MT91L60AS MITEL [Mitel Networks Corporation], MT91L60AS Datasheet - Page 5

• Manufacturer Part Number: MT91L60AS
• Description: ISO2-CMOS 3 Volt Multi-Featured Codec (MFC)
• Manufacturer: MITEL [Mitel Networks Corporation]

Advance Information
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/ITU-T
control bit. The A/ control bit is logically OR’ed with
the A/
controllerless modes.
reside in Control Register 2 (address 04h). Table 1
illustrates these choices.
Transducer Interfaces
Standard handset transducer interfaces are provided
by the MT91L60. 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.
+ Full Scale
(quiet code)
- Full Scale
Code
+ Zero
-Zero
pin providing access in both controller and
Serial Port
Magnitude
PCM
D
0000 0000
D
1111 1111
1000 0000
0111 1111
PCM
in
out
Sign/
Both A/
Table 1
Transmit Filter
(1 dB steps)
Transmit Filter
(1 dB steps)
0 to +7 dB
0 to +7 dB
1000 0000
1111 1111
0111 1111
0000 0000
µ-Law
(1 dB steps)
Gain
Filter Gain
0 to -7 dB
Gain
Receive
Filter/Codec and Transducer Interface
ITU-T (G.711)
and Smag/ITU-T
Figure 3 - Audio Gain Partitioning
1010 1010
1101 0101
0101 0101
0010 1010
A-Law
-0.37 dB or 8.93 dB
INTERNAL TO DEVICE
Transmit Gain
(3.32 dB steps)
Side-tone
+9. 96 dB
-11 dB
-9.96 to
-6 dB
Default Bypass
• The handset speaker outputs (receiver), pins
Control of this gain is provided by the TxINC
control bit (Gain Control register 1, address 00h).
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.
MT91L60
HSPKR +
HSPKR -
Transmit
6.37 dB
Gain
Figure 4 - Handset Speaker Driver
-6.0 dB or
Receiver
Driver
0 dB
75
75
HSPKR +
HSPKR -
EXTERNAL TO DEVICE
M+
M-
75
75
Transmitter
Microphone
MT91L60
Receiver
Handset
(speaker)
150 ohm
(150 )
load
7-111