PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 86

• Manufacturer Part Number: PEF2091
• Description: ICs for Communications(ISDN Echocancellation Circuit)
• Manufacturer: Siemens Semiconductor Group

Semiconductor Group
3.7.3
Figure 34
In NT-PBX mode IOM
generated externally. In order to ensure synchronous timing to the PTT-master clock, a
PLL is used for generation of FSC and DCL (supplied to NT-PBX and LT devices) as well
as of the 15.36-MHz system clock (LT only).
Interface
Interface
Interface
NT-PBX
U
U
U
Clock Generation in NT-PBX Mode
(Downstream)
®
Synchr.
-2 clock signals are not issued by the device but need to be
LT
LT
LT
1
8
2
FSC
DCL
XIN
FSC
DCL
XIN
XIN
FSC
DCL
15.36 MHz
8 kHz
512-4096
kHz
86
PLL
%
FSC
DCL
512 kHz
512 kHz
FSC
DCL
FSC
DCL
512 kHz
CLS
CLS
CLS
(Downstream)
NT-PBX
NT-PBX
NT-PBX
CLS
(Reference Clock)
Synchr.
XIN XOUT
Functional Description
8
1
2
Data Sheet 01.99
Interface
Interface
Interface
U
U
U
PEB 2091
PEF 2091