| 摘要 |
An infrared receiver is provided to secure the optimum sensitivity by generating pulses respectively for an input noise and an input signals, separating the noise from the signal using the pulse signals, and obtaining fast attenuation for the noise and a sufficient time constant for the signal. An infrared receiver comprises an input part(110), a front-end amplifier(120), an automatic gain control and amplification part(130), a limit amplifier(140), a band pass filter(150), a gain controller(160), the first and second comparators(170,200), the first and second demodulators(180,210), and an output part(190). The input part(110) includes a photo diode to detect an infrared signal inputted from the external and to convert it into an electrical signal. The front-end amplifier(120) amplifies the converted electrical signal. The automatic gain control and amplification part(130) amplifies the output signal of the front-end amplifier(120). The limit amplifier(140) amplifies the amplified signal again. The band pass filter(150) filters an electrical signal having a specific frequency among the output of the limit amplifier(140). The first comparator(170) compares the output of the band pass filter(150) with the first threshold. In case the output of the band pass filter(150) is higher than the first threshold, the first comparator(170) outputs a signal. The first demodulator(180) demodulates the output signal of the first comparator(170). The output part(190) outputs the output signal of the first demodulator(180) to the external of the infrared receiver. In case the output of the band pass filter(150) is lower than the first threshold, the second comparator(200) compares the output of the band pass filter(150) with the second threshold. The second demodulator(210) demodulates the output signal of the second comparator(200) and outputs it to the gain controller(160).
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