MT9092
transmisssion devices which connect directly with
the MT9092 to complete an application; the MT8930
(SNIC) and the MT8971/72 (DSIC/DNIC). An ISDN
4-wire "TE" function is implemented with the
MT8930/MT9092 combination. A 2-wire digital phone
for PABX, key-systems and other proprietary
applications is implemented with the MT8971/72/
MT9092 combination.
Applications
To maintain a fully differential topology in the
transmit path the suggested connection scheme for
the transmit microphones is shown in Figure 8.
However, it is possible to use a single-ended
arrangement as shown in Figure 9 for the transmit
interface. In this case the dynamic range of the
MT9092 is reduced by half. In both figures the output
drivers are connected in a fully differential manner.
Figures 10 and 11 show the 4-wire and 2-wire
applications, respectively.
The MT9092 is a member of the Mitel family of digital
terminal equipment components. There are two
330Ω
+
-
+5V
+
10µF
511Ω
0.1µF
100K
VBias
100K
R
R
Electret
Microphone
2R
T
+
T
Av = 1+
0.1µF
330Ω
511Ω
511Ω
-
+5V
+
+
+
-
10µF
0.1µF
100K
VBias
100K
R
2R
T
+
T
Av = 1+
Electret
Microphone
0.1µF
R
0.1µF
VBias
0.1µF
511Ω
+
-
+5V
6
5
4
3
2
1
44 43 42 41 40
+
40Ω nom.
32Ω min.
7
39
38
37
36
35
34
33
32
31
30
29
DSTi
ST-BUS
Port
8
9
DSTo
to
75Ω
Transmission
Device
C4i
F0i
10
11
12
150Ω
75Ω
1000pF
+5V
MT9092
IRQ
SCLK
1000pF
.1µF
13
14
DATA2
LCD
Serial
Microport
INTEL
1000pF caps
are optional
15
16
DATA1
CS
MCS-51
17
WD
Note: Single-ended configurations reduce
dynamic range by a factor of two.
18 19 20 21 22 23 24 25 26 27 28
LCD
Figure 8 - Application Circuit - fully differential audio input
7-32
MITEL [ MITEL NETWORKS CORPORATION ]
