Preliminary Information
MH88625
Tables 1 & 2: Transmit and Receive Gain Programming
Transmit
Gain (dB)
RTX Resistor
Value (Ω)
Notes
+6.0
+4.0
No Resistor
38.3k
Results in 0dB overall gain when used with Mitel A-law codec (i.e.
MT8965)
+3.7
32.4k
Results in 0dB overall gain when used with Mitel µ-law codec (i.e.
MT8964)
0.0
-3.0
GTX0 to GTX1
5.49k
-6.0
3.32k
-12.0
1.43k
Receive Gain
(dB)
RRX Resistor
Notes
Value (Ω)
+6.0
0.0
No Resistor
GRX0 to GRX1
5.49k
-3.0
-3.7
4.87k
Results in 0dB overall gain when used with Mitel A-law codec (i.e.
MT8965)
-4.0
4.64k
Results in 0dB overall gain when used with Mitel µ-law codec (i.e.
MT8964)
-6.0
3.32k
1.43k
-12.0
Note 1: See Figures 3 and 4 for additional details.
Note 2: Overall gain refers to the receive path of PCM to 2-wire, and transmit path of 2-wire to PCM.
Table 3: Input Impedance Settings
Z2
Z1
Z600
Z900
Resulting input impedance (Zin)
NA
NA
Connect Z1 to Z600
NA
600Ω
900Ω
Connect Z1 to
Z900
Connect network from Z1 to Z2
NA
NA
Connect Z1 to
Z900
NA
0.1 x impedance between Z1 & Z2
Note 1: NA indicates high impedance (10kΩ) connection to this pin does not effect the resulting network balance.
Note 2: See Figure 4 & 5 for Applications Circuits.
Table 4: Network Balance Settings.
NS (Input)
N2
N1
NATT
Resulting input impedance (Zin)
Low
NA
NA
NA
NA
Equivalent to Zin
High
AT&T compromise (350Ω + 1kΩ //
210nF)
Connect N1 to NATT
Zin must be 600Ω
High
Connect network from N1 to
AGND equivalent to 10 x
NETBAL. Connect network
from N1 to N2 equivalent to 10
x Zin.
NA
0.1 x impedance between N1 & N2
Note 1: NA indicates high impedance (10kΩ) connection to this pin does not effect the resulting network balance.
Note 2:Low indicates Logic Low.
Note 3: See Figures 6 and 7 for Application Circuit.
2-193
MITEL [ MITEL NETWORKS CORPORATION ]
