MSTM-SEC1 Datasheet, PDF (1/16 Pages) Connor-Winfield Corporation – Simplified Control Timing Module

2111 Comprehensive Drive
Aurora, Illinois 60505
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www.conwin.com
MSTM-SEC1
Simplified Control
Timing Module
US Headquarters:
630-851-4722
European Headquarters:
[phone]
General Description
The Connor-Winfield Stratum SEC1 (SDH
Equipment Slave Clock - Option 1) Control
Timing Module acts as a complete system
clock module for SDH Slave Clock timing
applications. The MSTM is designed for
external control functions. 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 operational 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=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 guaranteed output of 4.6 ppm of the
nominal frequency.
Alarm signals are generated at the
Alarm Output during Holdover and Free Run
operation. Alarm Signals are also generated
by loss-of-lock, loss of Reference, and a
Tune-Limit indication from the PLL. A Tune-
Limit alarm signal indicates that the VCXO
tuning voltage is approaching within 10%
the limits of its lock capability and that the
External Reference Input may be erroneous.
A high level indicates an alarm condition.
Real time indication of the operational mode
is available at unique operating mode
outputs on pins 1-4.
Control loop filters effectively attenuate
any reference jitter and smooth out phase
transients.