摘要 |
PROBLEM TO BE SOLVED: To perform peak detection on a differential input signal with the differential signal left as it is, to resultantly obtain a DC level signal also as a differential signal, and to facilitate the setting of a time constant up to the completion of the peak detection. SOLUTION: A differential comparator circuit 10 of complete differential inputting is formed by pairing parallel transistors with their sources and drains put to common connection, a differential signal is inputted into parallel transistors 11 and 12 on one side to detect their crest values, and a differential charge pump circuit 30 is driven according to an output current signal from the comparator circuit 10. Based on the current signal, the pump circuit 30 causes a charge current to pass through a capacitive element 41 which is a load. Its terminal voltage is fed back to parallel transistors 13 and 14 on the other side of the comparator circuit 10, thereby inputting a differential DC signal thereinto. In the comparator circuit 10, two differential potentials are compared with each other to obtain a peak detection result as a differential signal. COPYRIGHT: (C)2006,JPO&NCIPI
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