| 摘要 |
PURPOSE:To decrease the change in the output signal amplitude due to the fluctuation in power supply voltage, by providing a follow-up power supply in which the voltage or current changes in follow-up to the power supply voltage. CONSTITUTION:An output voltage of a follow-up voltage source 24 follows up the change in a power supply 7. Thus, a comparison voltage of a comparator 5 being an output of the follow-up voltage source 24 is changed simultaneously with the change in the power supply 7, thus the difference between a DC bias voltage at an output terminal 3 and a comparison voltage of the comparator 5 is constant. Then, an output signal amplitude change due to the fluctuation in the power supply voltage is reduced. Further, a follow-up current source 25 in which the current value is changed with to the voltage change in the power supply 7 is provided. Thus, the DC bias voltage change at the output terminal 3 is decreased. As a result, the change in the output signal amplitude due to the fluctuation in the power supply voltage is reduced. |
