| 摘要 |
<p>An adaptive proportional integral control loop (209, 210) provides an accurate measurement of input ot output sampling rates for use in asynchronous sampling rate conversion. An input counter (200) counts inputs samples and its output is sampled at the output sampling rate by a latch (201). The output of the latch (201) is passed through a closed loop circuit (210) comprising variable gain (203, 205) and integrator (208) sections. The output of the integrator can be used to steeer the co-efficients of a polyphase filter. The invention has the advantages of a fast settling time and good quantisation noise attenuation.</p> |
