US 4,749,879 A · Signal transition detection method and system

Abstract

A system and method are provided for determining the occurrence of transitions in a binary encoded analog input signal. The system includes a threshold circuit, responsive to the input signal, for generating first and second grating signals in dependence upon whether the input signal exceeds or is less than a first threshold level, respectively. A first circuit means, responsive to the input signal, differentiates the input signal to form a first derivative signal. A threshold circuit, responsive to the first derivative signal, generates third and fourth gating signals in dependence upon whether the first derivative signal exceeds a second threshold level or is less than a third threshold level, respectively. A second circuit means, responsive to the first derivative signal, differentiates the first derivative signal to form a second derivative signal. The second derivative signal has zero crossings which are detected by a zero crossing means, responsive to the second derivative signal and to the first, second, third and fourth gating signals.

Claims20

Dependent claims

A method for determining the occurrence of transitions in a binary encoded analog input signal, comprising the steps of:

generating first and second gating signals in dependence upon whether said input signal exceeds or is less than a first threshold level, respectively,
differentiating said input signal to form a first derivative signal,
generating third and fourth gating signals in dependence upon whether said first derivative signal exceeds a second threshold level or is less than a third threshold level, respectively,
differentiating said first derivative signal to form a second derivative signal, said second derivative signal having zero crossings, and
detecting said zero crossings during the simultaneous generation of said first and third gating signals and during the simultaneous generation of said second and fourth gating signals, thereby determining transitions in said input signal.

2 more elements

A system for determining the occurrence of transitions in a binary encoded analog input signal, comprising:

first threshold means, responsive to said input signal, for generating first and second gating signals in dependence upon whether said input signal exceeds or is less than a first threshold level, respectively,
first circuit means, responsive to said input signal, for differentiating said input signal to form a first derivative signal,
second threshold means, responsive to said first derivative signal, for generating third and fourth gating signals in dependence upon whether said first derivative signal exceeds a second threshold level or is less than a third threshold level, respectively,
second circuit means, responsive to said first derivative signal, for differentiating said first derivative signal to form a second derivative signal, said second derivative signal having zero crossings, and
zero crossing means, responsive to said second derivative signal and to said first, second, third and fourth gating signals, for detecting said zero crossings of said second derivative signal during the simultaneous receipt of said first and third gating signals and during the simultaneous receipt of said second and fourth gating signals, thereby determining transitions in said input signal.

2 more elements

Dependencies are inferred from the claim text.

Signal transition detection method and system

Life of this patent

Signal transition detection method and system

Life of this patent

Abstract

Claims20