Analog to digital converter stage
AssigneeAnalog Devices International Unlimited Company
InventorsRares Bodnar, Asif Ahmad, Christopher Peter Hurrell
Life of this patent
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Abstract
A stage, suitable for use in an analog to digital converter or a digital to analog converter, can have a plurality of slices that can be operated together to form a composite output. The stage can have reduced thermal noise, while each slice on its own has sufficiently small capacitance to respond quickly to changes in digital codes applied to the slice. This feature allows a fast conversion to be achieved without loss of noise performance.
Claims23
A capacitive digital to analog converter (DAC) arrangement for utilization within a data converter, comprising:
- a first DAC slice to receive a signal via an input line of the first DAC slice, the first DAC slice having a first resist ance coupled in series on the input line of the first DAC slice;
- and
- a second DAC slice coupled in parallel with the first DAC slice, the second DAC slice to receive the signal via an input line of the second DAC slice, the second DAC slice having a second resistance coupled in series on the input line of the second DAC slice;
- wherein sampling performance of the first DAC slice matches sampling performance of the second DAC slice.
An analog to digital converter (ADC), comprising:
- an ADC stage to receive an input signal and produce a digital representation of the input signal;
- and
- a residue digital to analog converter (DAC), comprising:
- a first DAC slice coupled to the ADC stage, the first DAC slice to sample the input signal via a first line and the first DAC slice having a first resistance coupled in series with a first switch on the first line;
- and
- a second DAC slice coupled to the ADC stage in parallel with the first DAC slice, the second DAC slice to sample the input signal via a second line and the first DAC slice having a second resistance coupled in series with a second switch on the second line;
- wherein the first DAC slice and the second DAC slice are to form a residue representing a difference between the input signal and a voltage produced by the residue DAC when driven with the digital representation of the input signal from the ADC stage.
A digital to analog converter (DAC) slice for utilization in a data converter, comprising:
- a capacitor coupled to an output of the DAC slice;
- a set of transistors coupled to the capacitor, the set of transistors to operate as a switch to couple the capacitor to different lines of the DAC slice;
- and
- a resistance coupled in series with a transistor of the set of transistors on an input line of the DAC slice;
- wherein a size of the capacitor from a second capacitor in a second DAC slice by a first ratio, and a width to length ratio of the set of transistors differs from a further set of transistors in the further DAC slice by the first ratio.
A digital to analog converter (DAC) slice for utilization in a data converter, comprising:
- a capacitor coupled to an output of the DAC slice;
- a set of transistors coupled to the capacitor, the set of transistors to operate as a switch to couple the capacitor to different lines of the DAC slice;
- and
- the DAC slice is grouped together with further DAC slices to form weighted capacitors;
- and
- each one of the DAC slice and further DAC slices comprises a capacitor and a set of transistors of a unit size.
Dependencies are inferred from the claim text.