Panasonic KX-TA1232 Service Manual page 50

(7) CALLER ID CARD (KX-TA123293)
CALLER ID CARD consists of the following:
MODEM Signal Receiver Circuit
Serial/Parallel Converter Circuit
Over voltage Protector Circuit
MODEM Signal Receiver Circuit
Composition:
IC301, IC302, IC303, IC304, etc.
Circuit Operation
This circuit converts the MODEM signals sent between the bell signals into the serial signals. The
baud rate of the MODEM signals is 300 bps. This circuit is composed of one IC (IC301, IC302,
IC303, IC304), and four of this circuit are installed corresponding to each CO line.
Serial/Parallel Converter Circuit
Composition:
IC305, IC306, etc.
Circuit Operation:
This circuit converts the serial data presented from the MODEM signal demodulator into the
parallel data for the main CPU to read them.
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