Method and circuitry to generate a reference current for reading a memory cell, and device implementing same
View Patent ↗There are many inventions disclosed herein. In one aspect, the present inventions are directed to methods and circuitry to control, adjust, determine and/or modify the absolute and/or relative positioning or location (i.e., absolute or relative amount) of reference current which is employed by sensing circuitry to sense the data state of a memory cell during a read operation of one or more memory cells. The control, adjustment, determination and/or modification of the reference current levels may be implemented using many different, distinct and/or diverse techniques and circuitry, including both analog and digital techniques and circuitry.
1. A reference current generation circuit to generate a reference current for data sensing circuitry, the reference current generation circuit comprising:
a plurality of reference networks, wherein each reference network includes:
a current driver including a transistor having an output which is coupled to a signal line; and
a reference cell network wherein the reference cell network includes a plurality of reference cells, and wherein each reference cell is programmed to one of a plurality of data states, and wherein:
(i) a majority of the reference cells of at least one of the reference cell networks are programmed to a second data state and (ii) a minority of the reference cells of the at least one of the reference cell network is/are programmed to a first data state; and
an equal number of the reference cells of at least one of the reference cell networks are programmed to a first data state and to a second data state; and
a reference current driver including a transistor which is coupled to the plurality of reference networks via the signal line to generate the reference current.
2. The reference current generation circuit of claim 1 wherein a majority of the reference cells of a plurality of the reference cell networks are programmed to the second data state and a minority of the reference cells of the at least one of the reference cell network is/are programmed to the first data state.
3. The reference current generation circuit of claim 1 wherein all of the reference cells of the at least one reference cell network are programmed to the second data state.
4. The reference current generation circuit of claim 1 further including control data signal lines, coupled to the at least one reference cell network, to program the reference cells of the at least one reference cell network.
5. The reference current generation circuit of claim 4 further including memory circuitry, coupled to the control data signal lines, to store control data which is applied to the control data signal lines to program the reference cells of the at least one reference cell network.
6. The reference current generation circuit of claim 5 wherein the memory circuitry includes one or more (i) registers and/or (ii) fuses or anti-fuses.
7. The reference current generation circuit of claim 4 further including control circuitry, coupled to the control data signal lines, to determine the control data which is applied to the control data signal lines to program the reference cells of the at least one reference cell network.
8. The reference current generation circuit of claim 4 wherein the control data is fixed.
9. The reference current generation circuit of claim 4 wherein the control data is applied to the control data signal lines to program the reference cells of the at least one reference cell network during start-up and/or initialization.
10. The reference current generation circuit of claim 1 wherein the transistor of the current driver of each reference network and the transistor of each reference current driver include device geometries and wherein the device geometry of the transistor of the current driver is more than twice the device geometry of the transistor of the reference current driver.
11. The reference current generation circuit of claim 1 wherein the transistor of each current driver of each reference network includes a device geometry and wherein the device geometry of the transistor of each current driver is at least substantially the same.
12. The reference current generation circuit of claim 1 wherein the transistor of each current driver of each reference network includes a device geometry and wherein the device geometry of the transistor of the current driver of at least one reference network is substantially different from a device geometry of the transistors of a plurality of current drivers of other reference networks.
13. A reference current generation circuit to generate a reference current for data sensing circuitry, the reference current generation circuit comprising:
a plurality of reference networks, wherein each reference network includes:
a current driver having an output coupled to a signal line; and
a reference cell network wherein the reference cell network includes a plurality of reference cells, and wherein
each reference cell is programmed in (i) a first data state which corresponds to a first charge in the body region of the transistor of the reference cell, or (ii) a second data state which corresponds to a second charge in the body region of the transistor of the reference cell;
a majority of the reference cells of at least one of the reference cell networks are programmed to a second data state and a minority of the reference cells of the at least one of the reference cell network is/are programmed to a first data state; and
an equal number of the reference cells of at least one of the reference cell networks are programmed to a first data state and to a second data state; and
a reference current driver coupled to the plurality of reference networks via the signal line to generate the reference current.
14. The reference current generation circuit of claim 13 wherein a majority of the reference cells of a plurality of the reference cell networks are programmed to the second data state and a minority of the reference cells of the at least one of the reference cell network is/are programmed to the first data state.
15. The reference current generation circuit of claim 13 wherein all of the reference cells of the at least one reference cell network are programmed to the second data state.
16. The reference current generation circuit of claim 13 further including memory circuitry to store control data which is applied to at least one reference cell network to program the reference cells of at least one reference cell network.
