Patent ID: 7449669
Filing Date: 2008-11-11
Classification: H03F

Abstract:
1. A receiving apparatus comprising: a light receiving element which receives an optical signal and generates a current signal dependent on the optical signal; a conversion unit which converts the current signal into a voltage signal; a reference voltage generation unit which generates a reference voltage; a threshold voltage generation unit which generates, based on the voltage signal outputted from the conversion unit and the reference voltage outputted from the reference voltage generation unit, a threshold voltage signal having an amplitude smaller than an amplitude of the voltage signal with reference to substantially the center of amplitude range of the voltage signal and delayed by a predetermined time period from the voltage signal; and a comparison unit which compares the voltage signal outputted from the conversion unit with the threshold voltage signal outputted from the threshold voltage generation unit, wherein the threshold voltage generation unit includes: a level shift circuit which converts voltage level of a first input voltage; voltage dividing circuit which divides second and third input voltages to generate a divided voltage having voltage level between the second and third input voltages; and a delay circuit which delays a fourth input voltage by the predetermined time, the voltage signal outputted from the conversion unit being the second input voltage or the fourth input voltage, the reference voltage being the first input voltage or the third input voltage, and the threshold voltage signal being outputted from the level shift circuit, the voltage dividing circuit or the delay circuit.