AN2384 Freescale Semiconductor / Motorola, AN2384 Datasheet - Page 24

• Manufacturer Part Number: AN2384
• Description: Generic Tone Detection Using Teager-Kaiser Energy Operators on the StarCore SC140 Core
• Manufacturer: Freescale Semiconductor / Motorola

DTMF Q.24 Compliance Tests
24
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Generic Tone Detection Using Teager-Kaiser Energy Operators on the StarCore SC140 Core, Rev. 1
Mitel Side 1 Test 4: Amplitude ratio. This test determines the acceptable amplitude ratio in dB of both
tones in the digits 1, 5, 9, and D. In the first sequence, the H tone amplitude is maintained and the L
tone is attenuated so the amplitude ratio L/H varies from 0 to –20 dB (standard twist). In the second
sequence, the L tone amplitude is maintained and the H tone is attenuated so the amplitude ratio varies
from 0 to +20 dB (reverse twist). The AT&T requirements of the Q.24 standard require the amplitude
ratio of the first sequence to be –4 dB and
Key
D
1
5
9
Frequency
1209 Hz
1336 Hz
1477 Hz
1633 Hz
697 Hz
770 Hz
852 Hz
941 Hz
Table 7. Mitel Side 1 Test 3 Results Summary
+0.1 to +4%
–0.1 to –4%
+0.1 to +4%
+0.1 to +4%
+0.1 to +4%
+0.1 to +4%
+0.1 to +4%
+0.1 to +4%
+0.1 to +4%
–0.1 to –4%
–0.1 to –4%
–0.1 to –4%
–0.1 to –4%
–0.1 to –4%
–0.1 to –4%
-0.1 to -4%
Variation
RCFO%
RCFO%
RCFO%
RCFO%
RCFO%
RCFO%
RCFO%
RCFO%
RRB%
RRB%
RRB%
RRB%
RRB%
RRB%
RRB%
RRB%
+8 dB for the second sequence. The test passed.
Set-up 1
21 (P)
28 (P)
22 (P)
29 (P)
21 (P)
27 (P)
20 (P)
28 (P)
25 (P)
27 (P)
22 (P)
29 (P)
26 (P)
22 (P)
25 (P)
26 (P)
–0.15
–0.15
0.35
–0.2
–0.2
–0.2
5.0
5.1
4.7
4.8
5.1
0.1
5.1
4.8
5.1
0.2
Set-up 2
20 (P)
28 (P)
21 (P)
28 (P)
21 (P)
26 (P)
20 (P)
28 (P)
25 (P)
27 (P)
22 (P)
28 (P)
27 (P)
23 (P)
23 (P)
27 (P)
–0.15
–0.25
–0.2
–0.2
0.05
–0.2
0.35
4.9
5.1
4.8
4.8
5.2
5.1
4.8
5.1
0.1
Freescale Semiconductor
Set-up 3
21 (P)
28 (P)
22 (P)
30 (P)
21 (P)
27 (P)
21 (P)
28 (P)
26 (P)
27 (P)
24 (P)
29 (P)
27 (P)
23 (P)
27 (P)
30 (P)
–0.25
–0.15
–0.2
–0.2
–0.1
0.35
4.9
5.2
4.8
4.9
5.3
0.1
5.3
5.0
5.7
0