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US 7,030,705 B2Granted
Section selection loop filter and phase locked loop circuit having the same
AssigneeSamsung Electronics Co., Ltd.
InventorJae-Wan Kim
Life of this patent
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Abstract
A section selection loop filter for use in a phase lock loop for reducing sizes of hardware and increase ranges of tuning, including a selection signal outputting part for setting a first to fourth sections according to an input tuning voltage, selecting a first to fourth selection signals corresponding to the first to fourth sensing sections respectively, and outputting the first to fourth selection signals to a filtering part, and a filtering part for receiving and filtering a charge-pumping signal from a charge pump based on the four selection signals for the four sensing sections.
Claims23
A section selection loon filter, comprising:
- selection signal outputting part for setting a plurality of sensing sections according to an input tuning voltage, selecting a plurality of selection signals corresponding to the plurality of sensing sections respectively, and outputting the plurality of selection signals to a filtering part thereof;
- the filtering part for receiving and filtering a charge-pumping signal from a charge pump based on the plurality of selection signals;
- wherein the plurality of sensing sections include first to fourth sensing sections and the plurality of selection signals include first to fourth selection signals corresponding to the first to fourth sensing sections respectively.
A section selection loon filter, comprising:
- a selection signal outputting part for setting a plurality of sensing sections according to an input tuning voltage, selecting a plurality of selection signals corresponding to the plurality of sensing sections respectively, and outputting the plurality of selection signals to a filtering part thereof;
- the filtering part for receiving and filtering a charge-pumping signal from a charge pump based on the plurality of selection signals;
- wherein the outputting part includes an SR flip flop.
A phase locked loop circuit comprising:
- a voltage controlled oscillator for outputting a local frequency signal corresponding to a tuning voltage inputted from a loop filter thereof;
- a phase detector for comparing a reference signal with the local frequency signal outputted from a frequency divider connected to the voltage controlled oscillator, generating a pulse signal corresponding to the difference between the local frequency signal and the reference signal in view of phase, and outputting the pulse signal to a charge pump;
- a loop filter selector for setting a plurality of sensing sections according to the tuning voltage inputted from the loop filter, selecting a plurality of selection signals corresponding to the plurality of sensing sections respectively, and outputting the plurality of selection signals to the loop filter;
- and
- the loop filter for receiving and filtering the charge-pumping signals from the charge pump and outputting a plurality of tuning signals corresponding to the plurality of selection signals using the pulse signal to the voltage controlled oscillator;
- wherein the plurality of sensing sections include first to fourth sensing sections, the plurality of selection signals include first to fourth selection signals corresponding to the first to fourth sensing sections respectively, and the plurality of tuning signals includes a first to fourth tuning signals.
3 more elements
A phase locked loop circuit comprising:
- a voltage controlled oscillator for outputting a local frequency signal corresponding to a tuning voltage inputted from a loop filter thereof;
- a phase detector for comparing a reference signal with the local frequency signal outputted from a frequency divider connected to the voltage controlled oscillator, generating a pulse signal corresponding to the difference between the local frequency signal and the reference signal in view of phase, and outputting the pulse signal to a charge pump;
- a loop filter selector for setting a plurality of sensing sections according to the tuning voltage inputted from the loop filter, selecting a plurality of selection signals corresponding to the plurality of sensing sections respectively, and outputting the plurality of selection signals to the loop filter;
- and
- the loop filter for receiving and filtering the charge-pumping signals from the charge pump and outputting a plurality of tuning signals corresponding to the plurality of selection signals using the pulse signal to the voltage controlled oscillator;
- further comprising a lock stabilizing part for preventing the frequency signal from synchronizing with the reference signal when the tuning voltage is near one of a first transition point voltage and a second transition voltage.
3 more elements
An output full swing type low pass filter comprising:
- a resistor coupled between an input terminal and an output terminal;
- a PMOS capacitor coupled between a first electric source voltage and the output terminal;
- an NMOS capacitor coupled between a second electric source voltage and the output terminal;
- a first switching means coupled to the PMOS capacitor;
- a second switching means coupled to the NMOS capacitor;
- and
- a selection means for turning-on the second switching means in a first sensing section and turning-on the first switching means in a second sensing section, thereby coupling selectively the PMOS capacitor and the NMOS capacitor, wherein a voltage of the output terminal corresponding to the first sensing section is in the range of the second electric source voltage to a first transition point voltage and the voltage of the output terminal corresponding to the second sensing section is in the range of the first electric source voltage to a second transition point voltage.
4 more elements
Dependencies are inferred from the claim text.