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US 6,188,289 B1Granted
Wide range voltage controlled oscillator employing two current units
AssigneeSamsung Electronics Co., Ltd.
InventorYun-jong Hyeon
Life of this patent
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Abstract
A wide range voltage controlled oscillator including a voltage-to-current conversion unit generating a control current responsive to a control voltage, and an offset current generation unit generating an offset current. The offset current generation unit is responsive to the control voltage and, at certain times, is responsive to a reference voltage. An adding unit adds the control current to the offset current, and generates an oscillation control current. An oscillation unit generates the oscillation signal responsive to the oscillation control current.
Claims20
A voltage controlled oscillator that generates an oscillation signal in response to a control voltage, the voltage controlled oscillator comprising:
- a voltage-to-current conversion unit for converting the control voltage into a control current;
- a switch that selects either the control voltage or a first reference voltage and generates a selected voltage;
- a generator that generates a first signal responsive to the selected voltage, and an offset current responsive to the selected voltage;
- an adding unit for adding the control current to the offset current and generating an oscillation control current;
- and
- an oscillation unit for generating the oscillation signal having a frequency varying with the oscillation control current,
- wherein the switch is controlled by the first signal.
4 more elements
A voltage controlled oscillator that generates an oscillation signal in response to a control voltage, the voltage controlled oscillator comprising:
- a voltage-to-current conversion unit for converting the control voltage into a control current;
- an offset current generation unit for generating an offset current varying in response to changes in the control voltage;
- an adding unit for adding the control current to the offset current and generating an oscillation control current;
- and
- an oscillation unit for generating the oscillation signal having a frequency varying with the oscillation control current, wherein the offset current generation unit is responsive to a first reference voltage when the control voltage is greater than a first predetermined value for a first predetermined time and when the control voltage is less than a second predetermined value for a second predetermined time.
2 more elements
A voltage controlled oscillator that generates an oscillation signal in response to a control voltage, the voltage controlled oscillator comprising:
- a voltage-to-current conversion unit for converting the control voltage into a control current;
- an offset current generation unit for generating an offset current varying in response to changes in the control voltage;
- an adding unit for adding the control current to the offset current and generating an oscillation control current;
- and
- an oscillation unit for generating the oscillation signal having a frequency varying with the oscillation control current, wherein the offset current generation unit comprises:
- a switch for selecting either the control voltage or a first reference voltage and generating a selected voltage;
- a first comparator for comparing the selected voltage and a second reference voltage to generate a first compare signal;
- a second comparator for comparing the selected voltage and a third reference voltage to generate a second compare signal;
- a counter for receiving the first and second compare signals, the counter increasing its count in response to the first compare signal and decreasing its count in response to the second compare signal;
- and
- an offset current source for generating a current varying in response to the count of the counter, and generating the current as the offset current.
8 more elements
A voltage controlled oscillator that generates an oscillation signal, the voltage controlled oscillator comprising:
- a switch that selects either a control voltage or a first reference voltage and generates a selected voltage;
- a generator that generates a first signal responsive to the selected voltage, and an offset current varying in increments responsive to the selected voltage, and a first signal responsive to the selected voltage;
- an adding unit for adding the offset current to another current and generating an oscillation control current;
- and
- an oscillation unit for generating the oscillation signal having a frequency varying with the oscillation control current,
- wherein the switch is controlled by the first signal.
3 more elements
A phase locked loop comprising:
- a phase detector for detecting a phase difference between an input reference signal and an oscillation signal, and generating a phase difference signal;
- a filter for filtering the phase difference signal and generating a control voltage;
- and
- a voltage controlled oscillator for generating an oscillation signal whose frequency varies with the control voltage, the voltage controlled oscillator comprising:
- a voltage-to-current conversion unit for converting the control voltage into a control current;
- a switch that selects either the control voltage or a first reference voltage and generates a selected voltage;
- a generator that generates a first signal responsive to the selected voltage, and an offset current responsive to the selected voltage;
- an adding unit for adding the control current to the offset current and generating an oscillation control current;
- and
- an oscillation unit for generating the oscillation signal having a frequency varying with the oscillation control currents wherein the switch is controlled by the first signal.
7 more elements
A phase locked loop comprising:
- a phase detector for detecting a phase difference between an input reference signal and an oscillation signal, and generating a phase difference signal;
- a filter for filtering the phase difference signal and generating a control voltage;
- and
- a voltage controlled oscillator for generating an oscillation signal whose frequency varies with the control voltage, the voltage controlled oscillator comprising:
- a voltage-to-current conversion unit for converting the control voltage into a control current;
- an offset current generation unit for generating an offset current varying in response to changes in the control voltage;
- an adding unit for adding the control current to the offset current and generating an oscillation control current;
- and
- an oscillation unit for generating the oscillation signal having a frequency varying with the oscillation control current, wherein the offset current generation unit is responsive to a first reference voltage when the control voltage is greater than a first predetermined value for a first predetermined time and when the control voltage is less than a second predetermined value for a second predetermined time.
6 more elements
A phase locked loop comprising:
- a phase detector for detecting a phase difference between an input reference s and an oscillation signal, and generating a phase difference signal;
- a filter for filtering the phase difference signal and generating a control voltage;
- and
- a voltage controlled oscillator for generating an oscillation signal whose frequency varies with the control voltage, the voltage controlled oscillator comprising:
- a voltage-to-current conversion unit for converting the control voltage into a control current;
- an offset current generation unit for generating an offset current varying in response to changes in the control voltage;
- an adding unit for adding the control current to the offset current and generating an oscillation control current;
- and
- an oscillation unit for generating the oscillation signal having a frequency varying with the oscillation control current, wherein the offset current generation unit comprises:
- a switch for selecting either the control voltage or a first reference voltage and generating a selected voltage;
- a first comparator for comparing the selected voltage and a second reference voltage to generate a first compare signal;
- a second comparator for comparing the selected voltage and a third reference voltage to generate a second compare signal;
- a counter for receiving the first and second compare signals, the counter increasing its count in response to the first compare signal and decreasing its count in response to the second compare signal;
- and
- an offset current source for generating a current varying in response to the count of the counter, and generating the current as the offset current.
12 more elements
A method for generating a oscillation signal having a frequency varying in accordance with a control voltage, comprising:
- converting the control voltage into a control current;
- selecting either the control voltage or a first reference voltage and generating a selected voltage;
- generating a first signal responsive to the selected voltage, and an offset current responsive to the selected voltage;
- adding the control current to the offset current to generate an oscillation control current;
- and
- generating the oscillation signal whose frequency varies according to the oscillation control current,
- wherein the selecting is responsive to the first signal.
4 more elements
Dependencies are inferred from the claim text.