Integrated circuit comprising a frequency dependent circuit, wireless device and method of adjusting a frequency
First Claim
1. An integrated circuit for a wireless device, the integrated circuit comprising a frequency dependent circuit comprising:
- an input node;
an output node;
a main bank of selectable first capacitive elements that affect a frequency characteristic of the frequency dependent circuit;
a first shunt bank of selectable second capacitive elements located between ground and the input node;
a second shunt bank of selectable second capacitive elements located between ground and the output node;
a phase locked loop comprising a phase frequency detector and a voltage controlled oscillator, an output of phase frequency detector coupled to an input of the voltage controlled oscillator, wherein the input node defines an input of the voltage controlled oscillator and the output node defines an output of the voltage controlled oscillator, and wherein the phase frequency detector is coupled to receive a reference frequency and is coupled to a divided frequency output of the voltage controlled oscillator with a switch; and
a controller configured to;
apply a tuning voltage to the phase frequency detector;
control the switch to open a loop of the phase locked loop; and
subsequent to opening the loop of the phase locked loop, selectively enable or disable at least one selectable second capacitive element as a function of a number of the selectable first capacitive elements that are switched into the frequency dependent circuit.
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Accused Products
Abstract
An integrated circuit comprises a frequency dependent circuit comprising an input node, an output node and a main bank of selectable first capacitive elements that affect a frequency characteristic of the frequency dependent circuit. The frequency dependent circuit further comprises at least one shunt bank of selectable second capacitive elements located between ground and one of the input node or the output node, wherein at least one selectable second capacitive element switched out of the frequency dependent circuit is based on a number of the selectable first capacitive elements that are switched into the frequency dependent circuit.
32 Citations
16 Claims
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1. An integrated circuit for a wireless device, the integrated circuit comprising a frequency dependent circuit comprising:
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an input node; an output node; a main bank of selectable first capacitive elements that affect a frequency characteristic of the frequency dependent circuit; a first shunt bank of selectable second capacitive elements located between ground and the input node; a second shunt bank of selectable second capacitive elements located between ground and the output node; a phase locked loop comprising a phase frequency detector and a voltage controlled oscillator, an output of phase frequency detector coupled to an input of the voltage controlled oscillator, wherein the input node defines an input of the voltage controlled oscillator and the output node defines an output of the voltage controlled oscillator, and wherein the phase frequency detector is coupled to receive a reference frequency and is coupled to a divided frequency output of the voltage controlled oscillator with a switch; and a controller configured to; apply a tuning voltage to the phase frequency detector; control the switch to open a loop of the phase locked loop; and subsequent to opening the loop of the phase locked loop, selectively enable or disable at least one selectable second capacitive element as a function of a number of the selectable first capacitive elements that are switched into the frequency dependent circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A wireless device, comprising a frequency dependent circuit comprising:
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an input node; an output node; a main bank of selectable first capacitive elements that affect a frequency characteristic of the frequency dependent circuit; a first shunt bank of selectable second capacitive elements located between ground and the input node; a second shunt bank of selectable second capacitive elements located between ground and the output node; a phase locked loop comprising a phase frequency detector and a voltage controlled oscillator, an output of phase frequency detector coupled to an input of the voltage controlled oscillator, wherein the input node defines an input of the voltage controlled oscillator and the output node defines an output of the voltage controlled oscillator, and wherein the phase frequency detector is coupled to receive a reference frequency and is coupled to a divided frequency output of the voltage controlled oscillator with a switch; and a controller configured to; apply a tuning voltage to the phase frequency detector; control the switch to open a loop of the phase locked loop; and subsequent to opening the loop of the phase locked loop, selectively enable or disable at least one selectable second capacitive element as a function of a number of the selectable first capacitive elements that are switched into the frequency dependent circuit.
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Specification