Advance Information
MT9041B
MT9041B
CLOCK
Out
20MHz ±32ppm
20MHz
MT9074
OSCi
F0o
TTIP
F0i
+ 5V
C4o
C4b
FS1
FS2
MS
TRING
REF
RST
OUT
E1.5o
LOS
IN0
IN1
IN2
IN3
IN4
IN5
IN6
IN7
RTIP
RRING
1kΩ
To Controller
Interrupt
+ 5V
10kΩ
10nF
MT9074
1 TO 8
MUX
TTIP
F0i
C4b
TRING
E1.5o
LOS
RTIP
RRING
To Controller
Interrupt
Figure 9 - Multiple E1 Reference Sources with MT9041B
Multiple E1 Reference Sources with MT9041B
In this example 8 E1 link framers (MT9074) are
connected to a common system backplane clock
using the MT9041B. Each of the extracted clocks
E1.5o go to a mux which selects one of the eight
input clocks as the reference to the MT9041B. The
clock choice is made by a controller using the loss of
signal pin LOS from the MT9074s to qualify potential
references. In the event of loss of signal by one of
the framers, an interrupt signals the controller to
choose a different reference clock. Disturbances in
the generated system backplane clocks C4b and F0b
are minimized by the phase slope limitations of the
MT9041B PLL. This ensures system integrity and
minimizes the effect of clock switchover on
downstream trunks.
9
MITEL [ MITEL NETWORKS CORPORATION ]
