What is an inverse sinc filter? Why is it needed?

Hi tdas,

Check out the following link, starting on page 40 of the PDF, or 6.36 in the document itself. Essentially, the output of the DAC has a spectrum of sin(x)/x. This is called the sinc function. What it means to us, is that there will be an amplitude error vs. frequency as you approach the nyquist frequency. An inverse sinc filter will correct for these amplitude errors and (try to) provide a constant amplitude out vs. frequency.

http://www.analog.com/library/analogdialogue/archives/43-09/EDCh%206%20Converter.pdf

Tim

Hi tdas,

Check out the following link, starting on page 40 of the PDF, or 6.36 in the document itself. Essentially, the output of the DAC has a spectrum of sin(x)/x. This is called the sinc function. What it means to us, is that there will be an amplitude error vs. frequency as you approach the nyquist frequency. An inverse sinc filter will correct for these amplitude errors and (try to) provide a constant amplitude out vs. frequency.

http://www.analog.com/library/analogdialogue/archives/43-09/EDCh%206%20Converter.pdf

Tim