MT9043 Zarlink Semiconductor, MT9043 Datasheet - Page 7

• Manufacturer Part Number: MT9043
• Description: T1/E1 System Synchronizer
• Manufacturer: Zarlink Semiconductor

Lock Indicator - If the PLL is in frequency lock (frequency lock means the center frequency of the PLL is identical to
the line frequency), and the input phase offset is small enough such that no phase slope limiting is exhibited, then
the lock signal will be set high. For specific Lock Indicator design recommendations see the Applications - Lock
Indicator section.
Output Interface Circuit
The output of the DCO (DPLL) is used by the Output Interface Circuit to provide the output signals shown in Figure
5. The Output Interface Circuit uses four Tapped Delay Lines followed by a T1 Divider Circuit, an E1 Divider Circuit,
and a DS2 Divider Circuit to generate the required output signals.
Four tapped delay lines are used to generate 16.384MHz, 12.352MHz, 12.624MHz and 19.44 MHz signals.
The E1 Divider Circuit uses the 16.384MHz signal to generate four clock outputs and five frame pulse outputs. The
C8o, C4o and C2o clocks are generated by simply dividing the C16o clock by two, four and eight respectively.
These outputs have a nominal 50% duty cycle.
The T1 Divider Circuit uses the 12.384MHz signal to generate the C1.5o clock by dividing the internal C12 clock
by eight. This output has a nominal 50% duty cycle.
The DS2 Divider Circuit uses the 12.624 MHz signal to generate the clock output C6o. This output has a nominal
50% duty cycle.
The frame pulse outputs (F0o, F8o, F16o, TSP, and RSP) are generated directly from the C16 clock.
The T1 and E1 signals are generated from a common DPLL signal. Consequently, all frame pulse and clock outputs
are locked to one another for all operating states, and are also locked to the selected input reference in Normal
Mode. See Figures 14 & 15.
Figure 5 - Output Interface Circuit Block Diagram
DPLL
From
Tapped
Tapped
Tapped
Tapped
Delay
Delay
Delay
Delay
Line
Line
Line
Line
Zarlink Semiconductor Inc.
MT9043
12MHz
16MHz
19MHz
12MHz
7
DS2 Divider
T1 Divider
E1 Divider
C19o
C1.5o
C2o
C4o
C8o
C16o
F0o
F8o
F16o
RSP
TSP
C6o
Data Sheet