High speed analog to digital converter
AssigneeATI International SRL
InventorsSaeed Abassi, Fangxing Wei, Michael Roden
Life of this patent
Estimating the term…
Abstract
An analog to digital converter having a group of subrange analysis blocks and reference voltage and offset voltage selection blocks. Each subrange analyses block produces an output representative of a range of bits in a digital output of the analog digital converter. The reference voltage and offset voltage selection blocks enable the operating conditions for the next subrange analysis block to be optimized for both linearity and operating speed.
Claims24
An analog to digital converter (ADC) comprising:
- a sampling device for producing a sample of an analog signal;
- a plurality of subrange analysis blocks, each subrange block producing an output representing a subrange of a digital output of the ADC;
- a decoder for receiving the outputs of each subrange block and producing the digital output;
- a reference voltage selection block for producing a reference voltage out of a set of reference voltages representing a magnitude of the analog signal sample;
- and
- wherein the reference voltage represents a magnitude of the analog signal at a resolution of one of the subrange blocks for use by another of the subrange blocks and a result of the subtraction is offset such that the offset result is in a midrange of a comparitor.
A reference voltage selection block for use in an analog to digital converter, the reference voltage selection block receives an input signal which enables selection of a reference voltage out of a set of reference voltages, the reference voltage selection block comprising:
- a plurality of operational amplifiers, each amplifier configured to produce a unique subset of the reference voltage set and having a same maximum voltage swing of 125 mV;
- and
- a decoder and analog switches for receiving the input signal and selecting one of the operational amplifiers and one reference voltage of that operational amplifier reference voltage subset so that the selected one amplifier produces the selected reference voltage.
An analog to digital converter (ADC) comprising:
- a sampling device for producing a sample of an analog signal;
- a plurality of subrange analysis blocks, each subrange block producing an output representing a subrange of a digital output of the ADC and having a plurality of comparitors, each comparitor for comparing a processed version of the sample with one of a respective plurality of reference voltages;
- and
- a decoder for receiving the outputs of each subrange block and producing the digital output;
- and
- wherein:
- for each comparitor in odd ones of the subrange blocks, when the processed version is less than the reference voltage, that comparitor produces a positive signal;
- for each comparitor in even ones of the subrange blocks, when the processed version is less than the reference voltage, that comparitor produces a negative signal;
- the decoder receives the positive signal from each comparitor producing the positive signals and produces the digital output based on in part the received positive signals;
- and
- the decoder receives the negative signal from each comparitor producing the negative signals and produces the digital output based on in part the received negative signals.
Dependencies are inferred from the claim text.