T1/E1/J1/64KCC BITS Element

Industry's Only 64kHz Composite-Clock Transceivers

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The DS26502 is a building-integrated timing-supply (BITS) clock-recovery element. It also functions as a basic T1/E1 transceiver. The receiver portion can recover a clock from T1, E1, 64kHz composite clock (64KCC), and 6312kHz synchronization timing interfaces. In T1 and E1 modes, the Synchronization Status Message (SSM) can also be recovered. The transmit portion can directly interface to T1, E1, or 64KCC synchronization interfaces as well as source the SSM in T1 and E1 modes. The DS26502 can translate between any of the supported inbound synchronization clock rates to any supported outbound rate. A separate output is provided to source a 6312kHz clock. The device is controlled through a parallel, serial, or hardware controller port.
DS26502: Block Diagram DS26502: Block Diagram Enlarge+

Key Features

  • G.703 2048kHz Synchronization Interface Compliant
  • G.703 64kHz Centralized (Option A) and Codirectional Timing Interface Compliant
  • G.703 Appendix II 64kHz and 6312kHz Japanese Synchronization Interface Compliant
  • Interfaces to Standard T1/J1 (1.544MHz) and E1 (2.048MHz)
  • Interface to CMI-Coded T1/J1 and E1
  • Short- and Long-Haul Line Interface
  • Transmit and Receive T1 and E1 SSM Messages with Message Validation
  • T1/E1 Jitter Attenuator with Bypass Mode
  • Fully Independent Transmit and Receive Functionality
  • Internal Software-Selectable Receive- and Transmit-Side Termination for 75Ω/100Ω/110Ω/120Ω T1, E1, and Composite Clock Interfaces
  • Monitor Mode for Bridging Applications
  • Accepts 16.384MHz, 12.8MHz, 8.192MHz, 4.096MHz, 2.048MHz, or 1.544MHz Master Clock
  • 64kHz, 8kHz, and 400Hz Outputs in Composite Clock Mode
  • 8-Bit Parallel Control Port, Multiplexed or Nonmultiplexed, Intel or Motorola
  • Serial (SPI) Control Port
  • Hardware Control Mode
  • Provides LOS, AIS, and LOF Indications Through Hardware Output Pins
  • Fast Transmitter-Output Disable Through Device Pin for Protection Switching
  • IEEE 1149.1 JTAG Boundary Scan
  • 3.3V Supply with 5V Tolerant Inputs and Outputs


  • BITS Timing
  • Rate Conversion

CAD Symbols and Footprints

  • DS26502L
  • DS26502L+
  • DS26502LB1
  • DS26502LN
  • DS26502LN+
  • Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

    Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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