MT8941 Mitel Networks Corporation, MT8941 Datasheet - Page 12

• Manufacturer Part Number: MT8941
• Description: CMOS ST-BUS FAMILY Advanced T1/CEPT Digital Trunk PLL
• Manufacturer: Mitel Networks Corporation

MT8941
Figures 11 and 12 show how the MT8941 can be
used to synchronize the ST-BUS to the CEPT
transmission link at the master and slave ends.
Generation of ST-BUS Timing Signals
The MT8941 can source the properly formatted ST-
BUS timing and control signals with no external
inputs except the crystal clock. This can be used as
the standard timing source for ST-BUS systems or
any other system with similar clock requirements.
3-54
Crystal Clock
(16.384 MHz)
Crystal Clock
(16.384 MHz)
Figure 12 - Synchronization at the Slave End of the CEPT Digital Transmission Link
CMOS
MS0
MS1
MS2
MS3
F0i
C12i
EN
C8Kb
C16i
EN
EN
Ai
Bi
V
SS
CV
C4o
C2o
C
Figure 13 - Generation of the ST-BUS Timing Signals
MT8941
MS0
MS1
MS2
MS3
F0i
C12i
EN
C8Kb
C16i
EN
EN
V
RST
SS
CV
C4o
C2o
C
MT8941
C4o
C4b
C2o
C2o
RST
V
F0b
DD
R
V
C4b
C2o
F0b
V
DD
Y
DPLL #1 - NOT USED
DPLL #2 - FREE-RUN MODE
(MS0=0; MS1=0;MS2=1;
MS3=1)
ST-BUS
TIMING
SIGNALS
DD
o
R
V
DPLL #1 - NOT USED
DPLL #2 - NORMAL MODE
(MS0=0; MS1=0;
MS2=1; MS3=1)
DD
Figure 13 shows two such applications using DPLL
#2. In one case, the MT8941 is in FREE-RUN
mode with an oscillator input of 16.384 MHz. In the
other case, it is in NORMAL mode with the C8Kb
input tied to V
does not make any corrections and therefore, the
output signals are free from jitter.
completely free.
For prototyping purposes, Mitel offers the MT8941
Crystal Kit (MB6022) which contains 16.384 MHz
and 12.352 MHz clock oscillators.
Crystal Clock
(16.384 MHz)
DPLL #1 - NOT USED
DPLL #2 - NORMAL (MS0=1; MS1=0; MS2=1; MS3=1)
C2i
F0i
E8Ko
MH89790B
Mode of Operation for the MT8941
OUTA
OUTB
DSTo
CSTo
CSTi0
CSTi1
DSTi
RxR
RxT
DD
. For these applications, DPLL #2
TRANSMIT
RECEIVE
MS0
MS1
MS2
MS3
F0i
C12i
EN
C8Kb
C16i
EN
EN
Ai
Bi
V
SS
CV
C4o
C2o
C
MT8941
RST
MULTIPLEX
C4o
C4b
C2o
C2o
V
F0b
MT8980/81
PRIMARY
DIGITAL
DD
SWITCH
ST-BUS
CEPT
LINK
R
DPLL #1 is
V
ST-BUS
TIMING
SIGNALS
DD