| 摘要 |
<p>PROBLEM TO BE SOLVED: To make the symmetry of upper and lower peak level signals unchanged by generating the respective threshold voltage values on upper and lower sides and the reference voltage value for comparison to the upper peak signal and controlling the amplification factor of an output amplifier as to the upper peak signal. SOLUTION: The bias of a reference voltage is set as a voltage on the opposite side of the output of a load resistance RL through a voltage follower 14 and the output signal level of a current output amplifier 11 is also a shifted state to a ground side. Even when the amplitude reference level of the output signal is shifted to the ground side, since the amplification factor is largely reduced to the output voltage of the current output amplifier 11 exceeding the voltage VP at the connection point P by a gain control circuit 12, the symmetry of the upper and lower signals of peak levels is made to be unchanged and the relation between the input signal to a hysterisis comparator and the respective threshold voltage values on the upper and lower sides is ensured.</p> |
