Cyclic analog to digital converter
AssigneeIntel Corporation
InventorsBryan Casper, Craig Petrie
Life of this patent
Estimating the term…
Abstract
A cyclic analog to digital converter (ADC) circuit operates to convert an analog input voltage into a digital output word. The ADC circuit includes an amplifier and capacitors configured as an integrator.
Claims27
An analog to digital converter comprising:
- an amplifier;
- a first capacitor coupled to an input node of the amplifier;
- a second capacitor coupled between the input node of the amplifier and an output node of the amplifier, wherein the second capacitor has a capacitance value substantially equal to the first capacitor;
- a feedback path to conditionally couple the output node of the amplifier to the first capacitor;
- a comparator coupled to the output node of the amplifier to provide a digital output value;
- and
- at least one switching element responsive to the digital output value, the at least one switching element coupled to the first capacitor to apply a reference voltage to the first capacitor.
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An analog to digital converter having an input capacitor and input switch network that samples a residue voltage on a first phase of a clock and samples a reference voltage on a second phase of the clock, an amplifier and feedback capacitor that integrate a difference between the residue voltage and the reference voltage, and a comparator to provide a digital output signal from the residue voltage, wherein the input switch network includes at least one switch responsive to the digital output signal.
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An analog to digital converter having an input capacitor and input switch network that samples a residue voltage on a first phase of a clock and samples a reference voltage on a second phase of the clock, an amplifier and feedback capacitor that integrate a difference between the residue voltage and the reference voltage, a second input capacitor and a second input switch network to provide a differential input and a comparator to provide a digital output value from the residue signal, wherein the first and second input switch networks are coupled to be responsive to the digital output signal.
A method comprising:
- sampling an input voltage on an input capacitor of a cyclic analog to digital converter;
- integrating a voltage change on the input capacitor to modify a residue signal by a voltage having a magnitude substantially equal to the voltage change;
- feeding back the residue signal to the input capacitor;
- passing the residue signal to a comparator to produce a digital output signal;
- and
- applying a first reference voltage to the input capacitor when the digital output signal has a first value, and applying a second reference voltage to the input capacitor when the digital output signal has a second value.
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An electronic system comprising:
- an antenna;
- and
- an integrated circuit to operate on signals received by the antenna, the integrated circuit including a port circuit having an analog to digital converter that includes an input capacitor and input switch network that samples a residue voltage on a first phase of a clock and samples a reference voltage on a second phase of the clock, an amplifier and feedback capacitor that integrate a difference between the residue voltage and the reference voltage, and a comparator to provide a digital output signal from the residue voltage, wherein the input switch network includes at least one switch responsive to the digital output signal.
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Dependencies are inferred from the claim text.