| 摘要 |
PURPOSE:To quickly rise the output voltage of an APC(automatic power control) circuit when transmission rises by connecting a capacitor with capacity smaller than that of the capacitor of a phase compensation circuit to the capacitor in series, and connecting a switch circuit inparallel with the capacitor. CONSTITUTION:Ordinarily, the capacitor C4 is short-circuited by turning on the switch circuit SW. When the circuit is started from a power saving mode, the switch circuit SW is turned off by applying a control signal CNT for a short time, and the capacitors C1 and C4 are connected in series. Thereby, since a discharge time constant can be decreased, the input voltage of a differential amplifier circuit 5 can quickly arrive at a reference voltage Vref, and an APC loop can be formed, and the rise characteristic of an APC operation can be improved. |
