Non-volatile semiconductor memory device having sense amplifier with increased speed
View Patent ↗In the non-volatile semiconductor memory device having a sense amplifier for sensing data stored in a selected memory cell by comparing cell current differences from a reference cell, a current sink unit coupled in parallel with a reference line and a data line are provided. The reference line connects between the reference cell and the sense amplifier, and the data line connects between the selected memory cell and the sense amplifier, where the current sink unit together increases currents of the reference line and the data line. Also, the device includes a sink current control unit having a configuration of a current mirror with the current sink unit, the sink current control unit consisting of a switching unit and being for controlling a sink current of the current sink unit. The device improves data sensing speed and controls sensing current in conformity with the characteristics of a memory cell.
1. A non-volatile semiconductor memory device having a sense amplifier that senses data stored in a selected memory cell by comparing cell current differences to a reference cell, the semiconductor memory device comprising:
a current sink unit coupled in parallel with a reference line and a data line, wherein the reference line connects between the reference cell and the sense amplifier, and the data line connects between the selected memory cell and the sense amplifier, wherein the current sink unit modifies currents of the reference line and the data line; and
a sink current control unit having a configuration of a current mirror together with the current sink unit, the sink current control unit having a switching unit for controlling a sink current of the current sink unit that is responsive to switching signals generated by the sink current control unit.
2. The device as claimed in claim 1 , wherein the sense amplifier is a current mirror type.
3. The device as claimed in claim 1 , wherein the current sink unit comprises:
a first current sink part coupled in parallel to the reference line for connecting between the reference cell and the sense amplifier, the first current sink part for increasing a current of the reference line; and
a second current sink part coupled in parallel to the data line for connecting between the selected memory cell and the sense amplifier, the second current sink part for increasing a current of the data line.
4. A non-volatile semiconductor memory device having a sense amplifier that senses data stored in a selected memory cell by comparing cell current differences to a reference cell, the semiconductor memory device comprising:
a current sink unit coupled in parallel with a reference line and a data line, wherein the reference line connects between the reference cell and the sense amplifier, and the data line connects between the selected memory cell and the sense amplifier, wherein the current sink unit together increases currents of the reference line and the data line; and
a sink current control unit having a configuration of a current mirror together with the current sink unit, the sink current control unit having a switching unit for controlling a sink current of the current sink unit,
wherein the current sink unit comprises:
a first current sink part coupled in parallel to the reference line for connecting between the reference cell and the sense amplifier, the first current sink part for increasing a current of the reference line; and
a second current sink part coupled in parallel to the data line for connecting between the selected memory cell and the sense amplifier, the second current sink part for increasing a current of the data line, wherein the first current sink part is constructed of a first NMOS transistor connected to the reference line and responding to a sink current enable signal, and a second NMOS transistor connected in series to the first NMOS transistor.
5. The device as claimed in claim 4 , wherein the second current sink part is constructed of a third NMOS transistor connected to the data line and responding to the sink current enable signal, and a fourth NMOS transistor connected in series to the third NMOS transistor.
6. The device as claimed in claim 5 , wherein the sink current control unit comprises a fifth NMOS transistor that has a current mirror type with the second NMOS transistor and the fourth NMOS transistor.
7. The device as claimed in claim 6 , wherein the sink current control unit comprises a plurality of resistance elements connected between the fifth NMOS transistor and a power source, a switching unit for controlling a connection state of the resistance elements, and a switching control part for controlling the switching unit.
8. The device as claimed in claim 7 , wherein the switching control part controls an individual connection state of the resistance elements by an opening or closing of a fuse.
9. The device as claimed in claim 8 , wherein the first NMOS transistor and the third NMOS transistor have the same characteristics and size.
10. The device as claimed in claim 8 , wherein the second NMOS transistor, the fourth NMOS transistor and the fifth NMOS transistor have the same characteristics and size.
