Adaptive threshold logic circuit

Details Adaptive threshold logic circuit Adaptive threshold logic circuit

2001-03-14

2002-12-24

Lee, Michael G. (Department: 2876)

Electronic digital logic circuitry

Interface

Supply voltage level shifting

C326S036000, C326S062000, C326S063000, C326S068000

Reexamination Certificate

active

06498510

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a logic circuit which is capable of adjusting a switching threshold in accordance with the voltage level of applied input logic signals.
BACKGROUND OF THE INVENTION
Digital logic circuits are sometimes arranged such that a first logic circuit operates with one supply voltage, e.g., 3.3 volts, while another circuit supplying input logic signals to the first logic circuit operates with a different supply voltage, e.g., 1.8 volts. In such a case, the logic signals supplied to the first logic circuit are incompatible with the switching threshold of the first logic circuit, which is set for applied input signals of 3.3 volts, causing erroneous and undesired switching operations.
A simple way of adjusting a switching threshold of a logic circuit to handle input logic signals of different voltage levels is needed.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a simple way of adjusting the switching threshold of a logic circuit in accordance with the signal level of input logic signals which are applied to it.
The invention provides a logic circuit with a voltage level detector stage which detects the supply voltage of a circuit supplying applied input signals, and an adaptive threshold stage which, in response to the output of the detector stage, selects a switching threshold level for switching operations in response to the applied logic input signals.
The adaptive threshold stage may be formed as a CMOS inverter circuit in which certain transistors are turned on or off in response to the output of the detector stage to thereby alter the inverter switching threshold.
These and other features and advantages of the invention will be more clearly seen from the following description of the invention which is provided in conjunction with the accompanying drawings.


REFERENCES:
patent: 4506168 (1985-03-01), Uya
patent: 4539489 (1985-09-01), Vaughn
patent: 4603264 (1986-07-01), Nakano
patent: 5240196 (1993-08-01), Baarfuesser
patent: 5444392 (1995-08-01), Sommer et al.
patent: 5654664 (1997-08-01), Park et al.
patent: 5751166 (1998-05-01), Shieh et al.
patent: 5856750 (1999-01-01), Koseki
patent: 5886556 (1999-03-01), Ganger et al.
patent: 6118348 (2000-09-01), Narahara
patent: 6181172 (2001-01-01), Callahan
patent: 409064700 (1997-03-01), None

Affiliated with

Also associated with

Rating

Adaptive threshold logic circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.

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

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2972816