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US 7,095,286 B2Granted
PLL circuit, communication apparatus equipped with PLL circuit, and frequency adjustment method
AssigneeFujitsu Media Devices Limited
InventorYasushi Fukuda
Life of this patent
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Abstract
A PLL circuit includes a voltage-controlled oscillator having a control voltage terminal, a charge pump, a loop filter having an output coupled with the control voltage terminal via the loop filter, and a part for connecting any point on a route from an output terminal of the charge pump to the control voltage terminal to ground and disconnecting said point from the ground after a frequency of the voltage-controlled oscillator is adjusted.
Claims11
A PLL circuit comprising:
- a voltage-controlled oscillator having a control voltage terminal and an adjusting means for adjusting a frequency of the voltage-controlled oscillator;
- a charge pump;
- a loop filter having an output coupled with the control voltage terminal via the loop filter;
- and
- a shorting member that initially connects ground to a conductor connecting an output terminal of the charge pump to the control voltage terminal and permanently disconnects the conductor from the ground after the frequency of the voltage-controlled oscillator is adjusted.
2 more elements
A PLL circuit comprising:
- a voltage-controlled oscillator having a control voltage terminal and an adjusting means for adjusting a frequency of the voltage-controlled oscillator;
- a charge pump;
- a loop filter having an output coupled with the control voltage terminal via the loop filter;
- and
- shorting means for connecting ground to a conductor connecting an output terminal of the charge pump to the control voltage terminal and disconnecting said conductor from the ground after the frequency of the voltage-controlled oscilator is adjusted,
- wherein said means comprises a wiring electrode that is cut after the frequency of the voltage-controlled oscillator is adjusted.
3 more elements
A PLL circuit comprising:
- a voltage-controlled oscillator having a control voltage terminal and an adjusting means for adjusting a frequency of the voltage-controlled oscillator;
- a charge pump;
- a loop filter having an output coupled with the control voltage terminal via the loop filter;
- and
- shorting means for connecting ground to a conductor connecting an output terminal of the charge pump to the control voltage terminal and disconnecting said conductor from the ground after the frequency of the voltage-controlled oscillator is adjusted,
- wherein said means comprises a jumper chip.
3 more elements
A PLL circuit comprising:
- a voltage-controlled oscillator having a control voltage terminal and an adjusting means for adjusting a frequency of the voltage-controlled oscillator;
- a charge pump;
- a loop filter having an output coupled with the control voltage terminal via the loop filter;
- and
- shorting means for connecting ground to a conductor connecting an output terminal of the charge pump to the control voltage terminal and disconnecting said conductor from the ground after the frequency of the voltage-controlled oscillator is adjusted,
- wherein said means comprises one of a jumper wire and a jumper pin.
3 more elements
A PLL circuit comprising:
- a voltage-controlled oscillator having a control voltage terminal and an adjusting means for adjusting a frequency of the voltage-controlled oscillator;
- a charge pump;
- a loop filter having an output coupled with the control voltage terminal via the loop filter;
- and
- shorting means for connecting ground to a conductor connecting an output terminal of the charge pump to the control voltage terminal and disconnecting said conductor from the ground after the frequency of the voltage-controlled oscillator is adjusted,
- wherein said means comprises solder.
3 more elements
A PLL circuit comprising:
- a voltage-controlled oscillator having a control voltage terminal and an adjusting means for adjusting a frequency of the voltage-controlled oscillator;
- a charge pump;
- a loop filter having an output coupled with the control voltage terminal via the loop filter;
- shorting means for connecting ground to a conductor connecting an output terminal of the charge pump to the control voltage terminal and disconnecting said conductor from the ground after the frequency of the voltage-controlled oscillator is adjusted, and
- a phase comparator and a frequency divider,
- wherein a power supply line provided for the circuit composed of the charge pump, the phase comparator and the frequency divider is separate from a power supply line provided for the voltage-controlled oscillator.
3 more elements
A communication apparatus comprising:
- a mixer mixing a first signal with a second signal;
- and
- a PLL synthesizer generating the second signal,
- the PLY synthesizer comprising:
- a voltage-controlled oscillator generating the second signal and having control voltage terminal and an adjusting means for adjusting a frequency of the voltage-controlled oscillator;
- a charge pump;
- a loop filter having an output coupled with the control voltage terminal via the loop filter;
- and
- a shorting member that initially connects ground to a conductor connecting an output terminal of the charge pump to the control voltage terminal and permanently disconnects said conductor from the ground after the frequency of the voltage-controlled oscillator is adjusted.
6 more elements
A method of adjusting a frequency of a PLL circuit in which an output terminal of a charge pump is coupled with a control voltage terminal of a voltage-controlled oscillator via a loop filter, comprising the steps of;
- connecting ground to a conductor connecting the output terminal of the charge pump to the control voltage terminal with a shorting member;
- and
- disconnecting said conductor from the ground, after a frequency of the voltage-controlled oscillator is adjusted, by cutting the member.
Dependencies are inferred from the claim text.