MT9173AE Mitel Networks Corporation, MT9173AE Datasheet - Page 15

• Manufacturer Part Number: MT9173AE
• Description: Digital Subscriber Interface Circuit with RxSB
• Manufacturer: Mitel Networks Corporation

Preliminary Information
Applications
Typical connection diagrams are shown in Figures 13
and 14 for the DN mode as a MASTER and SLAVE,
respectively. L
transformer through a resistor R2 and capacitors C2
and C2’ to match the line characteristic impedance.
Suggested values of R2, C2 and C2’ for 80 and 160
kbit/s operation are provided in Figures 13 and 14.
Overvoltage protection is provided by R1, D1 and
D2. C1 is present to properly bias the received line
signal for the L
used to couple to the line with a secondary center
tap for optional phantom power feed. Varistors have
been shown for surge protection against such things
as lightning strikes.
+5V
DV Port ST-BUS
CD Port ST-BUS
+5V
DV Port ST-BUS
CD Port ST-BUS
Master Clocks
Mode Select
Master Clocks
Mode Select
Lines
Measurement
To hardware
Lines
(optional)
0.33 F
0.33 F
Indicator
To Time
Circuitry
0.33 F
0.33 F
SYNC
IN
OUT
{
{
{
input. A 2:1 coupling transformer is
{
{
{
is connected to the coupling
Figure 13 - Typical Connection Diagram - MAS/DN Mode, 160 kbit/s
Figure 14 - Typical Connection Diagram - SLV/DN Mode, 160 kbit/s
DSTi
DSTo
CDSTi
CDSTo
F0
C4
MS0
MS1
MS2
V
V
RxSB
Ref
Bias
DSTi
DSTo
CDSTi
CDSTo
F0
C4
MS0
MS1
MS2
V
V
RxSB
MT9173/74
MT9173/74
Ref
Bias
OSC1
OSC2
L
OSC1
OSC2
OUT
L
L
F0o
OUT
IN
L
To Next DNIC
IN
NC
R2 = 390
R1 = 47
R2 = 390
R1 = 47
10.24 MHz XTAL
C3=33pF=C4
D.C. coupled,
Frequency locked
10.24 MHz clock.
Refer to AC Electrical
Characteristics
DN Mode.
Clock Timing
C2’ = 1.5 nF
C2’ = 1.5 nF
C2 = 22 nF
C2 = 22 nF
If the scramblers power up with all zeros in them,
they are not capable of randomizing all-zeros data
sequence. This increases the correlation between
the transmit and receive data which may cause loss
of convergence in the echo canceller and high bit
error rates.
In DN mode the insertion of the SYNC pattern will
provide enough pseudo-random activity to maintain
convergence. In MOD mode the SYNC pattern is not
inserted. For this reason, at least on ”1” must be fed
into the DNIC on power up to ensure that the
scramblers will randomize any subsequent all-zeros
sequence.
C1 = 0.33 F
Note: Low leakage diodes (1 & 2) are required so
D2
+5V
that the DC voltage at L
Note: Low leakage diodes (1 & 2) are required so
that the DC voltage at L
D1 = D2 = MUR405
+5V
D1 = D2 = MUR405
D2
2:1
2 : 1
C1 = 0.33 F
1.0 F
1.0 F
IN
IN
For 80 kbit/s: C2’ = 3.3 nF
For 80 kbit/s: C2’ = 3.3 nF
Line Feed
Voltage
V
V
Bias
Bias
MT9173/74
Supply
68 Volts
(Typ)
2.5 Joules
0.02 Watt
68 Volts
(Typ)
2.5 Joules
0.02 Watt
9-151