DIGITALLY CONTROLLED OSCILLATOR AND PHASE LOCKED LOOP CIRCUIT USING THE DIGITALLY CONTROLLED OSCILLATOR
First Claim
1. A digitally controlled oscillator comprising:
- a differential inductor including a positive terminal which outputs a positive-phase oscillation signal, a negative terminal which outputs a negative-phase oscillation signal, and a center tap, and including a first contact point in an arbitrary position between the positive terminal and the center tap, and a second contact point in a position corresponding to the first contact point between the negative terminal and the center tap;
a first variable capacitor bank connected between the positive terminal and the negative terminal and including a plurality of first variable capacitors which switch capacitance between two values by means of a first digital control code;
a second variable capacitor bank connected between the first contact point and the second contact point and including a plurality of second variable capacitors which switch capacitance between two values by means of a second digital control code; and
a negative resistor connected between the positive terminal and the negative terminal.
1 Assignment
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Accused Products
Abstract
A digitally controlled oscillator includes a differential inductor including a positive terminal which outputs a positive-phase oscillation signal, a negative terminal which outputs a negative-phase oscillation signal, and a center tap, and including a first contact point in an arbitrary position between the positive terminal and the center tap, and a second contact point in a position corresponding to the first contact point between the negative terminal and the center tap, a first variable capacitor bank connected between the positive terminal and the negative terminal and including a plurality of first variable capacitors which switch capacitance between two values according to a first digital control code, and a second variable capacitor bank connected between the first contact point and the second contact point and including a plurality of second variable capacitors which switch capacitance between two values according to a second digital control code.
39 Citations
10 Claims
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1. A digitally controlled oscillator comprising:
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a differential inductor including a positive terminal which outputs a positive-phase oscillation signal, a negative terminal which outputs a negative-phase oscillation signal, and a center tap, and including a first contact point in an arbitrary position between the positive terminal and the center tap, and a second contact point in a position corresponding to the first contact point between the negative terminal and the center tap; a first variable capacitor bank connected between the positive terminal and the negative terminal and including a plurality of first variable capacitors which switch capacitance between two values by means of a first digital control code; a second variable capacitor bank connected between the first contact point and the second contact point and including a plurality of second variable capacitors which switch capacitance between two values by means of a second digital control code; and a negative resistor connected between the positive terminal and the negative terminal. - View Dependent Claims (2, 3, 4, 10)
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5. A digitally controlled oscillator comprising:
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an inductor pair formed by shorting one end of a first inductor and one end of a second inductor, configured to output a positive-phase oscillation signal from the other end of the first inductor and output a negative-phase oscillation signal from the other end of the second inductor, and including a first contact point in an arbitrary position of the first inductor and a second contact point in a position corresponding to the first contact point of the second inductor; a first variable capacitor bank connected between the other end of the first inductor and the other end of the second inductor and including a plurality of first variable capacitors which switch capacitance between two values by a first digital control code; a second variable capacitor bank connected between the first contact point and the second contact point and including a plurality of second variable capacitors which switch capacitance between two values by a second control code; and a negative resistor connected between the other end of the first inductor and the other end of the second inductor. - View Dependent Claims (6, 7, 8, 9)
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Specification