Charge pump circuit using active feedback controlled current sources
First Claim
1. A charge pump circuit comprising:
- a sinking current source for driving current out of an output node of the charge pump circuit;
a sourcing current source for driving current into the output node;
a switching section for selectively connecting the sinking and sourcing current sources to the output node in response to control signals;
a first active feedback control circuit controlling a current produced by the sinking current source; and
a second active feedback control circuit controlling a current produced by the sourcing current source.
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Accused Products
Abstract
A charge pump circuit utilizes active feedback control circuits to control the currents produced by sinking and sourcing current sources. The feedback control circuits may regulate the drain voltages of sinking and sourcing current source transistors to make them approximately equal to respective reference voltages received by the feedback control circuits. The charge pump circuit may utilize multiple supply voltages, with a higher supply voltage such as a 3.3 V supply voltage being used to drive current source transistors, and a lower supply voltage such as a 1.8 V supply voltage being used to drive switches in a switching section.
37 Citations
23 Claims
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1. A charge pump circuit comprising:
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a sinking current source for driving current out of an output node of the charge pump circuit;
a sourcing current source for driving current into the output node;
a switching section for selectively connecting the sinking and sourcing current sources to the output node in response to control signals;
a first active feedback control circuit controlling a current produced by the sinking current source; and
a second active feedback control circuit controlling a current produced by the sourcing current source. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A phase locked loop circuit, comprising:
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a phase frequency detector receiving as inputs an input frequency and an output frequency, and generating control signals in response to the input frequency and the output frequency;
a charge pump circuit receiving control signals from the phase frequency detector, and having an output node coupled to a low pass filter and to an input of a voltage controlled oscillator; and
a frequency divider receiving an input signal from the voltage controlled oscillator and producing said output frequency at its output, wherein the charge pump circuit comprises;
a sinking current source for driving current out of an output node of the charge pump circuit;
a sourcing current source for driving current into the output node;
a switching section for selectively connecting the sinking and sourcing current sources to the output node in response to control signals;
a first active feedback control circuit controlling a current produced by the sinking current source; and
a second active feedback control circuit controlling a current produced by the sourcing current source. - View Dependent Claims (11, 12, 13, 14)
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15. A transceiver circuit for a wireless communication device, the transceiver circuit including a phase locked loop circuit, the phase locked loop circuit comprising:
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a phase frequency detector receiving as inputs an input frequency and an output frequency, and generating control signals in response to the input frequency and the output frequency;
a charge pump circuit receiving control signals from the phase frequency detector, and having an output node coupled to a low pass filter and to an input of a voltage controlled oscillator; and
a frequency divider receiving an input signal from the voltage controlled oscillator and producing said output frequency at its output, wherein the charge pump circuit comprises;
a sinking current source for driving current out of an output node of the charge pump circuit;
a sourcing current source for driving current into the output node;
a switching section for selectively connecting the sinking and sourcing current sources to the output node in response to control signals;
a first active feedback control circuit controlling a current produced by the sinking current source; and
a second active feedback control circuit controlling a current produced by the sourcing current source. - View Dependent Claims (16, 17, 18, 19)
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20. A method for operating a charge pump circuit, comprising:
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receiving a first reference voltage at an input of a first active feedback control device associated with a sinking transistor of the charge pump circuit;
regulating the drain voltage of the sinking transistor by the first active feedback control device such that the drain voltage is approximately equal to the first reference voltage;
receiving a second reference voltage at an input of a second active feedback control device associated with a sourcing transistor of the charge pump circuit;
regulating the drain voltage of the sourcing transistor by the second active feedback control device such that the drain voltage is approximately equal to the second reference voltage; and
selectively coupling the sinking transistor and the sourcing transistor to an output node of the charge pump circuit in response to control signals received by the charge pump circuit. - View Dependent Claims (21, 22)
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23. A method for operating a charge pump circuit, comprising:
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receiving a reference current;
controlling the current of a sinking current source by active feedback control to be approximately equal to the reference current;
controlling the current of a sourcing current source by active feedback control to be approximately equal to the reference current; and
selectively coupling the sinking current source and the sourcing current source to an output node of the charge pump circuit in response to control signals received by the charge pump circuit.
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Specification