Continuous-time oversampled converter having enhanced immunity to noise

An apparatus comprising:

• a clock source to generate a clock signal in which a noise signal is added to the clock signal as the clock signal is generated and/or routed;
• an oversampled continuous-time analog-to-digital converter to convert an input analog signal to an output digital signal, the oversampled continuous-time analog-to-digital converter comprising:
• a quantizer to quantize a first intermediate signal and generate the output digital signal;
• a first filter to filter the output digital signal and generate a first filtered digital signal, the first filter having a transfer function that has a stop band at a frequency range that includes the frequency of the noise signal or a component of the noise signal;
• a first feedback continuous-time digital-to-analog converter to convert the first filtered digital signal to a first analog representation of the first filtered digital signal;
• and
• a first circuit to generate a second intermediate signal representing a difference between the input analog signal and the first analog representation of the first filtered digital signal;
• wherein the clock signal or a signal derived from the clock signal is used by one or more components of the oversampled continuous-time analog-to-digital converter.

An apparatus comprising:

• an oversampled continuous-time digital-to-analog converter comprising:
• a first filter to filter an oversampled digital signal and generate a filtered oversampled digital signal, the filter having a transfer function that has a stop band at a frequency range that includes the frequency of a noise signal, the stop band being outside of a frequency band of interest;
• a continuous-time digital-to-analog converter to convert the filtered samples to a first analog signal;
• and
• a second filter to filter the first analog signal and generate an output analog signal, the second filter reducing components in the output analog signal having frequencies outside of the frequency band of interest.

An apparatus comprising:

• an oversampled continuous-time analog-to-digital converter to convert an input analog signal to an output digital signal, the oversampled continuous-time analog-to-digital converter comprising:
• a quantizer to quantize a first intermediate signal and generate the output digital signal;
• a first filter to filter the output digital signal and generate a first filtered digital signal, the first filter having a transfer function having a stop band at a frequency range that includes the frequency of a noise signal;
• a first feedback continuous-time digital-to-analog converter to convert the first filtered digital signal to a first analog representation of the first filtered digital signal;
• and
• a first circuit to generate a second intermediate signal representing a difference between the input analog signal and the first analog representation of the first filtered digital signal.

An apparatus comprising:

• an oversampled continuous-time converter to convert an input signal into an output signal having a format that is different from the input signal, the continuous-time oversampled converter comprising:
• a filter to filter an oversampled digital signal and generate a filtered signal, the filter having a transfer function having a stop band at a frequency range that includes a frequency of a noise signal, the stop band being outside of a frequency band of interest;
• and
• a continuous-time digital-to-analog converter to convert the filtered signal to an analog signal.

A method of converting input digital data samples to an output analog signal, the method comprising:

• routing a clock signal having a noise signal;
• filtering oversampled digital data having components outside of a signal band of interest, by using a filter having a transfer function that has a stop band at a frequency that matches the frequency of the noise signal or a component of the noise signal, to generate filtered samples, the stop band being outside of the signal band of interest;
• and
• converting, using a continuous-time digital-to-analog converter, the filtered samples to an output analog signal.

A method of converting an input analog signal to an output digital signal, the method comprising:

• generating a clock signal;
• routing the clock signal, in which a noise signal is added to the clock signal as the clock signal is generated and/or routed;
• quantizing a first intermediate signal and generating an output digital signal;
• filtering the output digital signal and generating a filtered digital signal using a filter having a transfer function that has a stop band at a frequency range that includes the frequency of the noise signal or a component of the noise signal;
• converting, using a feedback continuous-time digital-to-analog converter, the filtered digital signal to an analog representation of the filtered digital signal;
• and
• generating a second intermediate signal representing a difference between an input analog signal and the analog representation of the filtered digital signal.

An apparatus comprising:

• an oversampled continuous-time digital-to-analog converter to convert digital input data to analog output data, the oversampled continuous-time digital-to-analog converter comprising:
• a filter to filter oversampled data and generate filtered data, the filter having a transfer function that has a stop band at a frequency range that is outside a signal band of interest and includes the frequency of a noise component of a clock signal;
• and
• a continuous-time digital-to-analog converter to convert the filtered data to the analog output signal, the continuous-time digital-to-analog converter using the clock signal or another signal derived from the clock signal.

An apparatus comprising:

• an oversampled continuous-time analog-to-digital converter to convert an analog input signal to a digital output signal, the oversampled continuous-time analog-to-digital converter comprising:
• a quantizer to quantize a first intermediate signal and generate the output digital signal;
• a filter to filter the output digital signal and generate a filtered digital signal, the filter having a transfer function that has a stop band at a frequency range that is outside a signal band of interest and includes the frequency of a noise component of a clock signal;
• a feedback continuous-time digital-to-analog converter to convert the filtered digital signal to an analog representation of the filtered digital signal, the continuous-time digital-to-analog converter using the clock signal or another signal derived from the clock signal;
• and
• a circuit to generate a second intermediate signal representing a difference between the analog input signal and the analog representation of the filtered digital signal.