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== Introduction == | == Introduction == | ||
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| + | With microprocessors becoming ever increasingly faster, smaller, and cheaper, it is preferable to use digital signal processing as a way to compensate for distortions caused by analog circuitry. One area that this can be applied is in signal reconstruction, where a low pass analog filter is used on the output of a digital-to-analog converter to attenuate unwanted frequency components above the Nyquist frequency. | ||
| + | |||
| + | The problem with analog low pass filters is that higher the order, the more resistors, capacitors, and op-amps are required in its construction. More circuit components means more circuit board space, which is a precious commodity with today's hand-held devices. | ||
| + | |||
| + | Here, it will be explained how up-sampling can be used to relax requirements on analog low pass filter design while decreasing signal distortion. | ||
== A Representative DT Signal == | == A Representative DT Signal == | ||
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[[Image:Xd_w_plot.png]] | [[Image:Xd_w_plot.png]] | ||
| − | == Without | + | == Without Up-sampling == |
[[Image:Dac_diag.png]] | [[Image:Dac_diag.png]] | ||
[[Image:W1_f_plot.png]] | [[Image:W1_f_plot.png]] | ||
| − | == With | + | == With Up-sampling == |
[[Image:Upsampling_diag.png]] | [[Image:Upsampling_diag.png]] | ||
Revision as of 17:39, 22 September 2009
Contents
Introduction
With microprocessors becoming ever increasingly faster, smaller, and cheaper, it is preferable to use digital signal processing as a way to compensate for distortions caused by analog circuitry. One area that this can be applied is in signal reconstruction, where a low pass analog filter is used on the output of a digital-to-analog converter to attenuate unwanted frequency components above the Nyquist frequency.
The problem with analog low pass filters is that higher the order, the more resistors, capacitors, and op-amps are required in its construction. More circuit components means more circuit board space, which is a precious commodity with today's hand-held devices.
Here, it will be explained how up-sampling can be used to relax requirements on analog low pass filter design while decreasing signal distortion.
A Representative DT Signal
Without Up-sampling
With Up-sampling
