| 摘要 |
PROBLEM TO BE SOLVED: To correspond to large level difference with a simple structure in an infrared data receiving circuit which performs waveform shaping of an output from a photodiode and uses it. SOLUTION: In this data receiving circuit 51, output current of a photodiode 52 is undergone current-voltage conversion by a preamplifier 53, amplified by an amplifier circuit 55, and after that, undrgone waveform shaping in a prescribed threshold voltage Vth by a comparator 61. When a signal voltage Vsig is low, the voltage Vth is made an average value Vav which is generated by LPFs 63 and 68 and when it is high, a voltage that is shifted by a level shift circuit 62 is made a shift value Vsht which is sampled by a peak hold circuit consisting of a differential amplifier 64. Thereby, it can correspond to a large and dynamic range. Also, in such a structure, a capacitor 66 is shared as a capacitor for integration of the LPFs and for hold of the peak hold circuit, and the structure can be simplified so that it may be convenient to make a circuit integrated. |
