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US 7,120,217 B2Granted
Phase-locked loop circuit
AssigneeATMEL Germany GmbH
InventorMarco Schwarzmueller
Life of this patent
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Abstract
In a PLL circuit including a voltage-controlled oscillator, a phase detector and a final control element, the final control element contains two separate channels, between the phase detector and the voltage controlled oscillator, wherein one channel processes the useful signal components and the other channel processes the disturbance signal components of the synchronization pulses. Each channel has two tracks, for generation of a potential difference, wherein each track is connected to a capacitor plate.
Claims24
A phase-locked loop circuit comprising:
- a voltage-controlled oscillator that has plural voltage inputs including at least one first voltage input and at least one second voltage input, and an oscillation output;
- a phase detector that has an actual frequency input and plural control outputs including first and second control outputs, and that is adapted to detect a phase deviation of an actual frequency received at said actual frequency input relative to a reference frequency, and to produce first synchronization pulses having useful signal components and disturbance signal components at said first control output when said phase deviation is a lagging phase deviation, and to produce second synchronization pulses having useful signal components and disturbance signal components at said second control output when said phase deviation is a leading phase deviation;
- a feedback path connecting said oscillation output of said voltage-controlled oscillator to said actual frequency input of said phase detector;
- and
- a control arrangement interposed and connected between said control outputs of said phase detector and said voltage inputs of said voltage-controlled oscillator;
- wherein:
- said control arrangement includes a first channel and a second channel that connect said control outputs to said voltage inputs,
- said first channel includes respective control inputs respectively connected to said first control output and said second control output, a first charge pump arrangement, and a first loop filter arrangement including at least one first capacitor dimensioned and connected so as to produce a first control voltage signal dependent only on said useful signal components of respective ones of said first and second synchronization pulses,
- said first channel is connected to said at least one first voltage input of said voltage-controlled oscillator so as to provide said first control voltage signal to said at least one first voltage input,
- said second channel includes respective control inputs respectively connected to said first control output and said second control output, a second charge pump arrangement, and a second loop filter arrangement differing from said first loop filter arrangement and including at least one passive filter element dimensioned and connected so as to produce a second control voltage signal dependent only on said disturbance signal components of respective ones of said first and second synchronization pulses, and
- said second channel is connected to said at least one second voltage input of said voltage-controlled oscillator so as to provide said second control voltage signal to said at least one second voltage input.
8 more elements
A phase-looked loop circuit comprising:
- a voltage-controlled oscillator that has plural voltage inputs including at least one first voltage input and at least one second voltage input, and an oscillation output;
- a phase detector that has an actual frequency input and plural control outputs including first and second control outputs, and that is adapted to detect a phase deviation of an actual frequency received at said actual frequency input relative to a reference frequency, and to produce first synchronization pulses having useful signal components and disturbance signal components at said first control output when said phase deviation is a lagging phase deviation, and to produce second synchronization pulses having useful signal components and disturbance signal components at said second control output when said phase deviation is a leading phase deviation;
- a feedback path connecting said oscillation output of said voltage-controlled oscillator to said actual frequency input of said phase detector;
- and
- a control arrangement interposed and connected between said control outputs of said phase detector and said voltage inputs of said voltage-controlled oscillator;
- wherein:
- said control arrangement includes a first channel and a second channel;
- said first channel includes a first charge pump arrangement, first channel control inputs respectively connected to said first control output and said second control output of said phase detector, and a first loop filter arrangement including at least one first capacitor connected between said first charge pump arrangement and said at least one first voltage input of said voltage-controlled oscillator;
- said second channel includes a second charge pump arrangement, second channel control inputs respectively connected to said first control output and said second control output of said phase detector, and a second loop filter arrangement including at least one passive filter element connected between said second charge pump arrangement and said at least one second voltage input of said voltage-controlled oscillator;
- said first channel has first parameters including a first pump current that characterizes said first charge pump arrangement, a first filter characteristic that characterizes said first loop filter arrangement, and a first frequency-voltage gain characteristic that characterizes said at least one first voltage input of said voltage-controlled oscillator;
- said second channel has second parameters including a second pump current that characterizes said second charge pump arrangement, a second filter characteristic that characterizes said second loop filter arrangement, and a second frequency-voltage gain characteristic that characterizes said at least one second voltage input of said voltage-controlled oscillator;
- and
- at least one of said second parameters differs from a counterpart one of said first parameters so that a first control voltage signal provided to said at least one first voltage input of said voltage-controlled oscillator from said first channel is dependent predominantly on said useful signal components of said first and second synchronization pulses, and a second control voltage signal provided to said at least one second voltage input of said voltage-controlled oscillator from said second channel is dependent predominantly on said disturbance signal components of said first and second synchronization pulses.
10 more elements
Dependencies are inferred from the claim text.