INFRARED REMOTE CONTROLLER RECEIVING SYSTEM AND METHOD FOR CONTROLLING MEAN FREQUENCY OF FILTER

摘要

PURPOSE: An infrared remote controller receiving system and a method for controlling a mean frequency of a filter are provided to reduce time required for wafer testing by controlling a mean frequency of a filter without trimming a resistance. CONSTITUTION: A remote control signal is received from a remote controller transmission system through a photodiode(17). The photodiode(17) converts the remote control signal in a light form into a current form. An amplifier(11) amplifies the remote control signal. A variable gain amplifier(12) receives an output of the amplifier(11), amplifies an original signal and a noise signal each with different gains. A filter(13) passes only a carrier frequency component, canceling other component. An automatic gain controller(15) receives an output of the filter(13), and discriminates the original signal and the noise signal so as for the variable gain amplifier(12) to control their gains. A sheath signal of an output of the filter(13) is extracted by a wave shaping circuit(14), A pulse signal corresponding to the remote control signal is generated from the wave shaping circuit(14) and transmitted to a microcomputer(18). The microcomputer(18) receives the pulse signal and performs an operation of a device desired by a user.