RxA2 15
RxA1 16
TxD 11
RxA2 15
RxA1 16
TxD 11
RxA2 15
RxA1 16
TxD 11
RxA2 15
RxA1 16
TxD 11
–
LOW–BAND
+
AAF S/H
BPF
CARRIER
DETECT
3 CD
AC
AMP
DEMOD
5 RxD
1
DSI
MODULATOR
HIGH–BAND
BPF
SMOOTHING
FILTER
–
+
(a) Originate/Channel 1 Mode (MODE = High, LB = Low)
17 TxA
18
Exl
–
AAF S/H
LOW–BAND
+
BPF
CARRIER
DETECT
3 CD
AC
AMP
DEMOD
5 RxD
1
DSI
MODULATOR
HIGH–BAND
SMOOTHING
–
BPF
FILTER
+
(b) Answer/Channel 2 Mode (MODE = Low, LB = Low)
17 TxA
18 Exl
–
+
AAF S/H
LOW–BAND
BPF
CARRIER
DETECT
AC
AMP
DEMOD
MODULATOR
HIGH–BAND
BPF
SMOOTHING
FILTER
–
+
(c) Originate/Channel 1 Mode and Analog Loopback State (MODE = High, LB = Low)
–
AAF S/H
+
LOW–BAND
BPF
CARRIER
DETECT
AC
AMP
DEMOD
MODULATOR
HIGH–BAND
BPF
SMOOTHING
FILTER
–
+
(d) Answer/Channel 2 Mode and Analog Loopback State (MODE = Low, LB = Low)
Figure 4. Basic Operating Modes
3 CD
5 RxD
1 DSI
17 TxA
18 Exl
3 CD
5 RxD
1 DSI
17 TxA
18 Exl
MOTOROLA
MC145442•MC145443
7