Panasonic DX-600 Service Manual page 220

6.2.7 Line Control Circuit
The Line Control Circuit consists of CML relay, DP circuit, DAA (Direct Access Arrangement), Ring Detect
Circuit for power-save and DC hold circuit. A Jack for an external telephone, which can be used for either
an external telephone or an optional Handset Kit. The block diagram of the Line Control Circuit is shown
below.
Line
Connect only to
one module
+
Ringer
IC
-
+
Speech
IC
-
Optional Handset Kit
Edition 1.0
SC PCB
CML Relay
External
Telephone
Jack
~
~
Hook SW
~
~
Ringer Signal Detection,
TAM I/F,
DTMF Remote Detection
Off-Hook
Detection
10MW
DP
Circuit
Si3015
DC Hold
Circuit
Ringer Signal
Detector
for Wake-up
(PC2)
MJR PCB
Line Control Circuit
220
DAA DAA
Line Control
I/F I/F
Si3021
(IC23) (IC24)
DP Control
PNL
DX-600/800
MODEM
MN195006
CPU
APR 2002