73M1866B-IMR/F Maxim Integrated Products, 73M1866B-IMR/F Datasheet - Page 67

• Manufacturer Part Number: 73M1866B-IMR/F
• Description: MICRODAA SGL PCM HIGHWAY 42-QFN
• Manufacturer: Maxim Integrated Products
• Series: MicroDAA™r

Specifications of 73M1866B-IMR/F

• Includes: PCM Highway
• Function: Data Access Arrangement (DAA)
• Interface: PCM, Serial, SPI
• Number Of Circuits: 1
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 42-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -
• Power (watts): -

DS_1x66B_001
10.4 Billing Tone Rejection
Some countries use a large amplitude out-of-band tone to measure call duration and to allow remote
central offices to determine the duration of a call for billing purposes. To avoid saturation and distortion of
the input caused by these tones, it is important to be able to reject them. These frequencies are typically
12 kHz or 16 kHz.
The 73M1x66B has an integrated notch filter that attenuates either of these tones. By enabling this filter
and selecting the position of the notch frequency, such tones will be attenuated.
Figure 37 shows the magnitude response of the filter with a notch at either 12 kHz (F1) or 16 kHz (F2).
In addition to the notch filter, the 73M1x66B can indicate the presence of an overload condition when a
line’s AC voltage exceeds 3.5 Vpk.
Rev. 1.6
Figure 36: Magnitude Response of Impedance Matching Filter, ACZ (3:0)=0010 (ES 203 021-2)
F1db f 1000
F2db f 1000
F1db f 1000
(
(
(
⋅
⋅
⋅
−
10
10
50
0
)
)
)
10
10
20
30
40
50
10
Figure 37: Magnitude Response of Billing Tone Notch Filter
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0.5
2
1
4
1.5
6
Freq Response of IPMF, AZ=01
2
8
Sp ans 20kHz
kHz
2.5
f
10
f
3
12
73M1866B/73M1966B Data Sheet
3.5
14
4
16
4.5
18
5
5
20
20
67