9. The integrated circuit device of claim 5 wherein the first current mirror circuit, in operation, decouples the bit line capacitance from the first input node.
10. The integrated circuit device of claim 1 wherein the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes provided by:
charging or discharging the intrinsic capacitance of the first input node by the current which is representative of the data state of the selected memory cell; and
charging or discharging the intrinsic capacitance of the second input node by the reference current.
11. The integrated circuit device of claim 1 further including voltage level shifter circuitry, coupled between the write back circuitry and the first and second input nodes of the cross-coupled sense amplifier.
12. An integrated circuit device comprising:
a bit line having a plurality of memory cells coupled thereto wherein each memory cell includes an electrically floating body transistor including:
a source region;
a drain region;
a a body region disposed between the source region and the drain region, wherein the body region is electrically floating; and
a gate disposed over the body region; and
wherein each memory cell includes:
a first data state representative of a first charge in the body region of the transistor; and
a second data state representative of a second charge in the body region of the transistor;
a cross-coupled sense amplifier including first and second input nodes, each input node having an intrinsic capacitance, wherein the cross-coupled sense amplifier further includes:
a first transistor having first and second regions and a gate, wherein the first region is connected to or forms a part of the first input node, and wherein the first input node is coupled to the bit line to receive a current which is representative of a data state of a selected memory cell, wherein the selected memory cell is one of the plurality of memory cells which are coupled to the bit line; and
a second transistor having first and second regions and a gate, wherein the first region of the second transistor is connected to or forms a part of the second input node, and wherein the second input node receives a reference current; and reference current generation circuitry, coupled to the second input node of the sense amplifier, to generate a current that is representative of the reference current;
first current mirror circuit, coupled between the bit line and the cross-couled sense amplifier such that an input is coupled to the bit line and an output is coupled to the first input node, wherein the first current mirror circuit, in operation, decouples the bit line capacitance from the first input node; and
wherein, in operation, the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes.
13. The integrated circuit device of claim 12 wherein:
the gate of the first transistor of the sense amplifier is connected to the second input node and the gate of the second transistor of the sense amplifier is connected to the first input node; and
the second region of the first transistor of the sense amplifier is connected to a first reference voltage and the second region of the second transistor of the sense amplifier is connected to the first reference voltage.
14. The integrated circuit device of claim 13 wherein the cross-coupled sense amplifier further includes third and fourth transistors, each having first and second regions and a gate, wherein:
the first regions of the third and fourth transistors are connected and coupled to a second reference voltage;
the second region of the third transistor is connected to or forms a part of the first input node;
the second region of the fourth transistor is connected to or forms a part of the second input node;
the gate of the third transistor is connected to the second input node; and
the gate of the fourth transistor is connected to the first input node.
15. The integrated circuit device of claim 12 further including a second current mirror circuit coupled between the reference current generation circuitry and the second input node wherein the second current mirror circuit includes an input which is coupled to the reference current generation circuitry and an output which is coupled to the second input node.
16. The integrated circuit device of claim 12 further including write back circuitry, coupled to the first and second input nodes of the cross-coupled sense amplifier, to restore the data state of the selected memory cell or write a different data state into the selected memory cell.
17. The integrated circuit device of claim 16 further including voltage level shifter circuitry, disposed between the write back circuitry and the cross-coupled sense amplifier.
18. The integrated circuit device of claim 12 wherein the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes provided by:
charging the intrinsic capacitance of the first input node by the current which is representative of the data state of the selected memory cell; and
charging the intrinsic capacitance of the second input node by the reference current.
19. The integrated circuit device of claim 12 further including voltage level shifter circuitry, coupled between the bit line and the cross-coupled sense amplifier.
