Variable interpolator for non-uniformly sampled signals and method

A variable interpolator having an interpolation factor L for performing an interpolation of an input signal, where L is variable and includes a minimum value, the variable interpolator comprising:

• a differentiator having an input and an output, wherein the differentiator is responsive to the interpolator input signal on the differentiator input for performing a differentiator portion of the interpolation and for providing a differentiator result signal on the differentiator output;
• a chopper coupled with the differentiator for chopping the differentiator result signal as a function of the minimum value of L, wherein for an interpolator input signal that contains non-uniformly sampled signals in which there exists at least one sample of a shortest duration and at least one sample of a duration that extends beyond the shortest duration, the minimum value of L corresponds to the duration of the sample of shortest duration, and wherein for an interpolator input signal that contains uniformly sampled signals in which the samples are of a fixed duration, the minimum value of L corresponds to the fixed duration, wherein the chopper includes a chopper input for receiving the differentiator result signal, an interpolator strobe input for receiving an interpolator strobe signal, a clock input for receiving a clock signal, and an output, wherein the chopper is responsive to the differentiator result signal on the chopper input (i) for chopping the differentiator result signal as a function of the minimum value of L, the interpolator strobe signal, and the clock signal and (ii) for providing a chopped differentiator result signal on the chopper output;
• and
• an integrator having an input and an output, wherein the integrator is responsive to the chopped differentiator result signal on the integrator input for performing an integrator portion of the interpolation and for providing an integrator result signal on the integrator output, the integrator output corresponding to an output of the variable interpolator.

A variable interpolator having an interpolation factor L for performing an interpolation of an input signal, where L is variable and includes a minimum value, the variable interpolator comprising:

• a differentiator having an input and an output, wherein the differentiator is responsive to the interpolator input signal on the differentiator input for performing a differentiator portion of the interpolation and for providing a differentiator result signal on the differentiator output;
• a chopper coupled with the differentiator for chopping the differentiator result signal as a function of the minimum value of L, wherein for an interpolator input signal that contains non-uniformly sampled signals in which there exists at least one sample of a shortest duration and at least one sample of a duration that extends beyond the shortest duration, the minimum value of L corresponds to the duration of the sample of shortest duration, and wherein for an interpolator input signal that contains uniformly sampled signals in which the samples are of a fixed duration, the minimum value of L corresponds to the fixed duration, wherein the chopper comprises a portion of the differentiator;
• and
• an integrator having an input and an output, wherein the integrator is responsive to the chopped differentiator result signal on the integrator input for performing an integrator portion of the interpolation and for providing an integrator result signal on the integrator output, the integrator output corresponding to an output of the variable interpolator.

An interpolator comprising:

• a fixed interpolator having an interpolation factor K for performing an interpolation on an input signal, where K is a fixed value, the fixed interpolator having an input and an output, wherein responsive to the input signal on the fixed interpolator input, the fixed interpolator performs an interpolation on the input signal and provides a first interpolated signal on the fixed interpolator output;
• and
• a variable interpolator having an interpolation factor L for performing a variable interpolation of the first interpolated signal, where L is variable and includes a minimum value, wherein the variable interpolator comprises:
• a differentiator having an input and an output, wherein the differentiator is responsive to the first interpolated signal on the differentiator input for performing a differentiator portion of the variable interpolation and for providing a differentiator result signal on the differentiator output;
• a chopper coupled with the differentiator for chopping the differentiator result signal as a function of the minimum value of L, wherein for a first interpolated signal that contains non-uniformly sampled signals in which there exists at least one sample of a shortest duration and at least one sample of a duration that extends beyond the shortest duration, the minimum value of L corresponds to the duration of the sample of shortest duration, and wherein for a first interpolated signal that contains uniformly sampled signals in which the samples are of a fixed duration, the minimum value of L corresponds to the fixed duration, wherein the chopper chops the differentiator result signal as a function of the minimum value of L by forcing to zero any portion of a sample of the differentiator result signal that may extend beyond the shortest duration;
• and
• an integrator having an input and an output, wherein the integrator is responsive to the chopped differentiator result signal on the integrator input for performing an integrator portion of the variable interpolation and for providing an integrator result signal on the integrator output, the integrator output corresponding to an output of the variable interpolator.

A method of performing a variable interpolation of an input signal with an interpolation factor L, where L is variable and includes a minimum value, the method comprising:

• performing a differentiator portion of the interpolation in response to the input signal and providing a differentiator result signal;
• chopping the differentiator result signal as a function of the minimum value of L to provide a chopped differentiator result signal, wherein for a differentiator result signal that contains non-uniformly sampled signals in which there exists at least one sample of a shortest duration and at least one sample of a duration that extends beyond the shortest duration, the minimum value of L corresponds to the duration of the sample of shortest duration, and wherein for a differentiator result signal that contains uniformly sampled signals in which the samples are of a fixed duration, the minimum value of L corresponds to the fixed duration, wherein chopping the differentiator result signal as a function of the minimum value of L comprises forcing to zero any portion of a sample of the differentiator result signal that may extend beyond the shortest duration;
• and
• performing an integrator portion of the interpolation in response to the chopped differentiator result signal and providing an integrator result signal, the integrator result signal corresponding to an output signal of the variable interpolation.

A method of performing a variable interpolation of an input signal with an interpolation factor L, where L is variable and includes a minimum value, the method comprising:

• performing a differentiator portion of the interpolation in response to the input signal and providing a differentiator result signal;
• chopping the differentiator result signal as a function of the minimum value of L to provide a chopped differentiator result signal, wherein for a differentiator result signal that contains non-uniformly sampled signals in which there exists at least one sample of a shortest duration and at least one sample of a duration that extends beyond the shortest duration, the minimum value of L corresponds to the duration of the sample of shortest duration, and wherein for a differentiator result signal that contains uniformly sampled signals in which the samples are of a fixed duration, the minimum value of L corresponds to the fixed duration, wherein chopping the differentiator result signal further comprises (i) chopping the differentiator result signal as a function of the minimum value of L, an interpolator strobe signal, and a clock signal and (ii) providing the chopped differentiator result signal;
• and
• performing an integrator portion of the interpolation in response to the chopped differentiator result signal and providing an integrator result signal, the integrator result signal corresponding to an output signal of the variable interpolation.