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| | The **Shannon** theorem does not, strictly speaking, affect the D/A process, what it does is tell you the minimum sampling frequency you need to use to capture a input signal with a given bandwidth and consequently what the cutoff frequency of your Low Pass Filter circuit needs to be to recover the original signal. |

| | Firstly, in an ideal world, **Shannon's** **interpolation** theorem is a method of exactly calculating a value between sample points however it implies the use of the sinc(x) function which is infinite, therefore, in any real system, an approximation must be used which means the value calculated is never truly exact. |

| | Thus **Shannons** **interpolating** theorem is actually used to enable digital filtering prior to D/A conversion to ease the cost/complexity of the output analogue Low pass filter. |

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