Miscellaneous active electrical nonlinear devices – circuits – and – Signal converting – shaping – or generating – Current driver
Reexamination Certificate
2001-09-26
2003-09-09
Callahan, Timothy P. (Department: 2816)
Miscellaneous active electrical nonlinear devices, circuits, and
Signal converting, shaping, or generating
Current driver
C327S112000
Reexamination Certificate
active
06617891
ABSTRACT:
BACKGROUND
1. Field of the Invention
This invention relates to buffers. In particular, the invention relates to slew rate control.
2. Description of Related Art
Output buffers in high-speed circuits such as double data rate (DDR) memory and front side bus (FSB) interfaces are important in maintaining data integrity. The signals that are transmitted from the buffer to the external devices outside the device package should have sufficient drive strength and satisfactory slew rate. Slew rate is the rate of change of the signal amplitude. It is typically expressed as the change in voltage with respect to time.
Output pads for a device are subject to ground bounce noise phenomenon. This phenomenon is typically caused by the switching of voltage from one logic level to another. When several outputs change state simultaneously, the combined current variations at these outputs generate noise on power rails which has a significant affect on the rate of change of the signal amplitude. Slew rate control becomes important when there are many outputs switching at the same time, or when the data rate is high.
Therefore, there is a need to have an efficient technique to improve slew rate performance.
REFERENCES:
patent: 4559507 (1985-12-01), Ramsdale et al.
patent: 4972436 (1990-11-01), Halim et al.
patent: 5734285 (1998-03-01), Harvey
patent: 5959492 (1999-09-01), Khoury et al.
patent: 5963057 (1999-10-01), Schmitt et al.
patent: 6285214 (2001-09-01), Zipper
Dour Navneet
Srikanth Adhiveeraraghavan
Callahan Timothy P.
Nguyen Linh
LandOfFree
Slew rate at buffers by isolating predriver from driver does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Slew rate at buffers by isolating predriver from driver, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Slew rate at buffers by isolating predriver from driver will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3002178