PEB 2091
PEF 2091
Functional Description
Note 19: It may be necessary to use a multiplexer for the PLL-reference clock because
the CLS-signal is available only if the corresponding line is active. If the
referenced line is not active the PLL must be supplied by the CLS of another
active IEC-Q of the PBX.
XIN/XOUT
A free running crystal or other clock source should provide a 15.36-MHz base clock (see
also "External Circuitry", page 249 for more informations about crystal properties).
CLS
A 512 kHz clock synchronous to the PTT is provided. This clock should be used as the
reference clock for the PLL. It is not available in power down.
3.7.4
Repeater Modes
15.36 MHz
512 KHz
15.36 MHz
CLS
PLL
U
U
XIN XOUT
CLS
XIN
DCL
DCL
Interface
Interface
NT-RP
LT-RP
FSC
Synchr.
Synchr.
(Downstream)
(Downstream)
Figure 35
Clock Generation in Repeater Mode
In repeater applications the NT repeater issues IOM®-2 clocks for direct use in the LT
repeater. The LT repeater is synchronized to the upstream unit through the NT repeater.
To achieve this, a PLL is required to provide a synchronized 15.36 MHz master clock to
the LT repeater.
Semiconductor Group
87
Data Sheet 01.99
INFINEON [ Infineon ]
