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专利名称：OSCILLATION FREQUENCY CONTROL
CIRCUIT
发明人：KIMURA, HIROKI申请号：EP08848867申请日：20081010公开号：EP21287A4公开日：20110504
摘要：To provide a highly stable oscillation frequency control circuit wherein thefrequency thereof is corrected, an adequate range of the input levels of externalreference signals is determined in accordance with temperature characteristics indetecting the external reference signal, and the control voltage to a VCO is controlledwithin and outside the adequate range. An oscillation frequency control circuit includes aselection switch (13) that connects the phase comparator (12) to the loop filter (14) in anexternal reference synchronization mode and that connects the fixed voltage supplyingcircuit (23) to the loop filter (14) in a fixed voltage mode, and a CPU (20) that switches theselection switch (13) to the external reference synchronization mode or to the fixedvoltage mode based on whether the detected voltage of an external reference signallevel is within or outside of the adequate range. (FIG.1)
申请人：NIHON DEMPA KOGYO CO., LTD.
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