Accession Number : ADD005937

Title :   Digital Phase-Frequency Detector.

Descriptive Note : Patent Application,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON D C

Personal Author(s) : Kimsey,T H

Report Date : 16 Feb 1979

Pagination or Media Count : 9

Abstract : A digital phase-frequency detector which provides rapid frequency acquisition and phase control when used in phase-locked loop applications. In a locked condition the output of a pair of flip-flop circuits are high causing an EXOR gate to produce a detector output, when unlocked a phase difference will increase until the higher frequency exhibits two positive transitions before one positive transition of the lower frequency can propagate through the circuit, this will cause the flip-flop receiving the higher frequency to change state thereby preventing the EXOR gate from gating and the other flip-flop from changing state, the flip-flop therefore controls the detector output until the two input frequencies again coincide and the output controlled by the EXOR gate. (Author)

Descriptors :   *Patent applications, *Phase detectors, *Phase locked systems, *Flip flop circuits, Digital systems, Frequency, Gates(Circuits), Output, Control systems, Oscillators, Signal processing

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE