EP0414392A2
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EP
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Phase detector
Assignee: Plessey Semiconductors Ltd
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Filing: 1990-08-01
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Granted: —
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Expires: 2010-08-01
Abstract
Abstract A phase detector comprising a first ramp generator (44) responsive to a reference oscillator (40) input signal for initiating a first ramp waveform, a second ramp generator (54) responsive to a variable frequency oscillator (50) signal input for initiating a second ramp waveform, the first and second ramp generators being coupled respectively to first (46) and second (56) sample and hold circuits, means responsive to the first ramp waveform to actuate the first and second sample and hold circuits, and comparison means (48) for comparing the signal values stored in the first and second hold circuits whereby to provide an output signal indicative of the phase difference between the reference oscillator and variable frequency oscillator input signals.
Inventors
- 👤 Ian Godfrey Fobbester
- 👤 David Stuart Clarke
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 18:21
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/085; H03L7/091; H03L7/087
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
110 words
A phase detector comprising a first ramp generator responsive to a reference oscillator input signal for initiating a first ramp waveform, a second ramp generator responsive to a variable frequency oscillator signal input for initiating a second ramp waveform, the first and second ramp generators being coupled respectively to first and second sample and hold circuits, means responsive to the first ramp waveform to actuate the first and second sample and hold circuits, and comparison means for comparing the signal values stored in the first and second hold circuits whereby to provide an output signal indicative of the phase difference between the reference oscillator and variable frequency oscillator input signals.
Claim 2
Dependent Claim
110 words
A phase detector comprising a first ramp generator responsive to a reference oscillator input signal for initiating a first ramp waveform, a second ramp generator responsive to a variable frequency oscillator signal input for initiating a second ramp waveform, the first and second ramp generators being coupled respectively to first and second sample and hold circuits, means responsive to the first ramp waveform to actuate the first and second sample and hold circuits, and comparison means for comparing the signal values stored in the first and second hold circuits whereby to provide an output signal indicative of the phase difference between the reference oscillator and variable frequency oscillator input signals.
Claim 3
Dependent Claim
36 words
A phase detector according to claim 1 wherein the actuating means for the sample and hold circuits comprise a sample pulse generator arranged to generate a sample pulse at the mid-point of the first ramp waveform.
Claim 4
Dependent Claim
26 words
A phase detector as claimed in claim 2 wherein said sample pulse generator is arranged to provide reset signals to said first and second ramp generators.
Claim 5
Dependent Claim
20 words
A phase detector according to claim 1 wherein the comparison means comprises a differential amplifier providing a current signal output.
Claim 6
Dependent Claim
45 words
A phase detector according to claim 3 in combination with a digital phase/frequency detector coupled to receive said reference oscillator input signal and said variable frequency oscillator input signal to provide a current signal output which is summed with the output of said differential amplifier.
Claim 7
Dependent Claim
44 words
A phase detector as claimed in claim 1 including a reference oscillator and a reference divider chain for providing said reference oscillator input signal, and a variable frequency oscillator and a variable frequency oscillator divider chain for providing said variable frequency oscillator input signal.
Claim 8
Dependent Claim
15 words
A phase detector as claimed in any preceding claim incorporated in a phase locked loop.
Claim 9
Dependent Claim
12 words
A phase detector substantially as described with reference to the accompanying drawings.
Claim 10
Dependent Claim
12 words
A phase detector substantially as described with reference to the accompanying drawings.
References Cited (Backward Citations)
No citation records indexed.
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