Modular Master Clock System

Brandywine’s Modular Master Clock System represents the next generation of modular timing systems, the MMC is a leap forward in design.

At the center of the MMC system are Brandywine’s powerful dual-redundant Master Clock Modules (MCM). Each MCM may be synchronized by a variety of reference sources and uses the selected reference to steer an embedded oscillator to provide stable and accurate time and frequency for the MMC. Multiple references can be prioritized with automatic failover. Uniquely, the MCM will also validate the GPS reference based upon the inherent stability of the MCM oscillator, providing hardening against possible GPS spoofing.


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Modular Master Clock System - 1U Version

Model #MMC1U

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Modular Master Clock System - 2U Version

Model #MMC2U

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Model NumberDescriptionOscillator TypePower SupplyForm FactorPower TypeOutput FormatInput Format
MMC1UModular Master Clock System - 1U VersionOCXO, CSACAC, DC1UAC, DCHQ + 1PPS, IRIG, 1MHz, 5MHz, 10MHz, 1PPS, 50-bit BCD, XR3, 2137, NTPGPS, HQ + 1PPS, IRIG + 1PPS, 10MHZ
MMC2UModular Master Clock System - 2U VersionOCXO, CSAC, RubidiumAC, DC2UAC, DCHQ + 1PPS, IRIG, 1MHz, 5MHz, 10MHz, 1PPS, 50-bit BCD, XR3, 2137, NTPGPS, HQ + 1PPS, IRIG + 1PPS



  • Redundant design with multiple signal paths built in for high-availability.
  • 12 expansion slots in the 2U version and 5 expansion slots in the 1U variant.
  • Industry-first GPS integrity checking
  • Unique optical crosslink architecture for either Master-Slave hierarchical setups or Master-Master crosschecking and failover
  • 2U version is operated by an intuitive touch-screen interface, a first for any master clock system.
  • All components are hot-swappable and are dual redundant.
  • The Output Signal modules are hot-swappable from the front and minimize the need to disconnect cables.

Available input reference selections include GPS (C/A code and SAASM receivers are supported, with future support for M-Code planned), IRIG-B, Have Quick/1PPS and external 10 MHz.  In additional an MCM may be synchronized to up to 2 other MMC chassis using a fiber optic crosslink, this provides additional resiliency for the MMC time and frequency references.

The MMC supports multiple reference oscillator choices, including Rubidium (2U chassis only), Chip Scale Atomic Clock (CSAC) and Ovenized Oscillator (OCXO)

The output signals for the Modular Master Clock System are generated by up to 12 hot-swappable Output Signal Modules (OSM), and are ideal for custom solutions or future expansion.  Available modules include NTP, low-phase-noise frequency, time code modules such as IRIG A, B, G, H, and NASA 36, BCD, PPS, PPM, Have Quick as well as optical crosslink.

The MMC status and control is via a full color touch screen that allows control of the local chassis, as well as remote chassis that are connected via crosslink. Other control options are via a Windows application, and via SNMPv3.  User controls for the MMC are protected via password with encrypted storage. Network protocols also fully support privacy and authentication.