MSTM-S3-TR Datasheet, PDF (2/16 Pages) Connor-Winfield Corporation – Stratum 3 Timing Module

General Description
The Connor-Winfield Stratum 3 Simplified Control Timing Mod-
ule acts as a complete system clock module for general Stratum
3 timing applications. The MSTM is designed to replace similar
units from TF Systems (TF118B) and Raltron (SY0001B).
Full external control input allows for selection and monitoring
of any of four possible operating states: 1) Holdover, 2) External
Reference #1, 3) External Reference #2, and 4) Free Run. Table
#1 illustrates the control signal inputs and corresponding opera-
tional states.
In the absence of External Control Inputs (A,B), the MSTM
enters the Free Run mode and signals an External Alarm. The
MSTM will enter other operating modes upon application of a
proper control signal. Mode 1 operation (A=1, B=0) results in an
output signal that is phase locked to the External Reference
Input #1. Mode 2 operation (A=0, B=1) results in an output sig-
nal that is phase locked to External Reference Input #2. Hold-
over mode operation (A=1, B=1) results in an output signal at or
near the frequency as determined by the latest (last) locked-
signal input values and the holdover performance of the MSTM.
Free Run ModeFree Run mode operation (A=0, B=0) is a guar-
anteed output of 4.6 ppm of the nominal frequency.
Alarm signals are generated at the Alarm Output during Hold-
over and Free Run operation. Alarm Signals are also generated
by Loss-of-Lock and Loss-of-Reference conditions. A high level
indicates an alarm condition. Real-time indication of the opera-
tional mode is available at unique operating mode outputs on
pins 1-4.
Control loop 0.1 Hz filters effectively attenuate any reference
jitter, smooth out phase transients, comply with wander transfer
and jitter tolerances.
Functional Block Diagram
Figure 1
1
CNTL A
2
CNTL B
3
4
Ex Ref 1
Ex Ref 2
Ref
Control
Free Run
Ref #1
Ref #2
Hold Over
Tuning
Voltage
Monitor
Free Run
PLL_TVL
Hold Over
Holdover
FIFO
Phase
Build Out
Circuit
LOL & LOR
DPLL
Alarm_Out
DAC
Stratum3
OCXO
Sync_Out
÷N
Reference
Clock
Opt_Out*
*Only one Opt_Out option is available per module
Table 1
CNTL
A
0
1
0
1
Function Control Table
CNTL
B
0
0
1
1
Operational
Mode
Free Run (Default Mode)
External
Reference
#1
Normal
PLL_Unlock
LOR
External
Reference
#2
Normal
PLL_Unlock
LOR
Hold Over
Ref 1
0
1
1
0
0
0
0
0
Ref 2 Hold Over Free Run PLL Unlock Alarm Out
0
0
1
0
0
0
0
0
0
0
1
0
1
0
0
1
0
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
1
Table 2
Symbol
V
CC
V_I
T_s
Parameter
Power Supply Voltage
Input Voltage
Storage Temperature
Absolute Maximum Rating
Minimum
-0.5
-0.5
-55
Nominal
Maximum
7.0
V_CC + 0.5
100
Units
Volts
Volts
deg. C
Notes
1.0
1.0
1.0
Data Sheet #: TM027 Page 2 of 16 Rev: P05 Date: 12 / 02 / 02
© Copyright 2001 The Connor-Winfield Corp. All Rights Reserved Specifications subject to change without notice