Method for converting an analog input signal, and analog-to-digital converter
AssigneeInfineon Technologies AG
InventorsOlaf Stroble, Victor Dias
Life of this patent
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Abstract
A method for converting an analog input signal into a digital value with successive approximation. A first comparison operation is provided before a first approximation, which subdivides a predefined input voltage interval into five partial intervals according to four reference potentials. During the comparison operation, a partial voltage interval determined is used in the ensuing approximation for the selection of a new reference potential pair to be used. This method enables higher sampling rates. At the same time, the range of the input signal is increased.
Claims26
A method for converting an analog input signal into a digital value comprising:
- performing an initial comparison, which compares the input signal with initial partial reference potentials and generates an initial control signal according to the comparison;
- performing a first approximation, which compares the input signal with first partial reference potentials and generates a first control signal according to the first approximation;
- performing one or more additional approximations, which compare the input signal with additional partial reference potentials and generate one or more additional control signals according to the one or more additional approximations;
- performing a final approximation, which compares the input signal with final partial reference potentials and generates a final control signal according final approximation;
- and
- generating the digital value according to the initial control signal, the one or more control signals, and the final control signal.
An analog-to-digital converter comprising:
- an input for an analog input signal;
- a first converter stage comprising a comparator circuit that compares the analog input signal with first reference potentials and outputs an initial control signal according to the comparison and a sample and hold circuit that provides the analog input signal as an initial output signal;
- one or more additional converter stages that operate sequentially on the initial output signal to compare the initial output signal to additional partial reference potentials and generate one or more additional control signals and one or more additional output signals, the one or more additional converter stages respectively comprising a comparator circuit;
- and
- a logic circuit that provides a digital value according to the initial control signal and the one or more additional control signals.
An analog-to-digital converter comprising:
- a first converter stage having a first sample and hold circuit and a first comparator circuit, wherein the first sample and hold circuit holds a sample of the input signal during a first phase of a time period and provides the sample during a second phase of the time period, wherein the first comparator circuit compares the sample to first partial reference potentials to generate a first control signal during the second phase;
- a second converter stage downstream from the first converter stage having a second sample and hold circuit and a second comparator circuit, wherein the second sample and hold circuit holds the sample during the first phase and provides the sample during the second phase, wherein the second comparator circuit compares the sample to second partial reference potentials to generate a second control signal during the second phase;
- a final converter stage downstream from the second converter stage having a final comparator circuit, wherein the final comparator circuit compares the sample to final partial reference potentials to generate a final control signal during the second phase;
- and
- a logic circuit to generate a digital value for the sample according to at least the first control signal, the second control signal, and the final control signal.
Dependencies are inferred from the claim text.