MSTM-S3-TR-19.44M

Overview

The Connor Winfield MSTM-S3-TR-19.44M is a Stratum 3 timing module designed for Ethernet and telecom applications compliant with GR-1244 Issue 2 and GR-253 Issue 3. It operates on a 4.75V to 5.25V supply, drawing 250mA typically. The module accepts an external reference input of 19.44 MHz and provides two synchronous outputs (Sync_Out and Opt_Out) ranging from 8 kHz to 77.76 MHz. It features redundant references, 40-second holdover history, and operational status flags via control pins A and B.

Feature Summary

• Stratum 3 compliance with GR-1244 and GR-253 standards
• Dual synchronous outputs (Sync_Out and Opt_Out) from 8 kHz to 77.76 MHz
• Redundant reference inputs with 40-second filtered holdover history
• Operational mode selection via CNTL A/B pins (Holdover, Ref 1, Ref 2, Free Run)

Applications

• System clock modules for Stratum 3 timing networks
• Ethernet synchronization equipment
• BITS (Building Integrated Timing Supply) systems

Procurement Notes

Verify the specific output frequency configuration required for the Opt_Out pin, as this is determined by the ordering suffix. Confirm that the host system can provide the necessary peak current of approximately 400 mA during the OCXO warm-up period. Ensure the PCB layout accommodates the 18-DIP package dimensions and recommended solder mask specifications.

Selection Notes

Select this module when a complete Stratum 3 timing solution is needed for GR-1244/GR-253 environments. The 19.44 MHz input reference must match the available network clock source. Consider the 0°C to 50°C operating temperature range; wider ranges require different thermal configurations. Verify if the simplified control interface meets the system's monitoring requirements compared to full-featured STM modules.

Part Context

This component belongs to the MSTM-S3 series of Simplified Control Timing Modules. It serves as a cost-effective alternative to complex timing designs by integrating redundant references and holdover capabilities into a single 18-pin DIP package. It is functionally comparable to legacy units like the TF Systems TF118B and Raltron SY0001B.

Replacement Considerations

Publicly confirmed substitutes include the TF Systems TF118B and Raltron SY0001B. These units serve similar roles in Stratum 3 timing applications but may differ in pinout or control logic details.