20. An integrated circuit device comprising:
a bit line having a plurality of memory cells coupled thereto wherein each memory cell includes an electrically floating body transistor including:
a source region;
a drain region;
a body region disposed between the source region and the drain region,
wherein the body region is electrically floating; and
a gate disposed over the body region; and
wherein each memory cell includes:
a first data state representative of a first charge in the body region of the transistor; and
a second data state representative of a second charge in the body region of the transistor;
a cross-coupled sense amplifier including first and second input nodes, each input node having an intrinsic capacitance, wherein the cross-coupled sense amplifier further includes:
a pitch that is substantially the same as a pitch of the bit line;
a first transistor having first and second regions and a gate, wherein the first region is connected to or forms a part of the first input node, and wherein the first input node is coupled to the bit line to receive a current which is representative of a data state of a selected memory cell, wherein the selected memory cell is one of the plurality of memory cells which are coupled to the bit line; and
a second transistor having first and second regions and a gate, wherein the first region of the second transistor is connected to or forms a part of the second input node, and wherein the second input node receives a reference current; and reference current generation circuitry, coupled to the second input node of the sense amplifier, to generate a current that is representative of the reference current;
first current mirror circuit having an input which is coupled to the bit line and an output which is coupled to the first input node; and
wherein, in operation, the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes.
21. The integrated circuit device of claim 20 wherein:
the gate of the first transistor of the sense amplifier is connected to the second input node and the gate of the second transistor of the sense amplifier is connected to the first input node;
the second region of the first transistor of the sense amplifier is connected to a first reference voltage and the second region of the second transistor of the sense amplifier is connected to the first reference voltage; and
wherein the cross-coupled sense amplifier further includes third and fourth transistors, each having first and second regions and a gate, wherein:
the first regions of the third and fourth transistors are connected and coupled to a second reference voltage;
the second region of the third transistor is connected to or forms a part of the first input node;
the second region of the fourth transistor is connected to or forms a part of the second input node;
the gate of the third transistor is connected to the second input node; and
the gate of the fourth transistor is connected to the first input node.
22. The integrated circuit device of claim 20 further including a second current mirror circuit coupled between the reference current generation circuitry and the second input node wherein the second current mirror circuit includes an input which is coupled to the reference current generation circuitry and an output which is coupled to the second input node.
23. The integrated circuit device of claim 20 further including:
write back circuitry, coupled to the first and second input nodes of the cross-coupled sense amplifier, to restore the data state of the selected memory cell or write a new data state into the selected memory cell; and
voltage level shifter circuitry, coupled between the write back circuitry and the cross-coupled sense amplifier.
24. The integrated circuit device of claim 20 further including write back circuitry, coupled to the cross-coupled sense amplifier, to restore the data state of the selected memory cell or write a new data state into the selected memory cell.
25. The integrated circuit device of claim 20 wherein the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes provided by:
charging the intrinsic capacitance of the first input node by the current which is representative of the data state of the selected memory cell; and
charging the intrinsic capacitance of the second input node by the reference current.
26. The integrated circuit device of claim 20 wherein the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes provided by:
(1a) charging the intrinsic capacitance of the first input node by the current which is representative of the data state of the selected memory cell, and (1b) charging the intrinsic capacitance of the second input node by the reference current; or
(2)writing to cross-coupled sense amplifier through input/output circuitry.
27. An integrated circuit device comprising:
a bit line having a plurality of memory cells coupled thereto wherein each memory cell includes an electrically floating body transistor including:
source region;
a drain region;
a body region disposed between the source region and the drain region,
wherein the body region is electrically floating; and
a gate disposed over the body region; and
wherein each memory cell includes:
a first data state representative of a first charge in the body region of the transistor; and
a second date state representative of a second charge in the body region of the transistor;
a cross-coupled sense amplifier including first and second input nodes, each input node having an intrinsic capacitance, wherein the cross-coupled sense amplifier includes:
a first transistor having first and second regions and a gate, wherein the first region is connected to or forms a part of the first input node, and wherein the first input node is coupled to the bit line to receive a current which is representative of a data state of a selected memory cell, wherein the selected memory cell is one of the plurality of memory cells which are coupled to the bit line; and
a second transistor having first and second regions and a gate, wherein the first region of the second transistor is connected to or forms a part of the second input node, and wherein the second input node receives a reference current; and reference current generation circuitry, coupled to the second input node of the sense amplifier, to generate a current that is representative of the reference current;
write back circuitry, coupled to the cross-coupled sense amplifier and the bit line, to restore the data state of the selected memory cell or write a different data state into the selected memory cell;
voltage level shifter circuitry coupled to the write back circuitry; and
wherein, in operation, the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes.
