Analog Section - Panasonic KX-FG2452CX Service Manual

KX-FG2452CX
6.7.

Analog Section

1. Function
The analog section serves as an interface between the telephone line. The digital board (IC701) for transmission and recep-
tion of FAX signals, switches between the digital board (IC701) and other sections by means of a multiplexer in the NCU sec-
tion. The control signals to the individual analog sections are output mainly from ASIC IC501, and the status information for
the various sections is also held in ASIC IC501.
Simple explanations for the various sections are given below.
2. Circuit Operation
[NCU Section]
This is composed of a bell detection circuit, pulse dial generation circuit, CPC detect circuit, vox circuit, amplifier circuit for
line transmission and reception, sidetone circuit, Extension phone line off-hook detection circuit, Remote FAX activation
circuit.
[Modem (IC701)]
This is used for FAX signal tone modulation, DTMF signal transmission. The DTMF signal is placed into the TX system.
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