| 摘要 |
<p>When the input voltage of a comparator (COMP) changes from its initial value, Vcc, to 1/2 of Vcc due to a decrease in potential at a node (Nl), the output level of the comparator (COMP) is inverted, so that the output level becomes low. When the output level of the comparator (COMP) becomes low, an amplifier part switch (SW3) is connected, causing an optical receiver circuit (1) to enter a semi-activation state. The connection of the amplifier part switch (SW3) also activates a signal detector circuit (SD). When an amplifier part (2) becomes activated, the signal detector circuit (SD) determines whether the output of the amplifier part (2) includes any transport signal. If being to notify to the effect that no transport signal is included, the signal detector circuit (SD) causes a reset switch (SW2) to be connected, thereby resetting a capacitor (C1).</p> |
