Pre-amplifier for an infrared remote control receiver for receiving remote control signals which are pulse-code modulated onto an RF carrier frequency

摘要

In the case of a pre-amplifier for an infrared remote control receiver for receiving remote control signals which are modulated onto an RF carrier frequency, the signals are supplied after demodulation to a comparator circuit which separates the useful signal from the noise and interference signals. The amplitude of the useful signal changes depending on the distance between the infrared transmitter and receiver. The rectangular waveform pulses which are to be evaluated by the remote control evaluation circuits are, however, intended to have identical amplitudes and lengths. This is achieved in that the comparator threshold is continuously matched to the amplitude of the received useful signal.