MT9160 Datasheet, PDF (5/28 Pages) Mitel Networks Corporation – ISO2-CMOS 5 Volt Multi-Featured Codec (MFC)

Preliminary Information
MT9160
Companding law selection for the Filter/Codec is
provided by the A/µ companding control bit while
the coding scheme is controlled by the Smag/CCITT
control bit. The A/µ control bit is logically OR’ed with
the A/µ pin providing access in both controller and
controllerless modes. Both A/µ and Smag/CCITT
reside in Control Register 2 (address 04h). Table 1
illustrates these choices.
Code
+ Full Scale
+ Zero
-Zero
(quiet code)
- Full Scale
Sign/
Magnitude
1111 1111
1000 0000
0000 0000
0111 1111
CCITT (G.711)
µ-Law
A-Law
1000 0000 1010 1010
1111 1111 1101 0101
0111 1111 0101 0101
0000 0000 0010 1010
Table 1
Transducer Interfaces
Standard handset transducer interfaces are provided
by the MT9160. These are:
• The handset microphone inputs (transmitter),
pins M+/M-. The nominal transmit amplifier gain
may be adjusted to either 6.0 dB or 15.3 dB.
Control of this gain is provided by the TxINC
control bit (Gain Control register 1, address 00h).
• The handset speaker outputs (receiver), pins
HSPKR+/HSPKR-. This internally compensated
fully differential output driver is capable of driving
the load shown in Figure 4. The nominal handset
receive path gain may be adjusted to either 0 dB,
-6 dB or -12 dB. Control of this gain is provided
by the RxINC control bit (Gain Control register 1,
address 00h). This gain adjustment is in addition
to the programmable gain provided by the receive
filter.
HSPKR +
MT9160
75 Ω
150 ohm
load
(speaker)
75 Ω
HSPKR -
Figure 4 - Handset Speaker Driver
Serial Port
PCM
D_in
Filter/Codec and Transducer Interface
Default Bypass
Receive
Filter Gain
0 to -7 dB
(1 dB steps)
-6 dB
-6.0 dB or
0 dB
Receiver
Driver
Side-tone
-9.96 to
+9. 96 dB
(3.32 dB steps)
HSPKR +
75Ω
HSPKR -
75Ω
Handset
Receiver
(150Ω)
-11 dB
PCM
D_out
TTrraannssmmititFiFlteilrter
G_Ga_ain_in
(⁰10 dt^tooB+⁺s7t⁷edpB^ds)^B
(1 dB steps)
Transmit Gain
-0.37 dB or 8.93 dB
Transmit
Gain
6.37 dB
INTERNAL TO DEVICE
Figure 3 - Audio Gain Partitioning
M+
Transmitter
M- ^Microphone
EXTERNAL TO DEVICE
7-81