28. The integrated circuit device of claim 27 wherein:
the gate of the first transistor of the sense amplifier is connected to the second input node and the gate of the second transistor of the sense amplifier is connected to the first input node; and
the second region of the first transistor of the sense amplifier is connected to a first reference voltage and the second region of the second transistor of the sense amplifier is connected to the first reference voltage.
29. The integrated circuit device of claim 27 wherein the cross-coupled sense amplifier further includes third and fourth transistors, each having first and second regions and a gate, wherein:
the first regions of the third and fourth transistors are connected and coupled to a second reference voltage;
the second region of the third transistor is connected to or forms a part of the first input node;
the second region of the fourth transistor is connected to or forms a part of the second input node;
the gate of the third transistor is connected to the second input node; and
the gate of the fourth transistor is connected to the first input node.
30. The integrated circuit device of claim 27 further including a current mirror circuit coupled between the bit line and the first input node.
31. The integrated circuit device of claim 30 wherein the current mirror circuit includes an input which is connected to the bit line and an output which is connected to the first input node.
32. The integrated circuit device of claim 30 wherein the first current mirror circuit, in operation, decouples the bit line capacitance from the first input node.
33. The integrated circuit device of claim 27 further including a current mirror circuit coupled between the reference current generation circuitry and the second input node.
34. The integrated circuit device of claim 33 wherein the current mirror circuit includes an input which is connected to the reference current generation circuitry and an output which is connected to the second input node.
35. The integrated circuit device of claim 27 wherein the reference current generation circuitry includes a plurality of reference cells.
36. The integrated circuit device of claim 27 wherein the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes provided by:
charging or discharging the intrinsic capacitance of the first input node by the current which is representative of the data state of the selected memory cell; and
charging or discharging the intrinsic capacitance of the second input node by the reference current.
37. An integrated circuit device comprising:
a bit line having a plurality of memory cells coupled thereto wherein each memory cell includes an electrically floating body transistor including:
a source region;
a drain region;
a body region disposed between the source region and the drain region,
wherein the body region is electrically floating; and
a gate disposed over the body region; and
wherein each memory cell includes:
a first data state representative of a first charge in the body region of the transistor; and
a second data state representative of a second charge in the body region of the transistor;
a cross-coupled sense amplifier including first and second input nodes, each input node having an intrinsic capacitance, wherein the cross-coupled sense amplifier further includes:
a pitch that is substantially the same as a pitch of the bit line;
a first transistor having first and second regions and a gate, wherein the first region is connected to or forms a part of the first input node, and wherein the first input node is coupled to the bit line to receive a current which is representative of a data state of a selected memory cell, wherein the selected memory cell is one of the plurality of memory cells which are coupled to the bit line; and
a second transistor having first and second regions and a gate, wherein the first region of the second transistor is connected to or forms a part of the second input node, and wherein the second input node receives a reference current; and
wherein, in operation, the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes.
38. The integrated circuit device of claim 37 further including a current mirror circuit coupled between the bit line and the first input node.
39. The integrated circuit device of claim 38 wherein the current mirror circuit includes an input which is coupled to the bit line and an output which is coupled to the first input node.
40. The integrated circuit device of claim 39 wherein the current mirror circuit, in operation, decouples the bit line capacitance from the first input node.
41. The integrated circuit device of claim 37 further including a current mirror circuit coupled between the reference current generation circuitry and the second input node.
42. The integrated circuit device of claim 41 wherein the current mirror circuit includes an input which is coupled to the reference current generation circuitry and an output which is coupled to the second input node.
43. The integrated circuit device of claim 37 wherein the reference current generation circuitry includes a plurality of reference cells.
44. The integrated circuit device of claim 37 wherein the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes provided by:
charging or discharging the intrinsic capacitance of the first input node by the current which is representative of the data state of the selected memory cell; and
charging or discharging the intrinsic capacitance of the second input node by the reference current.
45. The integrated circuit device of claim 37 further including:
write back circuitry, coupled to the cross-coupled sense amplifier, to restore the data state of the selected memory cell or write a new data state into the selected memory cell; and
voltage level shifter circuitry coupled between the write back circuitry and the cross-coupled sense amplifier.