17. The reference current generation circuit of claim 16 wherein the memory circuitry includes one or more (i) registers and/or (ii) fuses or anti-fuses.
18. The reference current generation circuit of claim 13 further including control circuitry to determine the control data which is applied to at least one reference cell network to program the reference cells of at least one reference cell network.
19. The reference current generation circuit of claim 13 wherein one or more of the reference cells are programmed during initialization and/or operation.
20. The reference current generation circuit of claim 13 wherein the data state of the reference cells is fixed.
21. A reference current generation circuit to generate a reference current for data sensing circuitry, the reference current generation circuit comprising:
a plurality of reference networks, wherein each reference network includes:
a current driver including a transistor having an output which is coupled to a signal line; and
a reference cell network wherein the reference cell network includes a plurality of reference cells, and wherein each reference cell is programmed to one of a plurality of data states and includes a transistor having an electrically floating body region, and wherein:
each transistor of each reference cell is programmed in (i) a first data state which corresponds to a first charge in the body region of the transistor of the reference cell, or (ii) a second data state which corresponds to a second charge in the body region of the transistor of the reference cell; and
each transistor of a majority of the reference cells of at least one of the reference cell networks is programmed to the second data state and each transistor of a minority of the reference cells of the at least one of the reference cell network is/are programmed to the first data state; and
a reference current driver including a transistor which is coupled to the plurality of reference networks via the signal line to generate the reference current for the data sensing circuitry.
22. The reference current generation circuit of claim 21 wherein in a plurality of reference cell networks an equal number of the transistors of the reference cells are programmed to a first data state and to a second data state.
23. The reference current generation circuit of claim 21 wherein the transistors of all of the reference cells of the at least one reference cell network are programmed to a second data state.
24. The reference current generation circuit of claim 21 further including memory circuitry to store control data which is applied to at least one reference cell network to program the transistor of each reference cell of at least one reference cell network.
25. The reference current generation circuit of claim 21 further including control circuitry to determine the control data which is applied to at least one reference cell network to program the transistor of each reference cell of at least one reference cell network.
26. The reference current generation circuit of claim 21 wherein the transistors of one or more of the reference cells are programmed during initialization.
27. The reference current generation circuit of claim 21 wherein the data state of the transistor of each reference cell of the plurality of reference cell networks is fixed.
28. The reference current generation circuit of claim 21 wherein the transistor of the current driver of each reference network and the transistor of each reference current driver include device geometries and wherein the device geometry of the transistor of the current driver is more than twice the device geometry of the transistor of the reference current driver.
29. The reference current generation circuit of claim 21 wherein the transistor of each current driver includes a device geometry and wherein the device geometry of the transistor of each current driver is at least substantially the same.
30. The reference current generation circuit of claim 21 wherein the transistor of each current driver of each reference network includes a device geometry and wherein the device geometry of the transistor of the current driver of at least one reference network is substantially different from a device geometry of the transistor of the current driver of each of a plurality of the reference networks.
31. A reference current generation circuit to generate a reference current for data sensing circuitry, the reference current generation circuit comprising:
a plurality of reference networks, wherein each reference network includes:
a current driver including a transistor having an output which is coupled to a signal line, wherein the transistor of each current driver includes a device geometry; and
a reference cell network wherein the reference cell network includes a plurality of reference cells, and wherein each reference cell is programmed to one of a plurality of data states and includes a transistor having an electrically floating body region, and wherein:
each transistor of each reference cell is programmed in (i) a first data state which corresponds to a first charge in the body region of the transistor of the reference cell, or (ii) a second data state which corresponds to a second charge in the body region of the transistor of the reference cell; and
a reference current driver including a transistor which is coupled to the plurality of reference networks via the signal line to generate the reference current for the data sensing circuitry;
wherein:
the transistor of the reference current driver includes a device geometry;
the transistor of each current driver of each reference network includes a device geometry; and
the device geometry of the transistor of each current driver is more than twice the device geometry of the transistor of the reference current driver.
32. The reference current generation circuit of claim 31 wherein the device geometry of each transistor of each current driver of each reference network is at least substantially the same.
33. The reference current generation circuit of claim 31 wherein each transistor of a majority of the reference cells of at least one of the reference cell network is programmed to the second data state and each transistor of a minority of the reference cells of the reference cell network is/are programmed to the first data state.
34. The reference current generation circuit of claim 31 wherein in a plurality of reference cell networks an equal number of the transistors of the reference cells are programmed to a first data state and to a second data state.