MSTM-S3

V_CC Power supply voltage (Vcc to GND)............ -0.5 to +7.0 Volts
V_IN Input voltage with respect to ground... -0.5 Vcc to +.05 Volts
T_STG Storage temperature .......................-65.0 to +150.0 Deg. C 
Note 1.0: Operation of this device at these or any other conditions beyond those listed under Recommended Operating Conditions is not implied. Exposure to Absolute Maximum Ratings conditions for extended periods of time may affect device reliability.

The Connor-Winfield Stratum 3 Miniature Simplified Control Timing Module MSTM-S3 acts as a complete system clock module for general Stratum 3 timing applications. The MSTM is designed for external control functions. Full external control input allows for selections and monitoring of any of four possible operating states: 1) Holdover, 2) External Reference #1, 3) External Reference #2, and 4) Free Run. The table below illustrates the control signal inputs and corresponding operational states:

In the absence of External Control Inputs (A,B), the MSTM MSTM-S3 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 signal that is phase locked to External Reference Input #2. Holdover mode operation of MSTM-S3 (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.

Alarm signals of MSTM-S3 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 by a Tune-Limit indication from the PLL. A Tune-Limit alarm signal indicates that the OCXO 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 MSTM-S3 is available at unique operating mode outputs on pins 1-4.

Control loop filters of MSTM-S3 effectively attenuate any reference jitter and smooth out phase transients.