Method and apparatus for A/D conversion
AssigneeInfineon Technologies AG
InventorsAndreas Wiesbauer, Luis Hernandez, David San Segundo Bello, Antonio Di Giandomenico
Life of this patent
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Abstract
A method and an apparatus for converting an analog input signal into a digital output signal using a sigma-delta modulator architecture with a digital tracking filter. The digital tracking filter may have and order greater than one, and the signal and noise transfer functions of the sigma-delta modulator architecture are chosen to provide a sigma-delta modulator architecture with a high dynamic range even if a relatively low oversampling ratio is used.
Claims40
A method for converting an analog input signal to a digital output signal, the method comprising:
- forming a difference signal between the analog input signal and an analog estimate signal of the analog input signal;
- filtering with a first filter function and quantizing the difference signal to obtain a quantized difference signal;
- filtering the quantized difference signal with a second filter function having an order greater than one to obtain a digital estimate signal of the analog input signal, wherein the second filter function is a second order or third order filter function;
- and
- converting the digital estimate signal to the analog estimate signal.
(canceled)
A method for converting an analog input signal to a digital output signal, the method comprising:
- scaling the analog input signal with a scaling factor K;
- forming a difference signal between the scaled analog input signal and an analog estimate signal of the analog input signal;
- filtering with a first filter function and quantizing the difference signal to obtain a quantized difference signal;
- filtering the quantized difference signal with a second filter function to obtain a digital estimate signal of the analog input signal;
- and
- converting the digital estimate signal to the analog estimate signal, wherein the scaling factor is
- K
- =
- 1
-
- STF
- 1
-
- (
-
- jω
- 0
- )
-
- ,
- wherein STF 1 is a signal transfer function defined between the quantized difference signal and the analog input signal and ω0 is a frequency at which STF1 has a maximum gain within a given signal band of interest of the analog input signal.
A method for converting an analog input signal to a digital output signal, the method comprising:
- forming a difference signal between the analog input signal and an analog estimate signal of the analog input signal;
- filtering with a first filter function and quantizing the difference signal to obtain a quantized difference signal;
- filtering the quantized difference signal with a second filter function to obtain a digital estimate signal of the analog input signal;
- and
- converting the digital estimate signal to the analog estimate signal;
- wherein a signal transfer function defined between the quantized difference signal and the analog input signal and a noise transfer function defined between the quantized difference signal and quantization noise introduced during the quantizing of the difference signal have common zeros.
An apparatus configured to convert an analog input signal to a digital output signal, the apparatus comprising:
- a first filter configured to filter a difference signal between the analog input signal and an analog estimate signal of the analog input signal;
- a quantizer configured to quantize the difference signal filtered by the first filter to obtain a quantized different signal;
- a second filer having an order greater than one, the second filter configured to obtain a digital estimate signal of the analog input signal, and wherein the second filter is a second order or third order filter;
- and
- a digital/analog converter configured to convert the digital estimate signal into the analog estimate signal.
(canceled)
An apparatus configured to convert an analog input signal to a digital output signal, the apparatus comprising:
- an amplifier configured to scale the analog input signal with a scaling factor K;
- a first filter configured to filter a difference signal between the scaled analog input signal and an analog estimate signal of the analog input signal;
- a quantizer configured to quantize the filtered difference signal to obtain a quantized difference signal;
- a digital second filter configured to filter the quantized difference signal to obtain a digital estimate signal of the analog input signal;
- and
- a digital/analog converter configured to convert the digital estimate signal to the analog estimate signal,
- wherein the scaling factor is
- K
- =
- 1
-
- STF
- 1
-
- (
-
- jω
- 0
- )
-
- ,
- wherein STF1 is a signal transfer function defined between the quantized difference signal and the analog input signal and ω0 is a frequency at which STF1 has a maximum gain within a given signal band of interest of the analog input signal.
An apparatus configured to convert an analog input signal to a digital output signal, the apparatus comprising:
- a first filter configured to filter a difference signal between the analog input signal and an analog estimate signal of the analog input signal;
- a quantizer configured to quantize the filtered difference signal to obtain a quantized difference signal;
- a second filter configured to filter the quantized difference signal to obtain a digital estimate signal of the analog input signal;
- and
- a digital/analog converter configured to convert the digital estimate signal to the analog estimate signal,
- wherein a signal transfer function, which is defined between the quantized digital signal and the analog input signal, and a noise transfer function, which is defined between the quantized digital signal and quantization noise introduced by the quantizer, have common zeros.
Dependencies are inferred from the claim text.