| 摘要 |
PROBLEM TO BE SOLVED: To provide an identification level automatic adjustment circuit that always adjusts the identification level with respect to an output signal from an equalization amplifier circuit to a proper level. SOLUTION: This identification level automatic adjustment circuit is provided with an identification signal generating section 51, that outputs three kinds of identification signals corresponding to a desired identification sensitivity, comparators 52a, 52b, 52c that compare an output signal from an equalization amplifier circuit 30 with the signal levels of the identification signals, D-FF 53a, 53b, 53c that synchronize the comparison result with a clock signal, an EX-OR 54 that exclusively ORs output values of the D-FF 53a, 53b, 53c, and an offset control section 55 that adjusts all of the signal levels of the 3 kinds of the identification signals so as to be included in a level of the output signal from the equalization amplifier circuit, by controlling the identification signal generating section 51 based on the output signal from the D-FF 53a, 53b, 53c and the output signal from the EX-OR 54, and one identification signal among the three kinds of the identification signals, whose signal level is a median is outputted as the identification level adjustment signal used by an identification recovery circuit. |
