US 5,084,669 A · Direct phase digitization

Abstract

An electrical circuit for producing a digital value which is representative of instantaneous phase of an electrical input signal relative to a reference frequency signal. The circuit includes a digital counter for continuously generating a stored count representing a value resulting from dividing the reference frequency signal by a repeating count cycle frequency which is of the same order as an expected center frequency of the electrical input signal. A trigger unit produces a trigger pulse in response to the trigger unit receiving a sampling pulse and a transition edge of the electrical input signal. An intermediate register stores a momentary state of the counter circuit in response to receiving the trigger pulse. The momentary state of the counter circuit corresponds to an instantaneous phase value of the electrical input signal. A correcting circuit is provided for correcting a resulting numerical value in the intermediate register by removing an accumulating phase offset value. An output register is provided for storing the corrected resulting numerical value of the counter circuit.

Claims41

Dependent claims

An electrical circuit for determining at specified sampling instants a numerical value which represents as a digital code an instantaneous phase of an electrical signal relative to a reference frequency signal, said circuit comprising:

counter means for continuously generating a stored count representing a value resulting from dividing said reference frequency signal by a repeating count cycle frequency, said count cycle repetition frequency being of the same order as an expected center frequency of said electrical signal;
trigger means for producing a trigger pulse in response to receiving a sampling pulse and a transition of said electrical signal;
and
first register means for storing a momentary state of said counter means, said momentary state of said counter means being transferred to said first register means in response to said first register means receiving said trigger pulse, said momentary state corresponding to an instantaneous phase value of said electrical signal.

1 more element

An electrical circuit for producing a digital value which is representative of an instantaneous phase of an input signal relative to a reference frequency, said circuit comprising:

a digital counter which continuously generates a stored count representing a value resulting from dividing said reference frequency by a repeating count cycle frequency;
a trigger circuit which produces a trigger pulse in response to being armed by a sampling pulse and being fired by a zero-crossing transition of said input signal;
and
a first storage latch for storing said value generated by said digital counter in response to receiving said trigger pulse, said stored value corresponding to an instantaneous phase value of said input signal.

1 more element

Dependencies are inferred from the claim text.

Direct phase digitization

Life of this patent

Direct phase digitization

Life of this patent

Abstract

Claims41