| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical signal receiving apparatus capable of preventing an output voltage from being saturated, widening the dynamic range and suppressing cost increase. <P>SOLUTION: A comparator 172 of the optical signal receiving apparatus sets on its output and applies its output voltage Vco to a base of a transistor 152 when a peak hold voltage Vph outputted from a peak hold circuit 160 provided to a trans-impedance amplifier 110A is greater than a threshold voltage Vth. Thus, a current flows between a collector and an emitter of the transistor 152. Similarly, a current flows between a collector and an emitter of a transistor 153 on the basis of the peak hold voltage Vph. The impedance in the trans-impedance amplifier 110A is adjusted based thereon and the gain of the trans-impedance amplifier 110A is controlled. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
