Circuit and method for generating reference signals for hybrid analog-to-digital convertors
AssigneeSTMicroelectronics International N.V.
InventorsAshish Kumar, Chandrajit Debnath, Pratap Narayan Singh
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Abstract
An embodiment circuit includes a first reference source configured to provide a first reference signal to an analog-to-digital convertor (ADC). The circuit also includes a filter coupled to an output of the first reference source and configured to filter the first reference signal to produce a filtered first reference signal. The circuit further includes a second reference source coupled to an output of the filter. The second reference source is configured to provide a second reference signal to the ADC, and the second reference signal is generated based on the filtered first reference signal.
Claims19
A circuit configured to generate a plurality of reference signals for an analog-to-digital convertor (ADC), the circuit comprising:
- a first reference source comprising a first output terminal and a second output terminal, the first reference source being configured to generate a first reference voltage between the first output terminal and the second output terminal, the first reference voltage comprising a transient signal, the first reference voltage being configured to be provided as a first reference signal to the ADC;
- a filter comprising a first input terminal coupled to the first output terminal of the first reference source, and a second input terminal coupled to the second output terminal of the first reference source, the filter being configured to remove the transient signal from the first reference voltage to produce a filtered first reference signal between a first output terminal and a second output terminal of the filter;
- a first voltage follower having an input terminal coupled to the first output terminal of the filter;
- and
- a second voltage follower having an input terminal coupled to the second output terminal of the filter, the first voltage follower and the second voltage follower being configured to produce a second reference voltage between output terminals of the first voltage follower and the second voltage follower, the second reference voltage being configured to be provided as a second reference signal to the ADC.
A circuit configured to generate a plurality of reference signals for an analog-to-digital convertor (ADC), the circuit comprising:
- a hybrid analog-to-digital convertor (ADC) comprising a first ADC architecture coupled to a second ADC architecture different from the first ADC architecture, the first ADC architecture configured to receive an analog signal;
- a first reference driver comprising a first pair of output terminals, the first reference driver being configured to generate a first reference signal between the first pair of output terminals, the first reference signal for determining M most significant bits of an N-bit digital representation of the analog signal;
- a filter comprising input terminals coupled to the first pair of output terminals, the filter being configured to remove a transient signal generated at the first pair of output terminals by capacitor-switching in the first ADC architecture, the filter having a second pair of output terminals;
- and
- a second reference driver comprising input terminals coupled to the second pair of output terminals, the second reference driver being configured to generate a second reference signal between a third pair of output terminals, the second reference signal for determining (N-M) least significant bits of the N-bit digital representation of the analog signal.
Dependencies are inferred from the claim text.