73M1822/73M1922 Data Sheet
DS_1x22_001
3.4.2 Call Progress Monitor
The Call Progress Monitor monitors activities on the line. The audio output contains both transmit and
receive data with a configurable level individually set by Register 0x10.
Figure 8 shows the frequency response of the Call Progress Monitor Filter based upon the characteristics of
the device plus the external circuitry as shown.
Figure 8: Call Progress Monitor Frequency Response
C1 0.1uF R1 120K
R2
120K
LS1
AOUT
VCC
AT-2308
INTERVOX
R3 120K
4
1
5
8
-VIN VOUT1
CD
VOUT2
VCC
2
3
6
7
VREF1
VREF2 GND
V+
C3
+
C2
2.2uF
C4
1uF
U1
NJM2135
1uF
Figure 9: Demo Board Circuit Connecting AOUT to a Speaker
Table 12: Component Values for the Speaker Driver
Quantity Reference
Part Description
Ceramic capacitor
Ceramic capacitor
Ceramic capacitor
Sound transducer
1/8 W resistor
Part
1
1
2
1
3
1
C1
0.1 μF
C2
C3, C4
LS1
2.2 μF (optional)
1 μF
Speaker (Intervox)
120 kΩ
R1, R2, R3
U1
Audio amplifier
NJM2135 (New Japan Radio)
All measurements are at the AOUT pin with CMVSEL=0. Note that when CMVSEL=1, the peak signal at
AOUT is increased to approximately 1.11 Vpk.
20
Rev. 1.6
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
