MT9044AL1 Zarlink Semiconductor, Inc., MT9044AL1 Datasheet - Page 20

• Manufacturer Part Number: MT9044AL1
• Description: Dual Reference Frequency Selectable Digital PLL with Multiple Clock Outputs for T1/E1 (ITU-T G.812 type IV), Stratum (3, 4, 4E) and STS-3/OC3 Systems
• Manufacturer: Zarlink Semiconductor, Inc.

MT9044
Single Reference Source E1 to STS-3 with 8 kHz
Reference
The device may operate in freerun mode or with a
single reference source. The 8 kHz output from the
MT9075 is sourced from the clock extracted from the
E1 trunk. It becomes the reference for the PLL which
then generates ST-BUS signals F0o, C4o and C2o to
form the system backplane clock. The MT90840
connects to the system backplane, as well as to an
OC3 link via an STS-3 Framer and optical link. The
19.44 Mhz clock required by the MT90840 is
generated by the MT9044. In the event that the E1
link is broken, the LOS output of the MT9075 goes
high placing the MT9044 in freerun mode.
20
To OC3 Line
RX Line
TX Line
XFMR
XFMR
To E1 Line
RX Line
To
To
TX Line
XFMR
XFMR
To
To
PPFRi
PDo0-7
PPFTo
PDi0-7
PCKR
TTIP
TRING
RTIP
RRING
MT90840
Figure 17 - Single Source - E1 to STS-3 with 8kHz Reference
MT90820
MT9075
STo0-7
STo1-8
STi0-7
STi1-8
PCKT
RxFP
DSTo
STo0
DSTi
LOS
STi0
C4b
C4i
C4i
F0i
F0i
F0i
1kΩ
10nF
10kΩ
PRI
LOS1
LOS2
TCLR
RST
MS1
MS2
RSEL
MT9044
+ 5V
C1.5o
ACKo
OSCi
C19o
ACKi
C4o
FS1
FS2
F0o
GTi
+ 5V
Out
20MHz
CLOCK
±
32ppm