46. The integrated circuit device of claim 37 further including write back circuitry, coupled to the first and second input nodes of the cross-coupled sense amplifier, to restore the data state of the selected memory cell or write a new data state into the selected memory cell.
47. The integrated circuit device of claim 37 further including voltage level shifter circuitry coupled between the bit line and the cross-coupled sense amplifier.
48. The integrated circuit device of claim 37 wherein the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes provided by:
charging the intrinsic capacitance of the first input node by the current which is representative of the data state of the selected memory cell; and
charging the intrinsic capacitance of the second input node by the reference current.
49. The integrated circuit device of claim 37 wherein the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes provided by:
(1a) charging the intrinsic capacitance of the first input node by the current which is representative of the data state of the selected memory cell, and (1b) charging the intrinsic capacitance of the second input node by the reference current; or
(2) writing to cross-coupled sense amplifier through input/output circuitry.
50. An integrated circuit device comprising:
a bit line having a plurality of memory cells coupled thereto wherein each memory cell includes an electrically floating body transistor including:
a source region;
a drain region;
a body region disposed between the source region and the drain region,
wherein the body region is electrically floating; and
a gate disposed over the body region; and
wherein each memory cell includes:
a first data state representative of a first charge in the body region of the transistor; and
a second data state representative of a second charge in the body region of the transistor;
a cross-coupled sense amplifier including first and second input nodes, each input node having an intrinsic capacitance, wherein the cross-coupled sense amplifier includes:
a first transistor having first and second regions and a gate, wherein the first region is connected to or forms a part of the first input node, and wherein the first input node is coupled to the bit line to receive a current which is representative of a data state of a selected memory cell, wherein the selected memory cell is one of the plurality of memory cells which are coupled to the bit line; and
a second transistor having first and second regions and a gate, wherein the first region of the second transistor is connected to or forms a part of the second input node, and wherein the second input node receives a reference current; and reference current generation circuitry, coupled to the second input node of the sense amplifier, to generate a current that is representative of the reference current;
voltage level shifter circuitry coupled between the bit line and the cross-coupled sense amplifier; and
wherein, in operation, the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes.
51. The integrated circuit device of claim 50 wherein:
the gate of the first transistor of the sense amplifier is connected to the second input node and the gate of the second transistor of the sense amplifier is connected to the first input node; and
the second region of the first transistor of the sense amplifier is connected to a first reference voltage and the second region of the second transistor of the sense amplifier is connected to the first reference voltage.
52. The integrated circuit device of claim 51 wherein the cross-coupled sense amplifier further includes third and fourth transistors, each having first and second regions and a gate, wherein:
the first regions of the third and fourth transistors are connected and coupled to a second reference voltage;
the second region of the third transistor is connected to or forms a part of the first input node;
the second region of the fourth transistor is connected to or forms a part of the second input node;
the gate of the third transistor is connected to the second input node; and
the gate of the fourth transistor is connected to the first input node.
53. The integrated circuit device of claim 50 further including a current mirror circuit coupled between the bit line and the first input node.
54. The integrated circuit device of claim 53 wherein the current mirror circuit includes an input which is connected to the bit line and an output which is connected to the first input node.
55. The integrated circuit device of claim 53 wherein the current mirror circuit, in operation, decouples the bit line capacitance from the first input node.
56. The integrated circuit device of claim 50 further including a current mirror circuit coupled between the reference current generation circuitry and the second input node.
57. The integrated circuit device of claim 56 wherein the current mirror circuit includes an input which is coupled to the reference current generation circuitry and an output which is coupled to the second input node.
58. The integrated circuit device of claim 50 wherein the reference current generation circuitry includes a plurality of reference cells.
59. The integrated circuit device of claim 50 wherein the cross-coupled sense amplifier determines the data state of the selected memory cell based on voltages developed on the first and second input nodes provided by:
charging or discharging the intrinsic capacitance of the first input node by the current which is representative of the data state of the selected memory cell; and
charging or discharging the intrinsic capacitance of the second input node by the reference current.