XRT8001 Datasheet, PDF (1/48 Pages) Exar Corporation – WAN Clock for T1 and E1 Systems

XRT8001
WAN Clock for T1 and E1 Systems
GENERAL DESCRIPTION
The XRT8001 WAN Clock is a dual-phase-locked loop
chip that generates two very low jitter output clock
signals that can be used for synchronization clocks in
wide area networking systems. The XRT8001 has pre-
programmed multipliers and dividers that are selected
via the serial port. It generates two integer multiples of
8kHz, 56kHz, and 64kHz while locked onto an incom-
ing reference of 1.54MHz (T1), 2.048MHz (E1), 8kHz,
56kHz, or 64kHz
The XRT8001 WAN Clock can be configured to oper-
ate in one of six modes:
1. The Forward/Master Mode
2. The Reverse/Master Mode
3. The “Fractional T1/E1" Reverse/Master Mode
4. The “E1 to T1 - Forward/Master" Mode
5. The “High Speed - Reverse" Mode
6. The “Slave” Mode
FEATURES
• Dual Phased Locked Loops with
Pre-Programmed Multipliers and Dividers
• Pre-Programmed with Popular Frequency
Conversions for Communications Systems
October 2001-1
• Generates Output Clock Frequencies Ranging
From 8kHz up to 16.384MHz
• Serial Port Control for Optimal Performance
• Sync Output: 8kHz or 64kHz
• Low Jitter
• Cascadable (Master / Slave Modes)
• No External Components Needed
• Pin Compatible with the XRT8000
• Low Power (3.3V or 5V): 40 - 100mW
• - 40°C to +85°C Temperature Range
• 18-Lead PDIP or SOIC Packages
APPLICATIONS
• T1/E1 Access Equipment (DSU/CSU)
• Frame Relay Access Devices (FRAD)
• Basic Rate and Primary Rate ISDN Equipment
• ISDN Routers
• Terminals
• Remote Access Servers
• T1/E1 Concentrators
• T1/E1 Multiplexers
• T1/E1 Clock Rate Converters
• Internal Timing Generators
• System Synchronizers
3.3V or 5V
Reference Clock
8kHz to 16.384 MHz
Sync Out
8kHz or 64kHz
V CC
FIN
3
XRT8001
SYNC
2
CLK1
6
CLK2
13
Clock Output 1
Clock Output 2
Master/Slave
MSB
8
LOCKDET
11
CS SDO SDI SCLK
µC/µ P Serial I/O
PLL Lock Detect
Figure 1. System Diagram
ORDERING INFORMATION
Part Number
XRT8001IP
XRT8001ID
Package
18-Lead 300 Mil PDIP
18-Lead 300 Mil JEDEC SOIC
Operating Temperature Range
-40°C to +85°C
-40°C to +85°C
Rev. 1.01
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 • [phone] • FAX [phone] • www.exar.com