Selection device for a semiconductor memory device
View Patent ↗A selection device for a semiconductor memory device for preventing voltage drops caused by read currents in a column multiplexer of a semiconductor memory device includes switch devices having two switch elements. Associated bit lines can be interlinked with a potential sampling connection or a current feed connection of a respective associated sense amplifier by the first and the second switch element.
1. In a semiconductor memory device having a memory area with storage elements, selectable access line devices respectively connected to the storage elements, and a sense-amplifier device with a potential-sensing connection and a current-supply connection, a selection device comprising:
switching devices each associated with and connected to a respective one of the access line devices for accessing the storage elements in the memory area, each of said switching devices:
controllably connecting, upon selection, the respective associated access line device to the potential-sensing connection for detecting an electrical potential on the respective access line device and to the current-supply connection for supplying a compensating current to the respective access line device; and
having first and second switching elements and, during operation, said first switching element connecting the associated access line device to the potential-sensing connection and said second switching element connecting the associated access line device to the current-supply connection.
2. The selection device according to claim 1 , wherein said first and second switching elements are respectively connected in parallel with one another.
3. The selection device according to claim 1 , wherein said first and second switching elements each produce two switching states.
4. The selection device according to claim 3 , wherein said two switching states include a connected switching state and a disconnected switching state.
5. The selection device according to claim 3 , wherein said two switching states include a contact-making switching state and an isolating switching state.
6. The selection device according to claim 3 , wherein, in a first of said two switching states, said first switching element makes a comparatively low-impedance contact.
7. The selection device according to claim 3 , wherein, in a first of said two switching states, said first switching element makes a comparatively low-impedance contact to the potential-sensing connection on the sense-amplifier device.
8. The selection device according to claim 3 , wherein, in a first of said two switching states, said first switching element makes a low-impedance contact as compared to a contact of said second switching element.
9. The selection device according to claim 3 , wherein, in a first of said two switching states, said first switching element makes a low-impedance contact to the potential-sensing connection as compared to a contact of said second switching element.
10. The selection device according to claim 1 , wherein said first and second switching elements are transistor devices.
11. The selection device according to claim 1 , wherein said first and second switching elements are MOSFETs.
12. The selection device according to claim 10 , wherein respective drain regions of said transistor devices are connected to the respectively connected one of the access line devices.
13. The selection device according to claim 12 , wherein source regions of said transistor devices are each respectively connected to one of the respective potential connection and the respective current-supply connection on the associated sense-amplifier device.
14. The selection device according to claim 10 , wherein a source region of said transistor devices are each respectively connected to one of the respective potential connection and the respective current-supply connection on the associated sense-amplifier device.
15. The selection device according to claim 10 , wherein:
the sense-amplifier device is a single common sense-amplifier device;
said first and second switching elements have output connections; and
a common line device respectively connects said output connections to said single sense-amplifier device.
16. The selection device according to claim 10 , wherein:
the sense-amplifier device is a single common sense-amplifier device;
said first and second switching elements have source regions; and
a common line device respectively connects said source regions to said single sense-amplifier device.
17. The selection device according to claim 1 , wherein:
the access line devices are bit line devices; and
said switching devices are each associated with and connected to a respective one of the bit line devices.
18. In a semiconductor memory device having a memory area with storage elements, selectable access line devices including bit line devices respectively connected to the storage elements, and a sense-amplifier device with a potential-sensing connection and a current-supply connection, a selection device comprising:
switching devices each associated with and connected to a respective one of the bit line devices for accessing the storage elements in the memory area, each of said switching devices:
controllably connecting, upon selection, the respective associated bit line device to the potential-sensing connection for detecting an electrical potential on the respective bit line device and to the current-supply connection for supplying a compensating current to the respective bit line device; and
having first and second switching elements and, during operation, said first switching element connecting the associated bit line device to the potential-sensing connection and said second switching element connecting the associated bit line device to the current-supply connection.
19. A semiconductor memory device, comprising:
a memory area having storage elements;
selectable access line devices respectively connected to said storage elements;
a sense-amplifier device having a potential-sensing connection and a current-supply connection, said sense-amplifier device connected to said access line devices; and
a selection device having switching devices each associated with and connected to a respective one of said access line devices for accessing the storage elements in the memory area, each of said switching devices:
controllably connecting, upon selection, the respective associated access line device to the potential-sensing connection for detecting an electrical potential on the respective access line device and to the current-supply connection for supplying a compensating current to the respective access line device; and
having first and second switching elements and, during operation, said first switching element connecting the associated access line device to the potential-sensing connection and said second switching element connecting the associated access line device to the current-supply connection.