发明名称 |
ZERO-CROSSING COMPARATORS WITH THRESHOLD VALIDATION |
摘要 |
In carrier and timing recovery systems for high performance data modems it is essential to employ threshold comparators and to be able to determine accurately zero-crossing instants. The circuit of the invention comprises a comparator with feedback which produces a positive transition of the comparator output in response to the negative zero-crossing transition of the input signal on condition that the previous half-cycle of the input signal has exceeded the positive reference threshold. In a practical arrangement two comparators are provided together with a pair of bistable storage elements which produces a narrow pulse in response to the negative zero-crossing transition of an input signal provided that the input signal has exceeded the positive reference threshold applied to the second comparator. |
申请公布号 |
DE3070515(D1) |
申请公布日期 |
1985.05.23 |
申请号 |
DE19803070515 |
申请日期 |
1980.09.05 |
申请人 |
PLESSEY OVERSEAS LIMITED |
发明人 |
GALPIN, ROBERT KEITH PORTWAY |
分类号 |
H03K5/1536;H04L7/033;(IPC1-7):H03K5/153;H03K17/13 |
主分类号 |
H03K5/1536 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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