11. A non-volatile semiconductor memory device having a sense amplifier that senses data stored in a selected memory cell by comparing cell current differences to a reference cell, the semiconductor memory device comprising:
a sink current control unit for generating a control signal that controls a sink current, the sink current control unit including a switching unit; and
a current sink unit coupled in parallel with a reference line and a data line, wherein the reference line connects between the reference cell and the sense amplifier and the data line connects between the selected memory cell and the sense amplifier, where the current sink unit has a configuration of a current mirror with the sink current control unit, and modifies currents of the reference line and the data line in response to a control signal of the sink current control unit that is responsive to switching signals generated by the sink current control unit.
12. The device as claimed in claim 11 , wherein the sense amplifier is a current mirror type.
13. The device as claimed in claim 12 , wherein the current sink unit comprises:
a first current sink part coupled in parallel to the reference line for connecting between the reference cell and the sense amplifier, the first current sink part for increasing a current of the reference line; and
a second current sink part coupled in parallel to the data line for connecting between the selected memory cell and the sense amplifier, the second current sink part for increasing a current of the data line.
14. A non-volatile semiconductor memory device having a sense amplifier that senses data stored in a selected memory cell by comparing cell current differences to a reference cell, the semiconductor memory device comprising:
a sink current control unit for generating a control signal that controls a sink current, the sink current control unit including a switching unit; and
a current sink unit coupled in parallel with a reference line and a data line, wherein the reference line connects between the reference cell and the sense amplifier and the data line connects between the selected memory cell and the sense amplifier, where the current sink unit has a configuration of a current mirror with the sink current control unit, and together increases currents of the reference line and the data line in response to a control signal of the sink current control unit,
wherein the current sink unit comprises:
a first current sink part coupled in parallel to the reference line for connecting between the reference cell and the sense amplifier, the first current sink part for increasing a current of the reference line; and
a second current sink part coupled in parallel to the data line for connecting between the selected memory cell and the sense amplifier, the second current sink part for increasing a current of the data line, wherein the first current sink part is constructed of a first NMOS transistor connected to the reference line and responding to a sink current enable signal, and a second NMOS transistor connected in series to the first NMOS transistor.
15. The device as claimed in claim 14 , wherein the second current sink part is constructed of a third NMOS transistor connected to the data line and responding to the sink current enable signal, and a fourth NMOS transistor connected in series to the third NMOS transistor.
16. The device as claimed in claim 15 , wherein the sink current control unit comprises a fifth NMOS transistor that has a current mirror type with the second NMOS transistor and the fourth NMOS transistor.
17. The device as claimed in claim 16 , wherein the sink current control unit comprises a plurality of resistance elements connected between the fifth NMOS transistor and a power source, a switching unit for controlling a connection state of the resistance elements, and a switching control part for controlling the switching unit.
18. The device as claimed in claim 17 , wherein the switching control part controls an individual connection state of the resistance elements by an opening or closing of a fuse.
19. The device as claimed in claim 18 , wherein the first NMOS transistor and the third NMOS transistor have the same characteristics and size.
20. The device as claimed in claim 18 , wherein the second NMOS transistor, the fourth NMOS transistor and the fifth NMOS transistor have the same characteristics and size.
21. A non-volatile semiconductor memory device having a sense amplifier that senses data stored in a selected memory cell by comparing cell current differences to a reference cell, the semiconductor memory device comprising:
a current sink unit coupled in parallel with a reference line and a data line, wherein the reference line connects between the reference cell and the sense amplifier, and the data line connects between the selected memory cell and the sense amplifier, wherein the current sink unit together increases currents of the reference line and the data line; and
a sink current control unit having a configuration of a current mirror together with the current sink unit, the sink current control unit having a switching unit for controlling a sink current of the current sink unit,
wherein the current sink unit comprises:
a first current sink part coupled in parallel to the reference line for connecting between the reference cell and the sense amplifier, the first current sink part for increasing a current of the reference line; and
a second current sink part coupled in parallel to the data line for connecting between the selected memory cell and the sense amplifier, the second current sink part for increasing a current of the data line, wherein the first current sink part is constructed of a first transistor connected to the reference line and responding to a sink current enable signal.
22. The device as claimed in claim 21 , wherein the second current sink part is constructed of a second transistor connected to the data line and responding to the sink current enable signal.
23. The device as claimed in claim 21 , wherein the current sink unit is responsive to a sink current enable signal.