Sense amplifier

Details Sense amplifier Sense amplifier

1999-01-05

2002-07-16

Smith, Matthew (Department: 2825)

Miscellaneous active electrical nonlinear devices, circuits, and

Specific signal discriminating without subsequent control

By amplitude

C327S057000

Reexamination Certificate

active

06420908

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates generally to semiconductor integrated circuits (ICs). In particular, the invention relates to reducing the size of sense amplifiers used in ICs such as memory ICs.
BACKGROUND OF THE INVENTION
Semiconductor ICs, such as memory ICs, employ sense amplifiers, for example, to read, write, and restore information in the memory cells. A sense amplifier is provided for a bitline pair of the memory IC. During operation, the sense amplifier senses and amplifies a differential voltage between the bitlines of the bitline pair. The differential voltage indicates whether the charge stored in the selected memory cell is a logic 1 or logic 0.
A continuing demand for higher integration and lower manufacturing cost has placed increasing pressures on IC manufacturers to produce smaller and smaller chips. Since the sense amplifiers, in a typical memory IC, contribute to about 10% of the chip size, decreasing the size of a sense amplifier can provide a noticeable reduction in the overall chip size.
Generally, a sense amplifier includes cross-coupled latches for sensing the differential voltage between the bitline pair. The sense amplifier also includes drivers for driving the latches in order to amplify the sensed differential voltage. The drivers are relatively large and contribute significantly to the size of the sense amplifier.
Reducing the size of the drivers can noticeably reduce the size of the sense amplifier. However, the drivers require a minimum dimension due to design requirements. Reducing the size of the drivers to smaller than the minimum dimension can result in a decrease in the performance of the drivers, which adversely impacts the performance or the functionality of the IC.
One technique of reducing the size of the sense amplifier is to locate the drivers outside of the general sense amplifier region. For example, the drivers can be located in the stitch gap region between sense amplifiers of a stitched wordline architecture or in the local wordline driver region between the sense amplifiers in a segmented wordline architecture. Other areas in which the drivers can be located include the row decoder region. However, smaller groundrules have decreased the surface area of the stitch gap or local wordline driver region, making it difficult to accommodate the drivers.
As evidenced from the foregoing discussion, it is desirable to decrease the size of sense amplifiers without decreasing their performance or affecting their functionality.
SUMMARY OF THE INVENTION
The invention relates to reducing the size of sense amplifiers. In one embodiment, an active input signal which activates the driver of the sense amplifier produces an increase in the overdrive voltage to cause the driver to operate in the increased overdrive mode. This enables the use of a smaller driver which facilitates a more efficient layout and/or reduces the size of the sense amplifiers.


REFERENCES:
patent: 4150311 (1979-04-01), Matsuda et al.
patent: 4421996 (1983-12-01), Chuang et al.
patent: 4816706 (1989-03-01), Dhong et al.
patent: 5051959 (1991-09-01), Nakano et al.
patent: 5075571 (1991-12-01), Dhong et al.
patent: 5093808 (1992-03-01), Foss
patent: 5130580 (1992-07-01), Min et al.
patent: 5265047 (1993-11-01), Leung et al.
patent: 5566105 (1996-10-01), Tanaka et al.
patent: 5638333 (1997-06-01), Lee
patent: 5680349 (1997-10-01), Atsumi et al.
patent: 5856945 (1999-01-01), Lee et al.
patent: 5933386 (1999-08-01), Walker et al.
patent: 5949720 (1999-09-01), Brady
patent: 6021083 (2000-01-01), Shiau et al.
patent: 6088275 (2000-07-01), Tanaka
patent: 09 213078 (1997-08-01), None

Affiliated with

Also associated with

Rating

Sense amplifier does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Sense amplifier, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sense amplifier will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2866422