IMPEDANCE MATCHING CIRCUIT INSIDE OF LOW LEVEL PROCESSOR BOARD IN MOBILE SWITCHING CENTER

摘要

PURPOSE: An impedance matching circuit inside of a low level processor board in the mobile switching center is provided to prevent the malfunction of a central processing unit, generated due to the reflection effect of a signal outputted from a RS-232C driver. CONSTITUTION: A RS-232C interface part(110) converts an analog signal received through a 232C connector(130) into a digital signal. A first full-down resistance(120) carries out a function to down the level of a data signal outputted from the RS-232C interface part(110) to be operated normally in data transmission. The 232C connector(130) performs an interface function so that the data signal transmitted from the first full-down resistance(120) can be inputted in an external device. A capacitor(140) carries out a function to prevent a data signal received from an external device through the 232C connector(130) from being distorted by noise. A second full-down resistance(150) carries out a function to down a reflective signal level so that a receiving data signal transmitted by reflection phenomenon through the capacitor(140) cannot have an effect on the processor part inside of a low level processor in the mobile switching center.