Line driver circuit and method with standby mode of operation

• US 8,072,834 B2
• Filed: 08/25/2006
• Issued: 12/06/2011
• Est. Priority Date: 08/25/2005
• Status: Active Grant

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Khamesra, Arun, Kothandaraman, Badrinarayanan
• Primary Examiner(s): NGUYEN, VAN THU T
• Application Number:
  US11/510,347
• Publication Number:
  US 20070140037A1
• Time in Patent Office: 1,929 Days
• Field of Search: 365/226, 365/229.X, 365/230.06 O, 365/229, 365/230.06
• US Class Current: 365/230.06
• CPC Class Codes: G11C 5/148 Details of power up or power down circuits, standby circuits or recovery circuits
• CPC Class Codes: G11C 8/08 Word line control circuits, e.g. drivers, boosters, pull-up circuits, pull-down circuits, precharging circuits, for word lines

Abstract

A line driver circuit can include an integrated circuit substrate of a first conductivity type having at least a first and a second well of a second conductivity type formed therein. The second well can be coupled to a first power supply node. A first transistor can be formed in the first well having a source coupled to a first input signal node, a drain coupled to a conductive line, and a gate coupled to a second input signal node. A second transistor can have a source coupled to a second power supply node, a drain coupled to the conductive line, and a gate coupled to the second input signal node. A third transistor can be formed in the second well and have a source coupled to the first power supply node, a drain coupled to the first well, and a gate coupled to receive a mode signal.

Claims

1. A driver circuit arrangement, comprising:

at least one driver circuit, comprising

a first transistor of a first conductivity type having a source coupled to receive a first signal driven between a first potential and a second potential, and including a bulk portion containing the source and a drain of the first transistor;

a second transistor of a second conductivity type having a drain coupled to the drain of the first transistor and a source coupled to a first power supply node that is coupled to receive the first potential;

a third transistor of the second conductivity type having a drain coupled to the drain of the first transistor and a source coupled to the first power supply node; and

a control device comprising a fourth transistor of the first conductivity type having a source coupled to a second power supply node and a drain coupled to the bulk portion of the first transistor, the control device configured to connect the bulk portion of the first transistor to the second power supply in an active mode of operation, and in a standby mode of operation to allow the bulk portion of the first transistor to electrically float and thereby electrically isolate the bulk portion of the first transistor from any direct voltage source.

2. The driver circuit arrangement of claim 1, wherein:

the first transistor comprises a p-channel insulated gate field effect transistor (IGFET); and

the second and third transistors comprise n-channel IGFETs.

3. The driver circuit arrangement of claim 1, wherein:

the driver circuit arrangement comprises at least one other driver circuit comprising at least one other first transistor; and

the control device allows bulk portions of the first transistor and the at least one other first transistor to electrically float in the second mode of operation.

4. The driver circuit arrangement of claim 1, the fourth transistor having a drain coupled to the bulk of the first transistor and a gate coupled to receive a mode signal.

5. The driver circuit arrangement of claim 4, wherein:

the mode signal is driven to the second potential in the first mode of operation and to the first potential in a second mode of operation.

6. The driver circuit arrangement of claim 1, wherein:

the second transistor includes a gate coupled to receive a second signal that is the inverse of the first signal.

7. The driver circuit arrangement of claim 1, wherein:

the at least a one driver circuit further includes

a word line coupled to the drain of the first transistor, and

a plurality of memory cells coupled to the word line.

8. The driver circuit arrangement of claim 1, wherein:

the at least one driver circuit comprises;

a sub-word line coupled the drain of the first transistor,

one or more memory cells coupled to the sub-word line; and

a global word line coupled to the gates of the first and second transistors.

9. The driver circuit arrangement of claim 8, further including:

a global word line decoder circuit that activates one of a plurality of global word line signals in response to different combinations of address input signals;

the global word line being coupled to receive one of the global word line signals; and

a block decoder circuit that activates the first signal in response to particular combinations of block select signals.

10. A line driver circuit, comprising:

an integrated circuit substrate of a first conductivity type having at least a first well and a second well of a second conductivity type formed therein, the second well being coupled to a first power supply node;

a first transistor formed in the first well having a source coupled to a first input signal node, a drain coupled to a conductive line, and a gate coupled to a second input signal node;

a second transistor having a source coupled to a second power supply node, a drain coupled to the conductive line, and a gate coupled to the second input signal node;

a third transistor formed in the second well having a source coupled to the first power supply node, a drain coupled to the first well, and a gate coupled to a mode signal node, the third transistor couples the first well to the first power supply node during an active mode of operation of the line driver circuit in response to the mode signal having a first value and allows the first well to electrically float thereby electrically isolating the first well during a standby mode of operation of the line driver circuit in response to the mode signal having a second value.

11. The line driver circuit of claim 10, wherein:

the substrate is a p-type substrate and the first and second wells are n-type wells; and

the first transistor and third transistor are p-channel insulated gate field effect transistors (IGFETs), and the second transistor is an n-channel IGFET.

12. The line driver circuit of claim 10, further including:

a fourth transistor having a source coupled to the second power supply node, a drain coupled to the conductive line, and a gate coupled to a third input signal node;

wherein

the first input signal node receives a first input signal and the third input signal node receives a third input signal that is the inverse of the first input signal.

13. The line driver circuit of claim 10, wherein:

the conductive line comprises a word line coupled to a plurality of memory cells.

14. The line driver circuit of claim 13, further including:

a global word line decoder that drives the second input signal node between at least two levels according to received address values.

15. A line driver circuit, comprising:

an integrated circuit substrate of a first conductivity type having at least a first well and a second well of a second conductivity type formed therein, the second well being coupled to a first power supply node;

a first transistor and a second transistor having source-drain paths connected in series between a select signal node and a second power supply node, the source-drain paths having a common connection to a word line, the word line coupled to a plurality of memory cells;

the first transistor formed in the first well including a gate coupled to a line select signal node, the second transistor including a gate coupled to the line select signal node;

a third transistor formed in the second well having a source coupled to the first power supply node, a drain coupled to the first well, and a gate coupled to a mode signal node;

a fourth transistor having a source drain path coupled between the word line and the second power supply node, and a gate coupled to an inverse select signal node;

wherein;

during an active mode of the line driver circuit, the word line is coupled to the select signal node by the first transistor and the third transistor couples the first well to the first power supply node, and

during a standby mode of the line driver circuit, the word line is coupled to the second power supply node by the fourth transistor and the mode transistor is turned off to allow the first well to electrically float thereby electrically isolating the first well to reduce gate induced drain leakage through the first well.

16. The line driver circuit of claim 15, wherein:

the substrate is a p-type substrate and the first and second wells are n-type wells; and

the first transistor and third transistor are p-channel insulated gate field effect transistors (IGFETs), and the second transistor is an n-channel IGFET.