Differential charge pump with common mode control
First Claim
1. Charge pump for providing an output current for charging and discharging a filter in accordance with an input signal, said charge pump comprising:
- a first current source coupled to the input signal for driving the first current source and configured to provide a first current, the first current being generated by adding a variable current (Δ
x) to a constant current (Io) and the variable current (Δ
x) being directly proportional to the input signal;
a second current source coupled to the input signal for driving the second current source and configured to provide a second current, the second current being generated by subtracting the variable current (Δ
x) from the constant current (Io); and
an output configured to provide the output current, wherein said output is coupled to both the first and second current source in such a way that the output current is equal to a difference between the first and second current.
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Accused Products
Abstract
Charge pump for providing an output current for charging and discharging a filter in accordance with an input signal, said charge pump comprising a first current source connectable with the input signal for driving the current source and adapted to providing a first current equal to a constant current Io plus a variable current Δx, said variable current Δx being directly proportional to the input signal, a second current source connectable with the input signal for driving the current source and adapted to providing a second current equal to the constant current Io minus said variable current Δx, and an output for providing the output current, wherein said output is connected to both the first and second current source in such a way, that the output current is equal to a difference between the first and second current.
13 Citations
10 Claims
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1. Charge pump for providing an output current for charging and discharging a filter in accordance with an input signal, said charge pump comprising:
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a first current source coupled to the input signal for driving the first current source and configured to provide a first current, the first current being generated by adding a variable current (Δ
x) to a constant current (Io) and the variable current (Δ
x) being directly proportional to the input signal;a second current source coupled to the input signal for driving the second current source and configured to provide a second current, the second current being generated by subtracting the variable current (Δ
x) from the constant current (Io); andan output configured to provide the output current, wherein said output is coupled to both the first and second current source in such a way that the output current is equal to a difference between the first and second current. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A charge pump for providing an output current for charging and discharging a filter in accordance with an input signal, said charge pump comprising:
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a first current source coupled to the input signal for driving the first current source and configured to provide a first current, the first current being generated by adding a variable current (Δ
x) to a constant current (Io);a second current source coupled to the input signal for driving the second current source and configured to provide a second current, the second current being generated by subtracting the variable current (Δ
x) from the constant current (Io); andan output configured to provide the output current, wherein said output is coupled to both the first and second current source in such a way that the output current is equal to a difference between the first and second current, wherein the output comprises a first output terminal and a second output terminal, each output terminal being connected to both the first and second current source; and wherein the input signal is an output signal of a one of a phase detector and a frequency detector, and the variable current (Δ
x) of the first and second current sources is directly proportional to the input signal.
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Specification