PLL with switched parameters
First Claim
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1. A phase-locked loop frequency synthesizer comprising:
- a phase-locked loop, including a charge pump and an integration filter, disposed to function in a first mode and in a second mode;
a mode detection circuit for generating a first detection signal to initiate transition of the phase-locked loop from the first mode to the second mode; and
a switching network for changing, at least in part in response to the first detection signal, the values of a first operating parameter and a second operating parameter of the phase-locked loop, said first operating parameter associated with the charge pump and said second operating parameter associated with the integration filter;
wherein a divider circuit comprises an N counter and the switching network switches the values of the operating parameters subsequent to generation of the first detection signal and upon the N counter registering a predefined count value.
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Abstract
A system and method of operating a phase-locked loop frequency synthesizer is disclosed herein. The disclosed method includes defining a first set of operating parameters applicable to operation of a phase-locked loop of the synthesizer in a first mode and defining a second set of operating parameters applicable to operation of the phase-locked loop in a second mode. A first detection signal is generated so as to initiate transition of the phase-locked loop into the second mode. The method further includes configuring, at least in part in response to the first detection signal, the phase-locked loop to operate in accordance with the second set of operating parameters.
115 Citations
33 Claims
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1. A phase-locked loop frequency synthesizer comprising:
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a phase-locked loop, including a charge pump and an integration filter, disposed to function in a first mode and in a second mode; a mode detection circuit for generating a first detection signal to initiate transition of the phase-locked loop from the first mode to the second mode; and a switching network for changing, at least in part in response to the first detection signal, the values of a first operating parameter and a second operating parameter of the phase-locked loop, said first operating parameter associated with the charge pump and said second operating parameter associated with the integration filter;
wherein a divider circuit comprises an N counter and the switching network switches the values of the operating parameters subsequent to generation of the first detection signal and upon the N counter registering a predefined count value. - View Dependent Claims (2, 3, 4, 5, 6, 8, 24, 25)
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7. A phase-locked loop frequency synthesizer comprising:
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a phase-locked loop disposed to function in a first mode and in a second mode, said phase locked loop including; a voltage-controlled oscillator for generating an output signal of a frequency determined by a control voltage; a divider circuit for dividing the output signal to produce a frequency-divided signal; a phase/frequency detector disposed to compare phases between an input reference signal and the frequency-divided signal and to produce a first phase error signal and a second phase error signal; a charge pump circuit for producing a charge pump signal in response to the first phase error signal and the second phase error signal; a loop filter which produces the control voltage in response to the charge pump signal; a mode detection circuit for generating a first detection signal to initiate transition of the phase-locked loop from the first mode to the second mode; and a switching network for changing, at least in part in response to the first detection signal values of one or more operating parameters of the phase-locked loop;
wherein the divider circuit comprises an N counter and the switching network switches the values of the operating parameters subsequent to generation of the first detection signal and upon the N counter registering a predefined count value.
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9. A method of operating a phase-locked loop frequency synthesizer, the method comprising:
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defining a first set of operating parameters applicable to operation of a phase-locked loop of the synthesizer in a first mode and a second set of operating parameters applicable to operation of the phase-locked loop in a second mode, said phase-locked loop having a charge pump and an integration filter and said first and said second set of operating parameters each including a first operating parameter associated with the charge pump and a second operating parameter associated with the integration filter; generating a first detection signal so as to initiate transition of the phase-locked loop into the second mode; and configuring, at least in part in response to the first detection signal, the phase-locked loop to operate in accordance with the second set of operating parameters, wherein said configuring includes switching the value of the second operating parameter of the second set of operating parameters;
wherein a divider circuit comprises an N counter and a switching network switches values of the operating parameters subsequent to generation of the first detection signal and upon the N counter registering a predefined count value. - View Dependent Claims (10, 11, 12, 13, 26, 27)
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14. A method of operating a phase-locked loop frequency synthesizer wherein the phase locked loop generates an output signal of a frequency determined by a control voltage, the method comprising:
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defining a first set of operating parameters applicable to operation of a phase-locked loop of the synthesizer in a first mode and a second set of operating parameters applicable to operation of the phase-locked loop in a second mode; generating a first detection signal so as to initiate transition of the phase-locked loop into the second mode; and configuring, at least in part in response to the first detection signal, the phase-locked loop to operate in accordance with the second set of operating parameters;
wherein the phase-locked loop;divides the output signal to produce a frequency-divided signal, the frequency divided signal being produced using an N counter; compares phases of an input reference signal and the frequency-divided signal and producing a first phase error signal and a second phase error signal; produces a charge pump signal in response to the first phase error signal and the second phase error signal; and generates the control voltage in response to the charge pump signal; and
wherein the phase-locked loop is configured to operate in accordance with the second set of operating parameters subsequent to generation of the first detection signal and upon the N counter registering a predefined count value.
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15. An apparatus for configuring operational parameters of a phase locked loop, comprising:
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a mode detection circuit for generating a first detection signal to transition the phase-locked loop from a first operative mode to a second operative mode; and a parameter switching network operative to switch, at least in part in response to the first detection signal, values of a first operating parameter associated with a charge pump and a second operating parameter associated with an integration filter of the phase-locked loop from a first state to a second state;
wherein a divider circuit comprises an N counter and the switching network switches the values of the operating parameters subsequent to generation of the first detection signal and upon the N counter registering a predefined count value. - View Dependent Claims (16, 17, 28, 29)
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18. A phase-locked loop module, comprising:
a voltage-controlled oscillator for generating an output signal of a frequency determined by a control voltage; a divider circuit for dividing the output signal to produce a frequency-divided signal; a phase/frequency detector disposed to compare phases between an input reference signal and the frequency-divided signal and to produce a first phase error signal and a second phase error signal; a charge pump circuit for producing a charge pump signal in response to the first phase error signal and the second phase error signal, the charge pump circuit characterized by a first operating parameter; a loop filter for producing the control voltage in response to the charge pump signal, the loop filter characterized by a second operating parameter; and a parameter switching arrangement for changing values of the first and second operating parameters subsequent to transition of the phase-locked loop from a first operative mode to a second operative mode;
wherein the divider circuit comprises an N counter and the switching arrangement switches the values of the operating parameters subsequent to generation of the first detection signal and upon the N counter registering a predefined count value.- View Dependent Claims (19, 20, 21, 30, 31)
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22. A phase-locked loop frequency synthesizer comprising:
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a phase-locked loop disposed to function in a first operative mode and in a second operative mode; a parameter switching arrangement for switching values of a first operating parameter of the phase-locked loop associated with a charge pump and a second operating parameter of the phase-locked loop associated with a loop filter of the phase-locked loop from a first state to a second state subsequent to transition of the phase-locked loop from the first operative mode into the second operative mode;
wherein a divider circuit comprises an N counter and the switching arrangement switches the values of the operating parameters subsequent to generation of the first detection signal and upon the N counter registering a predefined count value. - View Dependent Claims (23, 32, 33)
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Specification