T7507 Quad PCM Codec with Filters,
Termination Impedance, and Hybrid Balance
Data Sheet
August 1999
Return Loss
The following template is achieved.
Chip Set Performance Specifications
(continued)
Gain Flatness—Out of Band—Low
Frequencies
Transmit direction only, loss relative to 1020 Hz. This
specification is met by using the T7507, L8567 SLIC,
L7583 solid-state switch, and 50
Ω
protection resistors
(200
Ω
+ 680
Ω
|| 0.1 µF termination).
Table 23. Gain Flatness—Out of Band—Low
Frequencies
Frequency (Hz)
16.67
40
50
60
Min Loss (dB)
30
26
30
30
18
RL (dB)
14
300 500
2000
3400
FREQUENCY (Hz)
5-5325(F)
Figure 8. Return Loss
Hybrid Balance
The following template is achieved.
Loss vs. Level Relative to Loss at –10 dBm
Input at 1020 Hz
This specification is met by using the T7507, L8567
SLIC, L7583 solid-state switch, and 50
Ω
protection
resistors (200
Ω
+ 680
Ω
|| 0.1 µF termination).
20
TBRL (dB)
16
1.6
300 500
2500
3400
FREQUENCY (Hz)
5-5326(F)
Figure 9. Hybrid Balance
0.6
LOSS (dB)
0.3
0
–0.3
–0.6
–55 –50
–40
–10
+3 dBm0
–1.6
5-5341(F)
Figure 7. Loss vs. Level
22
Lucent Technologies Inc.
AGERE [ AGERE SYSTEMS ]
