Pipeline analog to digital converter and a residue amplifier for a pipeline analog to digital converter
AssigneeAnalog Devices, Inc.
InventorsDerek HUMMERSTON, Christopher Peter Hurrell, Colin Lyden
Life of this patent
Estimating the term…
Abstract
A pipeline analog to digital converter comprising: a first analog to digital converter for determining a first part of an analog to digital conversion result, and for forming a residue signal; an amplifier for amplifying the residue signal, the amplifier including at least one offset sampling capacitor for sampling an offset of the amplifier, wherein at least one resistance is associated with the at least one capacitor so as to form a filter, and the at least one resistor is variable such that an amplifier bandwidth can be switched between a first bandwidth and a second bandwidth less than the first bandwidth during sampling of the offset.
Claims21
A pipeline analog to digital converter comprising:
- a first analog to digital converter for determining a first part of an analog to digital conversion result, and for forming a residue signal;
- an amplifier for amplifying the residue signal, the amplifier including at least one offset sampling capacitor for sampling an offset of the amplifier,
- wherein at least one resistance is associated with the at least one capacitor so as to form a filter, and the at least one resistance is variable such that the filter can be switched between a first bandwidth and a second bandwidth less than the first bandwidth.
A method of operating a pipeline analog to digital converter comprising a first analog to digital conversion stage, a second analog to digital conversion stage, a residue amplifier for amplifying a residue from the first analog to digital conversion stage for use as an input to the second analog to digital conversion stage, and wherein the residue amplifier is further under the control of the controller to perform auto-zeroing and is switchable between a first bandwidth and a second bandwidth having a second bandwidth time constant, and wherein, in use, the residue amplifier is placed in an auto-zero mode for at least some of the time when it is not required to amplify the residue, and a predetermined period before amplification of the residue is required the bandwidth of the residue amplifier is reduced during its auto-zeroing operation, or the amplifier is operated at the reduced bandwidth during the entirety of the auto-zeroing operation and then subsequently is operated at the first bandwidth during the residue amplification phase.
A pipeline analog to digital converter, comprising:
- a first analog to digital converter for determining a first part of an analog to digital conversion result and for forming a residue signal;
- and
- an amplifier for amplifying the residue, the amplifier comprising a first stage, a second stage and an offset sampling capacitor interconnecting an output of the first stage to an input of the second stage, and wherein an impedance comprising at least one of a resistor and a capacitor is associated with the offset sampling capacitor and is switchable or variable so as to co-operate with the offset sampling capacitor to enable a bandwidth of the amplifier to be switched between first and second bandwidths.
Dependencies are inferred from the claim text.