| 摘要 |
The present invention relates to an apparatus for frequency conversion, comprising: an analog-to-digital (A/D) converter, receiving and sampling an input signal according to a sampling frequency for producing a first digital signal, and the sampling frequency and the frequency of the input signal having a correspondence; a sign conversion circuit, used for receiving the first digital signal, and performing a sign conversion on the first digital signal and producing a second digital signal; a first switching module, used for selecting one of the first digital signal and the second digital signal as an output signal according to the sampling frequency; a filter, coupled to the first switching module, used for filtering the output signal from the first switching module, and producing a filter signal; and a second switching module, coupled to the filter, used for outputting the filter signal to a first output path or a second output path alternately according to the sampling frequency. Thereby, according to the present invention, by means of the correspondence between the sampling frequency and the frequency of the input signal, the use of a filter and an A/D converter can be saved, and thus reducing circuit area and cost.
|
