Switched capacitor circuit of a pipeline analog to digital converter and a method for operating the switched capacitor circuit
First Claim
1. A switched capacitor circuit comprising:
- an operational amplifier having a first input terminal and a first output terminal;
a first sampling capacitor having a first terminal and a second terminal, the first terminal being connected to the first input terminal of the operational amplifier;
a first signal input switch controlled by a first clock having a first terminal and a second terminal, the first terminal being connected to the second terminal of the first sampling capacitor, the second terminal being used for receiving a first input signal;
a first reference input switch controlled by a second clock having a first terminal and a second terminal, the first terminal being connected to the second terminal of the first sampling capacitor, the second terminal being used for receiving a first reference signal;
a first input reset switch controlled by a third clock having a first terminal and a second terminal, the first terminal being connected to the first input terminal of the operational amplifier, the second terminal being used for receiving a common signal;
a first reference reset switch controlled by a reset clock having a first terminal and a second terminal, the first terminal being connected to the second terminal of the first reference input switch, the second terminal being used for receiving the common signal, the first clock, the second clock, and the reset clock each being out of phase with each other; and
a first feedback network connected between the first input terminal of the operational amplifier and the first output terminal of the operational amplifier.
1 Assignment
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Accused Products
Abstract
A switched capacitor circuit of a pipeline analog to digital converter. The pipeline ADC includes a clock generator, a signal reference circuit, and a plurality of switched capacitor circuit. Each switched capacitor includes an operational amplifier, a first sampling capacitor, a first signal input switch, a first reference input switch, a first reference reset switch, and a first feedback network. A method for operating the switched capacitor circuit includes after the first reference input switch turning off, turning on the first signal input switch to transmit a first input signal to the first sampling capacitor and turning on the first reference reset switch to transmit a common signal to a second terminal of the first reference input switch, turning off the first reference rest switch then turning off the first signal input switch, and after the first signal input switch turning off, turning on the first reference input switch.
45 Citations
15 Claims
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1. A switched capacitor circuit comprising:
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an operational amplifier having a first input terminal and a first output terminal; a first sampling capacitor having a first terminal and a second terminal, the first terminal being connected to the first input terminal of the operational amplifier; a first signal input switch controlled by a first clock having a first terminal and a second terminal, the first terminal being connected to the second terminal of the first sampling capacitor, the second terminal being used for receiving a first input signal; a first reference input switch controlled by a second clock having a first terminal and a second terminal, the first terminal being connected to the second terminal of the first sampling capacitor, the second terminal being used for receiving a first reference signal; a first input reset switch controlled by a third clock having a first terminal and a second terminal, the first terminal being connected to the first input terminal of the operational amplifier, the second terminal being used for receiving a common signal; a first reference reset switch controlled by a reset clock having a first terminal and a second terminal, the first terminal being connected to the second terminal of the first reference input switch, the second terminal being used for receiving the common signal, the first clock, the second clock, and the reset clock each being out of phase with each other; and a first feedback network connected between the first input terminal of the operational amplifier and the first output terminal of the operational amplifier. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An analog to digital converter comprising:
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a clock generator for generating a first clock, a second clock, a third clock, and a reset clock, wherein the first clock, the second clock, and the reset clock are each out of phase with each other; a reference signal circuit for generating a first reference signal, a second reference signal, and a common signal; and a plurality of switched capacitor circuits connected in series and connected between an analog input terminal and a digital output terminal, each of the switched capacitor circuits comprising; an operational amplifier having a first input terminal and a first output terminal; a first sampling capacitor having a first terminal and a second terminal, the first terminal being connected to the first input terminal of the operational amplifier; a first signal input switch controlled by a first clock having a first terminal and a second terminal, the first terminal being connected to the second terminal of the first sampling capacitor, the second terminal being used for receiving a first input signal; a first reference input switch controlled by a second clock having a first terminal and a second terminal, the first terminal being connected to the second terminal of the first sampling capacitor, the second terminal being used for receiving a first reference signal; a first input reset switch controlled by a third clock having a first terminal and a second terminal, the first terminal being connected to the first input terminal of the operational amplifier, the second terminal being used for receiving a common signal; a first reference reset switch controlled by a reset clock having a first terminal and a second terminal, the first terminal being connected to the second terminal of the first reference input switch, the second terminal being used for receiving the common signal; and a first feedback network connected between the first input terminal and the first output terminal of the operational amplifier, wherein a first input terminal of an operational amplifier within each of the switched capacitor circuits connected in series is connected to a second terminal of a first signal input switch of a next switched capacitor circuit of the switched capacitor circuits connected in series, a second input terminal of a first signal input switch within a first of the switched capacitor circuits connected in series is connected to the analog input terminal, and a first output terminal of an operational amplifier within a last of the switched capacitor circuits connected in series is connected to the digital output terminal. - View Dependent Claims (9, 10, 11)
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12. A method of operating a switched capacitor circuit, the switched capacitor circuit comprising an operational amplifier, a first sampling capacitor, a first signal input switch, a first reference input switch, a first reference reset switch, and a first feedback network, the method comprising:
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after turning off the first reference input switch, turning on the first signal input switch to transmit a first input signal to the first sampling capacitor and turning on the first reference reset switch to transmit a common signal to a second terminal of the first reference input switch; turning off the first reference reset switch, and then turning off the first signal input switch; and turning on the first reference input switch after turning off the first signal input switch. - View Dependent Claims (13, 14, 15)
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Specification